LIBRO DE REFRIGERACION

Executive Summary

EXECUTIVE SUMMARY

This Refrigerant Management Handbook (Handbook) includes everything the base civilengineer (BCE) needs to develop a Base Refrigerant Management Program (BRMP). TheBRMP will help the BCE manage refrigerants that have a damaging effect on the ozonelayer. These are part of a class of substances called ozone-depleting chemicals (ODC). Theymust be controlled to eliminate their dispersion into the atmosphere.

The policies and regulations that support the reduction of ozone depletion require the BCE tocarefully control refrigerants and monitor air conditioning/refrigeration (AC/R) equipment.These policies are:

The Montreal Protocol and subsequent amendments that placed a worldwide ban onthe production of chlorofluorocarbon (CFC) and hydrochlorofluorocarbon (HCFC)refrigerants starting in 1996 and 2031, respectively.

The Environmental Protection Agency (EPA) regulation issued in May 1993 tominimize CFC, HCFC and, starting on 15 November 1995, hydrofluorocarbon (HFC)emissions during operations, maintenance, repair, and disposal of refrigerant-usingequipment.

The Secretary and Chief of Staff of the Air Force Action Memorandum, date7 January 1993, which prohibits the purchase of any CFC refrigerants and AC/Requipment which use these refrigerants starting in June 1993. Exceptions are approvedonly by an Air Staff waiver.

To effectively manage AC/R equipment and regulated refrigerants, the BRMP, through thebase Refrigerant Manager (RM), focuses on conservation measures and the development of aRefrigerant Management Plan (RMP). The conservation measures will help the BCE meet theEPA requirements of minimal releases of refrigerant through improved servicing techniques,training and certifying technicians, and recording equipment maintenance and refrigerantusage. The RMP provides a plan to ensure adequate refrigerant supplies will be available tomeet mission needs until the last of the units using CFC refrigerants have achieved their fulleconomic life. The RMP provides a refrigerant inventory timeline that shows refrigerantconsumption rates, equipment retirements, and other activities which affect the inventory ofrefrigerant. An implementation schedule is part of the RMP. Its purpose is to assist inkeeping equipment retirement on schedule. A simple comparison of a plan’s projectedrefrigerant inventory quantity versus what is actually on-hand will tell the BCE whether thebase is meeting its goals or is in danger of a negative mission impact.

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Executive Summary

The Handbook includes all the information the RM needs to initiate and carry out a BRMP.The Handbook’s appendices cover the:

● National and Air Force policies on ODC refrigerants,● technical criteria for mechanical room design to support alternative refrigerants,● procedures for making a retrofit or replacement decision using life-cycle cost analysis,● methods to correctly size a replacement chiller or justify a central plant,● use of the Work Information Management System (WIMS) software for tracking refriger-

ant usage and equipment maintenance,● various types of funding available to pay for new conservation equipment and AC/R

units, and● conservation techniques for following EPA requirements.

This Handbook represents the Air Force’s resolve to protect the environment while meetingits global mission. As stated in the Secretary and Chief of Staff of the Air Force ActionMemorandum:

“The sooner we learn to live without these substances, the less likely we are to suffer amission stoppage because they are not available, and the less we will contribute to thedepletion of the earth’s ozone layer. ”

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Table of Contents

Table of Contents

Section

Chapter1.1

1.21.31.4

1.5

Page

l Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1Background . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11.1.1 Refrigerant Management Required . . . . . . . . . . . . . . . 1-11.1.2 CFCs and HCFCs - Class I and Class II Refrigerants . . . . . . . 1-1Air Force Goal . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1The Base Refrigerant Management Program . . . . . . . . . . . . . . 1-2Handbook Organization . . . . . . . . . . . . . . . . . . . . . . 1-2l.4.1 BRMP Elements . . . . . . . . . . . . . . . . . . . . . 1-2l.4.2 Appendix Summary . . . . . . . . . . . . . . . . . . . . . 1-2The Refrigerant Manager . . . . . . . . . . . . . . . . . . . . . . 1-41.5.1 RM’s Responsibilities . . . . . . . . . . . . . . . . . . . . 1-51.5.2 RM’s Capabilities . . . . . . . . . . . . . . . . . . . . . . 1-5

Chapter 2 Conservation Efforts for the Base Refrigerant Management Program . . . . . .2-12.12.2

2.3

2.4

2.5

Chapter3.13.23.33.43.5

Introduction . . . . . . . . . . . . . . .EPA Requirements . . . . . . . . . . . .2.2.1 Equipment Servicing and Repairs . . .2.2.2 EPA Maximum Leak Rates . . . . . .Air Force Requirements . . . . . . . . . .2.3.1 Managing Base Refrigerants . . . . .Training and Certification . . . . . . . . . .2.4.1 CerTest Module . . . . . . . . . .2.4.2 Local Vendors . . . . . . . . . . .BCE Conservation Methods . . . . . . . . .2.5.1 Leak Detection . . . . . . . . . . .2.5.2 AC/R Equipment Modifications . . . .2.5.3 WIMS Refrigerant Management Software2.5.4 Secure Storage Areas . . . . . . . .

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3 Refrigerant Management Plan Development . . . . . . . . . . . . . . 3-1Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1RMP Development Procedures . . . . . . . . . . . . . . . . . . . 3-1RMP Products . . . . . . . . . . . . . . . . . . . . . . . . . 3-1Metrics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1Step l: Equipment Survey . . . . . . . . . . . . . . . . . . . . . 3-23.5.l Survey Results: . . . . . . . . . . . . . . . . . . . . . . 3-2

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Section Page

3.6 Step 2: Equipment List.... . . . . . . . . . . . . . . . . . . .3.6.1 Equipment List Completion . . . . . . . . . . . . . . . . .

3.7 Step 3: Equipment Assessment Table . . . . . . . . . . . . . . . . .3.7.1 Value Determinations . . . . . . . . . . . . . . . . . . . .3.7.2 Subjective Considerations . . . . . . . . . . . . . . . . . .3.7.3 Method of Replacement . . . . . . . . . . . . . . . . . .

3.8 Step 4: Equipment Retirement Schedule and RefrigerantInventory Timeline . . . . . . . . . . . . . . . . . . .

3.8.1 Definition of Terms . . . . . . . . . . . . . . . . .3.8.2 Developing the Equipment Retirement Schedule . . . . . . . . .3.8.3 Refrigerant Inventory Tlmeline . . . . . . . . . . . . . . . .

3.9 Step 5: Project List and Funding Bar Chart . . . . . . . . . . . . . .3.9.1 Project List . . . . . . . . . . . . . . . . . . . . . . .3.9.2 Funding Bar Chart . . . . . . . . . . . . . . . . . . . . .3.9.3 Funding Bar Chart Analysis . . . . . . . . . . . . . . . . .

3.10 Step 6: The Implementation Schedule . . . . . . . . . . . . . . . . .3.10.1 Time Lengths . . . . . . . . . . . . . . . . . . . . . . .

3.11 Step 7: The RMP . . . . . . . . . . . . . . . . . . . . . . . . .

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Chapter 4 Refrigerant Management Plan Implementation . . . . . . . .4.1 The Philosophy . . . . . . . . . . . . . . . . . . . . .4.2 Overview of System Selection . . . . . . . . . . . . . .4.3 System Selection . . . . . . . . . . . . . . . . . . . .

4.3.1 Step 1: Cooling Load Analysis . . . . . . . . . . .4.3.2 Step 2: Retrofit vs Replacement . . . . . . . . . . .4.3.3 Step 3: Replacement Unit Selection . . . . . . . . .4.3.4 Step 4: Installing a Central Plant . . . . . . . . . .4.3.5 Step 5: Heat Recovery and Thermal Storage Technologies

4.4 System Selection Resources . . . . . . . . . . . . . . . .4.4.1 Personnel . . . . . . . . . . . . . . . . . . . .4.4.2 Tame . . . . . . . . . . . . . . . .4.4.3 Technical References . . . . . . . . . . . . . . .

4.5 Importance of fending . . . . . . . . . . . . . . . . . .

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Appendix A Update on Refrigerants: Translating the Laws, Regulations, andPolicies into Practice . . . . . . . . . . . . . . . . . . . . A-1

Appendix B Refrigerant Sensors and Monitoring of Equipment Rooms . . . . . . B-1Appendix C Refrigerant Storage Recommendations and Requirements . . . . . . . C-1Appendix D Refrigerant Leak Detection Methods and Equipment . . . . . . . . . . D-1

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Table of Contents

Section

Appendix E

Appendix F

Appendix G

Appendix H

Appendix IAppendix JAppendix KAppendix LAppendix MAppendix NAppendix OAppendix PAppendix QAppendix R

Page

Equipment to Reduce Refrigerant Release DuringMaintenance and Operation of Air Conditioning andRefrigeration Systems . . . . . . . . . . . . . . . . . . . . E-1Refrigerant Leak Mitigation through Equipment Maintenanceand Service Practices . . . . . . . . . . . . . . . . . . . . F-1AFCESA Work Information Management System (WIMS)Software Release 940715 . . . . . . . . . . . . . . . . G-1AC/R Equipment Survey Guide and Equipment Data CollectionSurvey Forms . . . . . . . . . . . . . . . . . . . . . . .. H-1Funding Alternatives for Base Refrigerant Management Program . . . . 1-1Application of ASHRAE Equipment Room Design Requirements . . . J-1AC/R Energy Conservation Devices . . . . . . . . . . . . . . . K-1Fundamentals of Cooling Load and Energy Analysis . . . . . . . . . L-1Evaluating Water Chillers for Replacement or Retrofit Potential . . . . M-1Chiller Selection Guide . . . . . . . . . . . . . . . . . . . . N-1Assessing the Potential of Central Chilled Water Plants . . . . . . . . O-1Heat Recovery Alternatives for Refrigerant Chillers . . . . . . . . . P-1Assessing the Potential of Thermal Energy Storage . . . . . . . . . Q-1Glossary of Terms and Definitions and Bibliography . . . . . . . . . R-1

List of Figures

Figure

Figure 1-1Figure 3-1Figure 3-2Figure 3-3Figure 3-4Figure 3-5Figure 3-6Figure 3-7Figure 3-8

Refrigerant Management Handbook Flowchart . . . . . . . . . . .Sample Completed Equipment List . . . . . . . . . . . . . . . .Sample Completed Equipment Assessment Table . . . . . . . . . .Sample Completed Equipment Retirement Schedule . . . . . . . . .Sample Completed Equipment Refrigerant Inventory Tlmeline . . . . .Sample Completed Project List . . . . . . . . . . . . . . . . .Sample Completed Funding Bar Chart . . . . . . . . . . . . . .Sample Completed Implementation Schedule . ., . . . . . . . . . .Sample of Table of Contents . . . . . . . . . . . . . . . . . .

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Chapter 1 — Introduction


1.1 Background

1.1.1 Refrigerant ManagementRequired

The Air Force Civil Engineer directed theAir Force Civil Engineer Support Agency(AFCESA) to develop base guidance formanaging refrigerant inventories to ensureall air conditioning and refrigeration(AC/R) equipment operates until the endof its economic life. This requirement wasin the Action Memorandum, 7 January1993, from the Secretary and Chief ofStaff of the Air Force implementing theAir Force ozone-depleting chemicals(ODC) policy. The memorandum was adirect result of the worldwide movement toreduce ODCS, including production bansstarting in January 1996.

1.1.2 CFCS and HCFCs - Class I andClass II Refrigerants

Chlorofluorocarbons (CFCs) and hydro-chlorofluorocarbons (HCFC) are ODCsand are categorized as Class I and II re-frigerants, respectively. The Environmen-tal Protection Agency (EPA) publishedregulation 40 C.F.R. Part 82 (1993) tominimize Class I and 11 emissions duringoperations, maintenance, repair, and dis-posal of refrigerant-using equipment. Theregulation applies to persons who workon this equipment as well as refrigerantreclaimers, equipment owners, and refrig-erant recycling and recovery equipment.The EPA may levy stiff fines for non-compliance (See Appendix A, Update on

Refrigerants: Translating the Laws, Regu-lations, and Policies into Practice).

1.2 Air Force Goal

The Air Force goal is to manage theinventory of regulated refrigerants andAC/R equipment to ensure uninterruptedmission support while operating thisequipment until the end of its economiclife. The maintenance procedures used bybase civil engineer (BCE) personnel mustbe compatible with the EPA’s environmen-tal compliance regulations. The RefrigerantManagement Handbook’s (Handbook)objective is to make each base self-suffi-cient in CFC refrigerants. It assists theBCE in developing a Base RefrigerantManagement Program (BRMP) to managerefrigerant resources and operate AC/Requipment to ensure continued missionsupport and environmental compliance.Using strong conservation procedures andlife-cycle costing methods, the BRMP willextend the availability of the existingrefrigerant supplies and prioritize equip-ment retirements. Although the emphasisis on CFCs and HCFCs, the Handbook’sprocedures to standardize operation andmaintenance practices should be applied toall refrigerants. It is also intended theHandbook be used by the base refrigerantmanager (RM) in developing the Refriger-ant Management Plan (RMP). Followingthe guidelines provided in the text andappendices, the RM will be able to suc-cessfully complete all essential elements ofthe RMP.

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1.3 The Base RefrigerantManagement Program

The BRMP implements refrigerant conser-vation procedures and develops a baseRMP that prioritizes AC/R equipmentretirements. The RMP includes graphs andtables to predict the rate of refrigerantconsumption, schedule equipment retire-ments, and identify the need for refrigerantto prevent negative mission impacts. TheRMP will ensure the availability of ade-quate refrigerant supplies through theremaining life of existing equipment. Itmust be updated periodically to accuratelyreflect the changes in funding and mission.

1.4 Handbook OrganizationThe Handbook contains four chapters thatdescribe how to establish the BRMP. Theappendices supplement the chapters onspecific technical topics. Figure 1-1,Refrigerant Management Handbook FlOW-chart, shows the relationship betweenchapters and appendices. The flowchart,highlighting the applicable chapter andappendices, also appears at the beginningof each chapter.

1.4.1 BRMP ElementsThe Handbook separates the BRMP intotwo elements:● recommendations to reduce refrigerant

consumption and meet EPA require-ments, and

● the development and implementation ofthe base RMP.

1.4.1.1 The first element, discussed inChapter 2, Conservation Efforts for the

Base Refrigerant Management Program,contains a set of recommended actions toreduce refrigerant consumption and helpthe BCE meet EPA requirements such as:● releasing minimal amounts of CFC and

HCFC refrigerants into theatmosphere,

● practicing refrigerant conservationservicing techniques,

● training and certifying technicians tohandle refrigerants,

● recording equipment maintenance andrefrigerant usage, and

● controlling refrigerant inventory.Integral to recording and controlling re-frigerant is the use of the Work Informa-tion Management System (WIMS) andWIMS Refrigerant Management Software.

1.4.1.2 The second element of the BRMPis addressed in Chapter 3, RefrigerantManagement Plan Development, and Chap-ter 4, Refrigerant Management Plan Imple-mentation. The RMP will help the basemanage its regulated refrigerants and theAC/R equipment that uses those refriger-ants. The RMP requires engineering andlife-cycle cost analyses to determine if aunit should be retrofitted to a non-CFCrefrigerant, replaced in kind, or replacedwith another type of equipment or process(such as a central plant or absorption unit).

1.4.2 Appendix SummaryFollowing is a summary of each appendix.Appendix A – details of applicable re-quirements of the Clean Air Act Amend-ments or CAAA, Title VI, and Air ForcePolicies to implement them;

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Figure 1-1. Refrigerant Management Handbook Flowchart

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Appendix B — descriptions, availability,and applications of refrigerant area moni-tors for use in mechanical rooms andrefrigerant storage areas;Appendix C — refrigerant storage require-ments for facilities and containers and safehandling of refrigerants;Appendix D — refrigerant leak detectionmethods and equipment for high- and low-pressure refrigerants when the equipmentis operating or idle, advantages and disad-vantages of portable units that pinpointleak locations, common equipment leaklocations;Appendix E — terms and reviews ofequipment used for recovery, recycling,and reclamation;Appendix F — major changes to refriger-ant leak mitigation procedures duringequipment servicing practices that willmeet EPA requirements and recommenda-tions;Appendix G — how the WIMS Refriger-ant Management Software helps the RMmonitor AC/R equipment and refrigerantusage;Appendix H — how to perform an Equip-ment Survey, providing the tools andpersonnel requirements and a line-by-lineexplanation of the equipment surveyforms;Appendix I — different funding avenuesthat can pay for refrigerant conservationequipment and AC/R equipment retirementprojects, including criteria and examples ofprogramming documents;Appendix J — mechanical equipmentroom design requirements for refrigerationsystems in ASHRAE 15-1992, Refrigerant-Quality Rule 4;Appendix K — use of energy conservationdevices for AC/R equipment;

Appendix L – calculations for a build-ing’s cooling load and energy usageanalysis (Appendices L, M, N, O, P, andQ have a distinct relationship in the selec-tion process. This relationship is showngraphically on the back of the tab of eachappendix);Appendix M — procedures and guidelinesfor evaluating replacement and retrofitoptions for existing water chillers by com-paring life-cycle costs taking into consider-ation age, mechanical condition, operatingefficiency, and criticality to the building(s)or system(s) they serve;Appendix N — guidelines and proceduresto select water chillers based on efficiency,availability of fuel sources, load matching,initial cost, and annual operating cost;Appendix O — guidelines for determiningthe potential to replace several individualchillers with a central plant that can be acombination of retrofitted and new chillersin a new structure or an expanded, existingmechanical room;Appendix P — guidelines for determiningwhen heat recovery chillers may be eco-nomically feasible by comparing the life-cycle cost of the alternatives;Appendix Q — guidelines for determiningwhen thermal energy storage systems(TESS) may be an economically feasiblealternative for integration into an existingor proposed chilled water system; andAppendix R — glossary of terms anddefinitions, and bibliography.

1.5 The Refrigerant Manager

The BRMP will be developed by the BCE-appointed RM. This Handbook provides

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the RM with the background, tools, andmethods needed to manage the base refrig-erant and equipment resources. The RMhas several responsibilities and mustpossess certain capabilities in order toaccomplish the job.

1.5.1 RM’s ResponsibilitiesThe RM must track: ●

●

●

●

●

●

refrigerant consumption by each pieceof equipment,base refrigerant inventory levels,consumption rates for each type ofrefrigerant,project cost and schedule for equipmentretirement,equipment service records and mainte-nance and repair requirements, andthe status of the AC/R technicians’training and certification.

1.5.2 RM’s CapabilitiesThe RM must:● be familiar with the WIMS Refrigerant

Management Software,● be able to use various spreadsheet and

graphics software,● have a working knowledge of the EPA

requirements governing the use ofregulated refrigerants,

● be able to do life-cycle cost and cool-ing load analysis on AC/R equipment,and

● understand procedures to justify differ-ent types of funding.

A team whose members share these capa-bilities and have access to other talent inthe BCE organization can perform theRM’s responsibilities. A possible dutylocation for the RM is in MaintenanceEngineering.

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Chapter 2 – Conservation Efforts for the Base Refrigerant Management Program

Chapter 2 — Conservation Efforts for theBase Refrigerant Management Program

2.1 Introduction

This chapter provides information andrecommendations on refrigerant conserva-tion that will aid the RM in establishingthe BRMP. The information and recom-mendations will help the RM comply withthe EPA and Air Force requirements thatpertain to both CFC and HCFC refriger-ants.

2.2 EPA Requirements

2.2.1 Equipment Servicing and RepairsDetailed requirements and information onaccomplishing equipment servicing andrepairs are found in Appendix E, Equip-ment to Reduce Refrigerant Release DuringMaintenance and Operation of Air Condi-tioning and Refrigeration Systems, andAppendix F, Refrigerant Leak Mitigationthrough Equipment Maintenance and Ser-vice Practices.

2.2.1.1 Technicians must be EPA certi-fied by 14 November 1994 to serviceAC/R equipment using CFC and HCFCrefrigerants.

2.2.1.2 Since 1 July 1992, no one couldknowingly release CFC or HCFC refriger-ants into the atmosphere. This will applyto hydrofluorocarbons (HFC) refrigerantsstarting 15 November 1995.

2.2.1.3 Anyone who disposes of AC/Requipment must recover the remaining

refrigerant and/or verify that the refriger-ant has been evacuated from the equip-ment.

2.2.1.4 Personnel who maintain, repair,or dispose of AC/R equipment must certifytheir recovery and recycling equipment toEPA.

2.2.1.5 Operators of equipment containing50 or more pounds of CFC- and HCFC-regulated refrigerants must keep up-to-dateservice records for the previous threeyears showing date, type of service, andquantity of refrigerant added-and pur-chased.

2.2.1.6 Commercial refrigeration equip-ment with over 50 pounds of refrigerant(that is, cold storage plants) must be re-paired of all leaks within 30 days if theequipment is leaking at a rate which willexceed 35 percent of the total chargeduring a 12-month period.

2.2.1.7 Equipment, other than commer-cial refrigeration, containing 50 or morepounds of refrigerant (that is, comfortcooling) must be repaired of all leakswithin 30 days if the unit leaks at a rateexceeding 15 percent of the total chargeduring a 12-month period.

2.2.1.8 Equipment does not require repairif, within 30 days after leak identification(as described in 2.2.1.6 and 2.2.1.7), aplan is developed for retirement of thatequipment within one year. A copy of theretirement plan must be available at thesite of the equipment.

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2.2.2 EPA Maximum Leak RatesThe following example shows how tocalculate the EPA maximum leak rates.This rate is shown in the WIMS Refriger-ant Consumption Rates - by Facility, Equi-pment, and Service Date report (seeAppendix G, Work Information Manage-ment System (W7MS)).

EXAMPLEAn office building is cooled by a 200-ton centrifu-gal chiller with an 800-pound CFC-12 refrigerantcharge. Fifteen pounds of CFC-12 were addedduring the last servicing. Because the chiller pro-vides comfort cooling and has more than 50 poundsof charge, use the 15 percent leak rate. (If thiswere a commercial refrigerant system, the 35 per-cent leak rate would apply. )

Service Records

Service Dates Refrigerant AddedCalendar Date Julian Date1 October 274 10 lb4 December 338 15 lb

1. Determine the EPA Maximum Leak Rate(EPAMLR):

EPAMLR = 800 lb x 15%/yr = 120 lb/yr

(This is the maximum amount of refrigerantthis unit can lose in a 12-month periodwithout violating the EPA regulation.)

2. Determine the actual leak rate (ALR):

ALR = lb refrigerant added since last servicing(Days between servicing)/(365 days/yr)

ALR = 15 lb of CFC-12(338-274 days)/(365 days/yr)

ALR = 85 lb/yr

3. Is ALR > EPAMLR?

85 lb/yr is less than 120 lb/yr

Action is NOT necessary. However, the unitdid use 15 pounds of refrigerant. Good con-servation practice recommends performing aleak check and repairing the leak.

If the ALR had been > EPAMLR, then theequipment would have to be repaired in 30 daysor a plan developed within 30 days to retire theunit within 12 months.

2.3 Air Force Requirements

2.3.1 Managing Base RefrigerantsAir Force policy governing the use ofCFC refrigerants has dictated the followingrequirements.

2.3.1.1 An Air Force waiver is requiredto purchase CFC refrigerants.

2.3.1.2 Purchasing new facility air condi-tioning systems that use CFCs is prohibit-ed.

2.3.1.3 Manage the base’s refrigerantinventory so existing equipment can bemaintained until the end of its economiclife.

2.3.1.4 When AC/R equipment is retired,its refrigerant must be recovered for use inthe remaining operational systems.

2.3.1.5 Refrigerant ownership cannotbe sold or transferred outside of theDepartment of Defense (DoD). Transferof excess refrigerant to other bases is

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encouraged and should be coordinatedthrough the Major Command (MAJCOM).If refrigerant is to be turned in to theDefense Logistics Agency (DLA) Refrig-erant Bank, it should first be coordinatedthrough the MAJCOM.

2.4 Training and Certification

All technicians who work with refrigerantmust meet EPA certification requirements.The EPA deadline is 14 November 1994.Training and certification sessions includeimproved maintenance practices, identifi-cation of potential improvements to exist-ing AC/R equipment, and familiarizationwith new equipment. There are two waysthe RM can obtain training and certifica-tion opportunities for technicians.

2.4.1 CerTest ModuleAFCESA Maintenance Directorate and theCivil Engineering School (School) atSheppard AFB, Texas developed a100-page study guide and a CertificationTest (CerTest) module for EPA certifi-cation. All Air Force technicians will beable to review the guide and take thecertification test at their home stations.The School is approved by EPA to certifytechnicians.

2.4.2 Local VendorsThe RM can contract with local vendorsfor refrigeration training and EPA certifi-cation. The RM must verify EPA hasapproved the vendor as a certifying agent.Depending on availability, both Operationsand Maintenance and Pollution PreventionProgram funds can be used for buyingtraining and certification testing.

2.5 BCE Conservation Methods

In considering the base’s conservationeffort, the RM should take into accountleak detection, AC/R equipment modifica-tion, and secure storage areas for refriger-ant.

2.5.1 Leak DetectionThe RM should develop a leak detectionprogram that matches each piece of AC/Requipment with a specific type of leakdetection. The RM should also develop anequipment leak check schedule based onthe type of equipment and its past leakhistory. The greater the equipment’s histo-ry of leaks, the more frequently it shouldbe checked.

2.5.1.1 Leak detection procedures varyfrom soap bubbles to sophisticated sensors.Some of the leak detection equipmentitems qualify for Pollution PreventionFunds. For detailed information, reviewAppendix D, Refrigerant Leak DetectionMethods and Equipment; Appendix F,Refrigerant Leak Mitigation throughEquipment Maintenance and Service Prac-tices; and Appendix I, Funding Alterna-tives for Base Refrigerant ManagementProgram.

2.5.2 AC/R Equipment ModificationsSeveral equipment modifications can beused to prevent excessive amounts ofrefrigerant from escaping into the atmo-sphere. For example, the RM shouldidentify all requirements for high-efficien-cy purge units and pressurization systemsfor low-pressure equipment. More infor-mation is available in Appendix E.

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Chapter 2 — Conservation Efforts for the Base Refrigerate Management Program

Pollution prevention funds can provide aresource to pay for equipment modifica-tions (see Appendix I).

2.5.3 WIMS Refrigerant ManagementSoftware

To develop a successful conservationeffort, the RM must control refrigerantwhen it is not in equipment and identifyequipment exceeding the EPA maximumleak rate. To help the RM with refrigerantand equipment control, AFCESA devel-oped the WIMS Refrigerant ManagementSoftware. Appendix G covers the subjectextensively. The software files contain allthe data for the base’s AC/R equipmentand refrigerant inventory. With regularinput of equipment service records andinventory transactions into WIMS softwarefiles, the RIM can generate reports showing

which pieces of equipment are not incompliance and the amount of refrigerantin storage. Regular data entry will satisfythe EPA recordkeeping requirement.

2.5.4 Secure Storage AreasBecause refrigerant is a valuable and di-minishing resource, the base should haveone or more secure storage areas. Me-chanical rooms do not qualify. The RMshould establish storage location(s) basedon ease of accessibility for technicians andpositive control of the resource. This couldmean designating one or more people to beresponsible for the distribution and ac-counting of the refrigerant. For informa-tion on storage room construction stan-dards see Appendix C, Refrigerant StorageRecommendations and Requirements.

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Chapter 3 — Refrigerant Management Plan Development


3.1 Introduction

This chapter describes how to develop anRMP for all AC/R equipment which useregulated refrigerants. A plan should firstbe developed for managing equipmentwhich use CFC refrigerants because CFCproduction will cease in January 1996.Eventually, an RMP needs to be developedfor all equipment containing regulatedrefrigerants. Appendix H, AC/R EquipmentSurvey Guide and Equipment Data Collec-tion Survey Forms, is integral to thedevelopment of the RMP.

3.2 RMP DevelopmentProcedures

The RMP development begins with athorough physical survey and assessmentof the condition of all equipment. Fromthe survey and assessment, a prioritizedEquipment Retirement Schedule (Schedule)is developed. This Schedule is combinedwith refrigerant consumption rates into atimeline forecasting the base’s refrigerantinventory and possible mission impacts asthe retirement schedule is implemented.Next, a funding chart is developed show-ing all the retirement projects’ costs byfiscal year. After completion of a fundsdistribution analysis, an implementationschedule is created to show all requiredRMP actions.

3.3 RMP Products

The seven main products in the RMP arethe:● Equipment List,● Equipment Assessment Table,● Equipment Retirement Schedule,● Refrigerant Inventory Timeline,● Project List,● Funding Chart, and● Implementation Schedule.Together these products give the totalpicture of how refrigerants are managed atthe base by showing all equipment retire-ments, what they cost, when more refrig-erant will be needed, and increases ofrefrigerant inventory by recovery, purchas-es, or interbase transfers. They highlightthe effects of conservation efforts on therefrigerant consumption rates.

3.4 Metrics

The RM can use the RMP to brief theBCE and staff on the status of the BRMP.The RMP details whether retirementschedules are on track and whether refrig-erant inventories are adequate. The RMPshows the big picture and aids the BCE indeciding proper use of base resources. Theinformation in the RMP can be the basisfor funds justifications for equipmentretirement projects and waivers for CFCpurchases.

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3.5 Step 1: Equipment Survey

The RM can begin the initial survey byidentifying on a base map the locations ofall CFC equipment containing more than50 pounds of refrigerant. Using this map,the RM establishes an inspection sequence.The map should also show where centralplants may replace existing individualunits. A method to identify possible centralplant locations is in Appendix H, sectionH. 3.4. The personnel accomplishing thesurvey should have a working knowledgeof the major components of AC/R and leakdetection equipment, understand the pur-pose of the BRMP, and how to use thesurvey forms. It will take approximatelyan hour to survey each piece of equipment.Most leak detection can be done at thetime of the survey. Normally, the onlyequipment the surveyor will need is aportable leak detector. Information onthese devices is in Appendix D, Refriger-ant Leak Detection Methods and Equip-ment. Included in Appendix H is a utilityrate information form. This form shouldbe filled out initially and used to performlife-cycle cost analyses (LCC).

3.5.1 Survey ResultsThe survey results can be used to:● complete the RMP;● request a retrofit analysis from original

equipment manufacturer (OEM);● estimate the cost of an equipment

retirement project;● identify potential locations for a central

chilled water plant;● estimate the cost for complying with

ASHRAE 15-1994;● identify refrigerant leaks and equip-

ment conservation modifications:

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● provide a data base for the WIMSrefrigerant management soft ware; and

● compute the LCC analysis for equip-ment replacements.

3.6 Step 2: Equipment List

The RM uses the data from the equipmentsurvey to develop an Equipment List byrefrigerant. Figure 3-1, Sample CompletedEquipment List, demonstrates how datagathered in the Equipment Survey are usedto develop the Equipment List. The bestway to develop this list and other chartsand graphs in the RMP is with a computersoftware program with spreadsheet andgraphics capabilities. Software programsused to develop the examples in this bookwere Lotus® 1-2-3 and Lotus® FreelanceGraphics.

3.6.1 Equipment List CompletionInformation for columns A, B, C, D, E,and F (Figure 3-1) comes from the equip-ment survey forms (ESF) and data fromWIMS Refrigerant Management Software.To designate the manufacturer in columnC, it may be necessary to assign a “letter.”For example, “Y” is for York, “T” is forTRANE, and “C” is for Carrier. Theequipment capacity and operating charge,columns E and F respectively, are obtainedfrom the equipment nameplate or themanufacturer, if a model or serial numberis known. Columns G and H are the EPAmaximum leak rate for one year in bothpercentage and pounds of refrigerant. Forcolumn G, if the equipment is used forcommercial refrigeration, use 35 percent,and for all others (for example, comfortcooling) use 15 percent. The pounds per

Figure 3-1. Sample Completed Equipment List


year in column H are determined by multi-plying the total charge in a particular unit,column F, by the percentage in column G.Columns I, J, and K determine energyefficiency. Full load amps (FLA) and voltsare shown on the equipment. The efficien-cy, if not listed on the equipment, can beobtained from the equipment manufacturer,the original submittal data, or by calcula-tion (see key at the bottom of Figure 3-l).The power factor can vary from 0.80 to0.95, depending on motor size, type, andmanufacturer or National Electric Manu-facturers Association (NEMA) standards.Column L, Equipment Age, is obtainedfrom base records showing installation dateor from the “manufactured date” found onthe equipment.

3.7 Step 3: EquipmentAssessment Table

The Equipment Assessment Table is usedto determine the priorities for equipmentretirements. Columns A, B, C, and D arerepeated from the Equipment List. Col-umns M, N, O, P, Q, and R are deter-mined by selecting the value which corre-sponds to the range found in “AssessmentRanges and Values” at the bottom ofFigure 3-2, Sample Completed EquipmentAssessment Table. Column S is the sum ofthe values in all the columns for eachpiece of equipment. Column T values arethe priorities of equipment replacementsafter factoring in subjective considerations.

3.7.1 Value DeterminationsTo determine values for columns M, N,O, and P of the Equipment AssessmentTable use data found in the EquipmentList, the ESFs, or the WIMS Refrigerant

Management Software Reports. Column Pvalues are either “0” for minor leaks or“5” for major leaks. A leak is consideredminor if it requires a small amount of timeand funds to repair (such as tighteningloose connections or installing a pressurerelief valve (PRV) and high-efficiencypurge). Even if the machine had a signifi-cant refrigerant loss, it is considered aminor leak because the repair is inexpen-sive. A leak is considered major if it re-quires a large expenditure of funds andlabor to repair (such as a casing leak ortube bundle replacement). The actualamount of refrigerant lost may not neces-sarily be large, but the repair is expensive.This information should be on the ESFsand can be verified by technicians familiarwith the equipment. Column R of theEquipment Assessment Table is either “O”for no overhaul required or “5” for over-haul required in less than three years.Column S of the table is the total of all theother columns and indicates retirementpriorities based on objective reasons. Thehigher the number, the sooner the unitshould be replaced. The rating increases asthe equipment becomes older, less effi-cient, and larger. This reinforces the strat-egies of not retiring the equipment untilthe end of its life expectancy and eliminat-ing the least energy-efficient equipmentfirst.

3.7.2 Subjective ConsiderationsThe RM must consider subjective, as wellas objective, criteria to determine theorder in which to retire equipment. Somesubjective considerations include:● equipment already scheduled for retire-

ment because it is under contract or indesign,

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Chanter 3 — Refrigerant Management Plan Development

Figure 3-2. Sample Completed Equipment Assessment Table

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● number of units scheduled for replace-ment at the same time by a centralplant,

● equipment, neither old nor large, witha major leak, and

● other local factors.Column T of the Equipment AssessmentTable. incorporates the values in column S,revised by the subjective considerations.

3.7.3 Method of ReplacementAt this stage in the RMP, a preliminarydecision should be made on how to retirethe equipment: by retrofitting the existingunit with different refrigerant, by replacingthe unit, or with a central plant? Thisprogramming decision will be refinedduring the RMP implementation processdescribed in Chapter 4, Refrigerant Man-agement Plan Implementation. Informationfrom the WIMS database can help makethis decision along with the followinggeneral guidelines:

● replace a unit over 15 years old,● retrofit a unit which is less than 15

years old during overhaul or majorrepair,

● retrofit a unit● replace a unit● replace a unit

ciency, and● replace a unit

that has excess capacity,that is undersized,with a very poor effi-

with a history of fre-quent maintenance.

3.8 Step 4: EquipmentRetirement Scheduleand RefrigerantInventory Timeline

Developing the Schedule and RefrigerantInventory Timeline (Timeline) for each

refrigerant gives the RM a completepicture of the BRMP. The Schedule(Figure 3-3, Sample Completed EquipmentRetirement Schedule) shows all the activi-ties that cause the refrigerant inventoryto fluctuate with time. The Timeline(Figure 3-4, Sample Completed RefrigerantInventory Timeline) shows the anticipatedinventory as a result of the retirementschedule.

3.8.1 Definition of TermsTo complete the schedule, several termsmust first be defined.

3.8.1.1 The total installed charge (TIC) isthe operating charge, in pounds, for allequipment having the same refrigerant.The initial TIC is the total in column F ofthe Equipment List. As each piece ofequipment is retired, the TIC is recalculat-ed by deducting the retired unit’s refriger-ant charge from the previous TIC,

3.8.1.2 The total EPA maximum leak rate(total EPAMLR) is the total of column Hof the Equipment List. The total EPAMLRis the summation of all the individualequipment’s EPA maximum leak rates,measured in pounds per year. As equip-ment is retired, the total EPAMLR isreduced by the retired equipment’s individ-ual EPAMLR. The individual EPAMLR isfound in column H of the Equipment List.

3.8.1.3 The critical refrigerant reserve(CRR) is the number of pounds of refrig-erant in the piece of equipment with thelargest refrigerant charge for each type ofrefrigerant. When the piece of equipment

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Figure 3-3. Sample Completed Equipment Retirement Schedule


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2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014Fiscal Year

Figure 3-4. Sample Completed Refrigerant Inventory Timeline (continued)

Chapter 3 – Refrigerant Management Plan Development

with the largest operating charge is retired,the CRR decreases to the quantity of re-frigerant in the remaining unit with thelargest operating charge. If the base doesnot have more refrigerant than the CRR inits inventory, the base cannot handle acatastrophic refrigerant loss in this piece ofequipment.

3.8.1.4 The marginal refrigerant reserve(MRR) is the summation of the charge inthe piece of equipment with the largestoperating charge (the CRR) and the totalEPAMLR for that particular refrigerant. Ifthe refrigerant’s inventory quantity goesbelow the MRR, the base must take action,within a year, to prevent the inventoryfrom going below the CRR. The MRR isstated in pounds of refrigerant and equalsthe amount of refrigerant the base needs tohandle a catastrophic refrigerant leak inthe equipment with the largest operatingcharge plus operate all the units at themaximum EPA leak rate for one year. Theinitial MRR equals the initial CRR plus theinitial total EPAMLR. Each time a unit isretired the MRR must be recalculated:1)

2)

3)

Determine if the retired unit has thelargest operating charge. If so, recal-culate the CRR.Reduce the total EPAMLR by theindividual EPAMLR charge of theretired unit.CRR + total EPAMLR = MRR

3.8.1.5 Consumption rate (CR) is theaverage amount of a specific refrigerant,in pounds per year, the base is using tomaintain its equipment for one year. TheCR is found by using the ConsumptionReport in the WIMS Refrigerant Manage-ment Software or by calculations using

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historical refrigerant purchases. The Mate-rial Acquisition Element can provide theamount of refrigerant purchased over aspecific period of time. If 500 pounds ofCFC-12 were purchased in FY93 and thereare 100 pounds in shop inventory, then itcould be assumed that 400 pounds ofCFC-12 were used in FY93 for a 400pounds/year CR. If 300 poundsofCFC-11were purchased in the first three months ofFY94 and 100 pounds are in inventory, itcould be assumed that 200 pounds wereused in three months, for an 800pounds/year CR.

3.8.2 Developing the EquipmentRetirement Schedule

The Equipment Retirement Schedule,Figure 3-3, is developed using the samespreadsheet software used for the Equip-ment List and Equipment AssessmentTable. Abbreviated definitions of thevalues in each column are listed at thebottom of Figure 3-3.

3.8.2.1 Column A (Activities) lists theactivities that cause increases and decreas-es of inventory for a specific refrigerant;column B (Fiscal Year) lists the elapsedtime for each. Column B is the totalelapsed time, in fiscal years, from the startof the Equipment Retirement Schedule tothe completion of a specific activity. It isthe cumulative time, not the time betweeneach activity. Each increase and decreaseto the refrigerant inventory must be shownas an activity. The increases can includeconservation efforts reducing the CR,interbase refrigerant transfers, refrigerantpurchases, and equipment retirements. Thedecreases can be “operational refrigerantconsumption” occurring between


implementation of other activities andinventory transfers to another base.

3.8.2.1.1 Activities are listed in chro-nological order. The frost activity, theinitial refrigerant inventory, is used only atthe beginning of the schedule. Its elapsedtime is always listed as the quarter andfiscal year nearest the date the inventory isdetermined. The next activity in the exam-ple is repairing the leaks found during theequipment survey. This activity may alsoinclude the completion of technician train-ing and EPA certification and establish-ment of equipment monitoring through theWIMS Refrigerant Management Software.For this activity example, elapsed time isestimated at three months (0.25 years). InFigure 3-3, the next reduction in refriger-ant consumption occurs as a result of largerepairs or modifications to equipment; esti-mated to take six months (0.5 years).(Repairs and modifications must be accom-plished as quickly as possible to reduceCR and support the base mission withoutthe need for an outside source of refriger-ant. Each base must strive for self-suffi-ciency.) The example entry, "HospitalEquipment Refrigerant Recycle 1600#,"represents the addition of refrigerant to theinventory due to a retirement of equip-ment. Other activities could include pur-chasing additional refrigerant or receivinga transfer from another base. These activi-ties are base-specific and determined bythe RM. All the equipment retirementactivities in the example can be found incolumn T of Figure 3-2.

3.8.2.1.2 The “operational refrigerantconsumption” activity represents theamount of refrigerant consumed by

equipment operations and maintenance.The amount of consumed refrigerant isbased on the CR. It is very important tounderstand that the completion of a specif-ic activity is when the refrigerant is addedto or subtracted from the inventory and notnecessarily when the activity starts.

3.8.2.2 The values in column C (Equip-ment Operating Charge) are input manual-ly and found in the Equipment List. TheTotal Installed Charge, column D, islowered each time an equipment retirementoccurs. The CR represents the annualizedrefrigerant consumption. Initially, the CR,column E (Consumption Rate), is based onhistorical data. All other entries are pro-jections determined by the RM. The exam-ple shows 9136 pounds per year as thefirst entry in column E. This amount wasdetermined by reviewing the amounts ofrefrigerant purchased by the BCE for theprevious year. The next amount, 4702pounds per year, represents the result of adecrease in consumption over a three-month period as the units are leak testedand identified repairs completed. It is aprojection by the RM based upon achiev-ing an annual consumption rate equal tothe total EPAMLR. The next number,2284 pounds per year, is the new con-sumption rate projection after all purgeunits are installed. Both activities representa base’s initial conservation effort.

3.8.2.2.1 It is assumed the continuingconservation efforts achieve a consumptionrate equal to the total EPAMLR. The AirForce goal is to achieve a near-zero con-sumption rate. Because the purpose of theRMP is to forecast future refrigerant re-quirements in support of the Air Force

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mission, a conservative approach is takenby using the total EPAMLR. Reductions in the CR in relation to the total EPAMLRwill result in increased refrigerant re-serves. The Handbook example shows theCR decreasing to 2015 pounds per yearwhich is the total EPAMLR for all equip-ment using this type of refrigerant.

3.8.2.3 Column F (Inventory Transaction)shows how the base’s refrigerant inventoryis affected by an activity.

3.8.2.4 Column G (Benchstock Refriger-ant Inventory) shows the projected changesin the refrigerant benchstock inventory asthe RMP is implemented. The values aredependent on the time since the last activi-ty (column B), the CR, and the recoveredrefrigerant amounts listed in column F.The first entry is the amount of refrigerantstored on base at the start of the RMP.This is all the refrigerant under the BCE’scontrol and in Base Supply that the BCEcould purchase. It should not include therefrigerant in the operating equipment,TIC, or any refrigerant represented by AirForce-approved waiver authority but notyet purchased. All entries after the firstone are determined by the equation shownon the bottom of Figure 3-3.

3.8.2.5 Column H (Critical RefrigerantReserve) and column J (Marginal Refriger-ant Reserve) are the CRR and MRR.Column I (Time Until CRR) and column K(Time Until MRR) show the time remain-ing in years before the refrigerant invento-ry reaches either the MRR or the CRR.CRR, the amount of refrigerant needed ininventory to prevent mission impact,changes when the unit with the largest

charge is retired. If the inventory quantitygoes below the MRR, it is a warning tothe RM that, with the estimated CR, re-frigerant supplies will be below the CRR ifreplenishment activities do not occur with-in one year. It decreases as the CRR andthe total EPAMLR decrease. Column I andcolumn K are determined by subtractingeither the CRR or the MRR from theRefrigerant Inventory and dividing by theCR. A negative value shows that the in-ventory quantity is below the MRR orCRR.

3.8.3 Refrigerant Inventory TimelineThe Timeline is a graph that forecastsrefrigerant as a function of time. It takesinto account consumption rates and otheractivities which effect the amount ofrefrigerant in benchstock and projectsfuture levels. The Timeline graphicallyrepresents refrigerant conservation effortsand levels of refrigerant to meet missionrequirements. By using a graph, it is easierto see if adequate refrigerant supplies willbe maintained over the remaining life ofexisting equipment. Because much of thebase conservation actions will be takenearly in the RMP, the first six years of theTimeline should be broken into quartersto depict more detail, as shown inFigure 3-4.

3.8.3.1 The Timeline is plotted frominformation found on the Equipment Re-tirement Schedule. The Elapsed Time(column B) is the x-axis and the Refriger-ant Inventory (column G), the y-axis. TheTimeline depicts the refrigerant inventorydecreasing and increasing as the activitiesin the Equipment Retirement Schedule arecompleted. The initial value for the

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refrigerant inventory level is the refriger-ant in storage when the RMP is developed.This is the first value in column G of theEquipment Retirement Schedule.

3.8.3.2 In Figure 3-4 refrigerant con-sumption starts high (steep slope), but isreduced through leak repairs and equip-ment modifications. Because the Timelineis being used to forecast refrigerant inven-tory levels, a conservative approach as-sumes the consumption rate will be re-duced to at least the total EPAMLR for allequipment (column H total in the Equip-ment List for each particular refrigerant).The length of time refrigerant invento-ries will last will be increased by strivingto achieve the Air Force goal of reducingrefrigerant consumption to as near zeroas possible. As equipment is retired, theCR should continue to decrease becausethere is less TIC. The CRR line stair-stepsdown each time the unit using the largestcharge is replaced, and the MRR line goesdown every time an equipment retirementoccurs.

3.8.3.3 If the Timeline goes below theCRR, the base cannot replenish the refrig-erant of the piece of equipment with thelargest charge if the machine has a cata-strophic refrigerant loss. The example inFigure 3-4 took several iterations to com-plete. The activities in the EquipmentRetirement Schedule must be organized sothe Timeline never goes below the CRR.To prevent this from happening, changethe Equipment Retirement Schedule byusing the following actions, in prioritysequence:● increase conservation efforts to reduce

the CR by taking less time to complete

an activity or scheduling more activi-ties in an earlier time frame,

● obtain additional refrigerant inventorythrough purchase or interbase transfer,and

● change the Equipment RetirementSchedule (least desirable becauseequipment should not be retired beforethe end of its economic life).

3.8.3.4 When the Timeline goes belowthe MRR, it is a visual warning the basemust implement its plan to put more re-frigerant back into its inventory or reduceits CR before the CRR is reached. TheEquipment Retirement Schedule does notrequire revision if activities are scheduledto keep refrigerant inventory above theCRR. If those activities are not scheduled,the Equipment Retirement Schedule mustbe changed. Use the same actionsrecommended in the previous paragraph.

3.8.3.5 The Timeline can be used toclearly depict actual conservation efforts.Plot a point, on the Timeline, showingcurrent time and actual consumption rates.Compare this point to the projected point.If the actual point on the Timeline is on orabove the projected point on the Timeline,the BRMP is not behind schedule. If theactual point is below the projected point,management must take steps to adjust.

3.9 Step 5: Project List andFunding Bar Chart

The Project List shows the equipment tobe retired (from the Equipment RetirementSchedule); the Funding Bar Chart shows

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how much the retirements will cost, byfiscal year.

3.9.1 Project ListDevelop the Project List (Figure 3-5,Sample Completed Project List) for eachrefrigerant. The Project List includes thebuilding and unit number, capacity,charge, current age, design and construc-tion costs, and date of retirement. Theequipment retired as the result of installinga chilled water plant should be highlightedso they can be kept together. The pro-gramming cost estimates are based onreplacing equipment with new equipmentidentical in type and capacity. Allowingfor the highest-cost option provides aconservative estimate. Equipment costs canbe obtained from an equipment manufac-turer or by employing a commercial costestimating manual or software program.To arrive at a construction cost, increasethe equipment estimate by 75 percent forremoval and the installation costs. Basedon the information in the equipment surveyforms, this percentage can be adjusted.Add $5,000 to $10,000 for upgradingequipment rooms to ASHRAE 15-1994.This range can be narrowed with informa-tion from the equipment survey forms. Tenpercent of the construction cost should beused for the design cost estimate to includea site study and facility cooling load analy-sis. For all above computations, use localfigures based on local experience if avail-able.

3.9.2 Funding Bar ChartThe Funding Bar Chart depicts all CFCrefrigerants, as shown in Figure 3-6,Sample Completed Funding Bar Chart.

3.9.3 Funding Bar Chart AnalysisThe general goal is to flatten spendingover the full length of the RMP. Theyears with a high funding requirementshould be decreased and the years with alow funding requirement should be in-creased. This can be accomplished bygoing back to the individual EquipmentRetirement Schedules and altering equip-ment retirement dates. The most obviousplace to start is the CFC with the highestfunding requirement in a particular year.The same subjective approach used tocreate a Timeline can also be used todevelop a funding level.

3.10 Step 6: The Implementa-tion Schedule

The Implementation Schedule, shown inFigure 3-7, Sample Completed Implemen-tation Schedule, is developed by combin-ing the information on all the Project Listsfor all CFCs and adding other specifictasks. The Implementation Schedule showsthe milestones needed to ensure projectsare completed by their scheduled dates.Milestones include: cooling load analyses,OEM analyses, design start, bidding peri-od, contract award time, construction start,and construction completion.

3.10.1 Time LengthsWhen creating the Implementation Sched-ule, show the fiscal years (across the top)with the first six years divided into quar-ters to match the Refrigerant InventoryTimeline. Figure 3-7 shows the placementfor the equipment designation, event, andcosts. The data points should be placed onthe chart in reverse order, starting with the

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R- xx PROJECT LISTXYZ AIR FORCE BASE

Survey Date October 6, 1993Project Costs

Equipment Refrigerant Current Design ScheduledBuilding - Unit Capacity Charge Age & Analysis Construction Retirement

Designation (Tons) (Lb) (Years) ($) ($) (End of Qtr & FY)

Hospital 1000 1600 3 0 0 0 2nd Qtr 19947359 525 600 21 0 0 4th Qtr 1994

10056 1000 1200 1 5,000 45,000 2nd Qtr 19955570 280 545 8 18,000 175,000 4th Qtr 19959050 300 635 26 0 0 4th Qtr 19961385 280 545 8 21,500 175,000 2nd Qtr 19979016 260 600 12 21,500 175,000 2nd Qtr 199710416 250 545 8 20,000 145,000 4th Qtr 1997156 150 500 21 13,000 87,500 2nd Qtr 1998

147 -2 125 600 2 13,000 87,500 2nd Qtr 1998115 - 1 259 640 7 7,500 125,000 2nd Qtr 1999115 - 2 259 640 7 7,500 125,000 2nd Qtr 19996418 200 340 3 10,000 150,000 4th Qtr 19999110 250 545 10 26,500 225,000 * 4th Qtr 2001 *9210 280 440 10 26,500 225,000 * 4th Qtr 2001 *9310 280 440 10 26,500 2 2 5 , 0 0 * 4th Qtr 2001 *9410 320 545 10 26,500 225,000 * 4th Qtr 2001 *6275 250 545 10 20,000 136,000 4th Qtr 20049225 320 635 10 23,000 157,000 4th Qtr 20047065 250 525 8 20,000 136,000 4th Qtr 2006146 140 340 2 14,000 98,000 4th Qtr 2011

147 -1 120 340 2 13,000 85,000 4th Qtr 20115616 300 400 2 22,000 152,000 4th Qtr 20125725 290 575 2 22,000 148,000 4th Qtr 20126576 200 340 2 16,000 106,000 4th Qtr 20137246 150 375 2 15,000 103,000 4th Qtr 2013

REFRIGERANT COST TOTALS $408,000 $3,311,000

NOTES:* = Indicates potential Central Chilled Water Plant

Figure 3-5. Sample Completed Project List

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Figure 3-7. Sample Completed Implementation Schedule

Chanter 3 — Refrigerant Management Plan Development

date of retirement obtained from the Pro-ject List. This is the date when refrigerantis available for placing into inventory. Theduration of the required tasks projected foreach installation must be carefully consid-ered. Depending on the required analysesand funding source, several years may beneeded to accomplish all the tasks neces-sary to retire a machine. OEM analysestake four to eight weeks. Expect singleinstallation cooling load analyses to requirethree months and central chiller plantanalyses, six to nine months. These timesare dependent on quantity, type, and sizeof served facilities. Design time estimatesare six months for single installations and

12 months for central plants. Allow sixmonths for bidding and contract awardwith a construction time of 12 months fora single installation and 18 to 24 monthsfor a chiller plant. These numbers are onlyestimates and local estimates should beused if available.

3.11 Step 7: The RMP

With the completion of the ImplementationSchedule, the RMP development is com-plete. Figure 3-8, Sample Tale of Con-tents, provides the RM with an outline touse in organizing the RMP.

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Title PageIncludes title of plan, base name, date, and preparer’s name, office symbol, andphone number.

Executive SummaryOne page detailing the highlights of the RMP. This could include how much moneyover how many years the RMP will take and whether any significant problems are leftunresolved requiring senior-level action.

Base Refrigerant Management Program ReviewGives a verbal picture of the RMP. Describes in more detail some of the itemsdiscussed in the Executive Summary. Should include the base’s ability to execute theplan, funding requirements, number of projects required, and other pertinent informa-tion. Gives an overview of the plan’s organization, describing what each sectionaddresses. Use descriptions from the Handbook to show the compatibility between thebase’s conservation efforts and the RMP. The RMP cannot be accomplished without asolid refrigerant conservation effort and vice versa.

1.2.3.4.5.6.7.

Funding Bar Chart for all CFCs

Implementation Schedule

RMP for R-xxExplanation of RMP Products for R-xxR-xx Project ListR-xx Refrigerant Inventory TimelineR-xx Equipment Retirement ScheduleR-xx Equipment Assessment TableR-xx Equipment ListEquipment Survey Forms should be in same sequence as Equipment List. Include:a) base map showing existing unit and potential plant locationsb) Utility Rates Data sheet

RMP for R-xxx(Repeat same outline as R-xx for remaining refrigerants.)

Figure 3-8. Sample Table of Contents

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Chapter 4 — Refrigerant Management Plan Implementation


4.1 The Philosophy

The CFC RMP is not complete until thelast piece of CFC equipment is retired andits refrigerant is in a storage cylinder.RMP implementation needs the rightsystems and money to pay for them.

4.2 Overview of SystemSelection

System selection is accomplished by:● examining the cooling load profile,● determining whether the existing sys-

tem should be retrofitted or replaced,● choosing the best replacement or retro-

fit option,● assessing the potential to combine two

or more systems into one plant, and● evaluating the cost-effectiveness of

employing heat recovery or thermalstorage technologies.

These analyses are described in the Appen-dices:

K, AC/R Energy Conservation Devices;L, Fundamentals of Cooling Load andEnergy Analysis;M, Evaluating Water Chillers for Re-placement or Retrofit Potential;N, Chiller Selection Guide;O, Assessing the Potential of CentralChilled Water Plants;P, Heat Recovery Alternatives forRefrigerant Chillers; andQ, Assessing the Potential of ThermalEnergy Storage.

4.3 System Selection

The system selection process provides ascope of work, preliminary equipmentselection, and a design and constructioncost estimate. There are five main steps tofinding the right system.

4.3.1 Step 1: Cooling Load AnalysisThe frost step is the cooling load analysis,which verifies the facility’s current coolingload requirement and determines the cool-ing load profile. The cooling load resultscan be used to optimize the retrofit alterna-tive or to correctly size the replacementunit. The load profile is used to optimizeequipment selection and to provide theestimate for annual energy consumption(used in determining LCC for each alterna-tive). Review Appendix L for load analysisprocedures.

4.3.2 Step 2: Retrofit vs ReplacementThe second step is to decide betweenretrofit or replacement. Some of the deci-sion factors are age, capacity versus cool-ing load, mechanical condition, operatingefficiency, and criticality to the facility theunit serves. These alternatives are com-pared over a 20-year study period. Thealternative with the least LCC is chosenfor further development. The proceduresare in Appendix M.

4.3.3 Step 3: Replacement UnitSelection

If the decision is a replacement unit, thethird step is to decide on a specific

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replacement unit. Appendix N uses unitefficiency, fuel source, load matching,initial cost, and annual operating cost todetermine the correct system.

4.3.4 Step 4: Installing a Central PlantAfter steps two and three are complete forall equipment, step four determines ifvarious sets of individual units can bereplaced with a central plant. Potentiallocations for these central plants wereidentified during the equipment survey.The central plant load profile is generatedby combining the profiles of the previouslycalculated loads for the separate systems.A design concept and cost estimate isprepared for the central plant with perfor-mance characteristics and costs obtainedfrom the manufacturer. A 20-year LCCanalysis is performed comparing the cen-tral plant against the combination of all theseparate system alternatives as determinedin steps two and three. The advantage of acentral plant is reduced LCCs due to lowerinitial installation and daily operating costscompared to the sum of the individualunits. If the central plant is the favoredoption, the Equipment Retirement Sched-ule should be reviewed for possible chang-es to the Refrigerant Timeline, ProjectList, Funding Chart, and ImplementationSchedule. The project will probablyrequire Military Construction Program(MILCON) funds that take longer toprogram, authorize, and appropriate.Appendix O details these procedures.

4.3.5 Step 5: Heat Recovery andThermal Storage Technologies

In step five, the effectiveness of using heatrecovery and thermal storage technologies

on the final equipment replacement choicesis evaluated. Appendices P and Q detailthese procedures. If local conditions arefavorable to one or both options, thenLCC analysis should be used to select thebest approach.

4.4 System Selection Resources

4.4.1 PersonnelThe personnel required to accomplish thesystem selections must be engineers withan understanding of design and operationsof chilled water systems, energy analysisof building mechanical systems, and eco-nomic evaluations.

4.4.2 TimeThe effort required to perform these tasksvaries considerably, based upon systemand installation. The following time esti-mates illustrate how complicated some ofthese analyses are:● cooling load analysis of one building -

80 hours;● retrofit versus replacement analysis -

40 hours (does not include up to sixweeks to receive information fromOEM);

● central plant analysis to replace singleunits -160 hours (includes cooling loadanalysis; may require more hours ifprevious individual facility load pro-files do not already exist);

● heat recovery analysis -80 hours(if cooling load analysis is com-plete); and

● thermal storage analysis -120 hours(if cooling load analysis is com-plete)

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4.4.3 Technical ReferencesTechnical literature needed to completesystem selection includes all the referencescited in this Handbook, local documents,and, if desired, computer software.

4.5 Importance of FundingThe availability of funds is very importantto the completion of the RMP. The RMPproducts should be used as the basis forfunding justifications. There are fivesources of funds for projects identified in

the RMP: Operations and Maintenance(O&M), Military Construction Program(MILCON), Energy Conservation Invest-ment Program (ECIP), Federal EnergyManagement Program (FEMP), and Pollu-tion Prevention Program (PPP) funds.ECIP, FEMP, and PPP funds have specialcriteria that are not as widely known asO&M and MILCON. Appendix I is adetailed description of these three fundsincluding definitions, criteria, and exam-ples of project justifications.

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Appendix A — Update on Refrigerants: Translating the Laws, Regulations, and Policies into Practice

Appendix A — Update on Refrigerants:Translating the Laws, Regulations, and Policies into Practice

ABSTRACT: This appendix details the policies which effect the use of ozone-depletingchemicals (ODCs) and, in particular, refrigerants. It covers the Montreal Protocol, federaltaxes, the Clean Air Act Amendments (CAAA), Environmental Protection Agency’s (EPA) rulesand regulations, and Air Force policy directives.

A.1 The Montreal Protocol

Since 1974, atmospheric scientists world-wide have substantiated and refined thehypothesis confirming the long-term,negative consequences of chlorofluoro-carbon (CFC) use. In response to thescientists’ concerns, representatives of 35nations met in 1987 at the United NationsEnvironment Programme (UNEP) in Mon-treal and established an international proto-col for restricting CFC and halon produc-tion. Representatives from 93 nations metin London in 1990 to revise the Protocolin light of new information on ozonedestruction. This meeting resulted in anaccelerated CFC phase-out schedule. Co-penhagen was the site of UNEP’s Novem-ber 1992 meeting with the outcome takingthe form of accelerated phase-out sched-ules.

A.1.l Phase-Out SchedulesThe 1992 UNEP meeting accelerated theCFC phase-out schedule from the MontrealProtocol and included a phase-out schedulefor hydrochlorofluorocarbons (HCFCS).CFC production must cease by January1996 and HCFC production must be downto 0.5 percent of 1989 levels by 2020,with total production stoppage by 2030.

Specifically, the HCFC-22 phase-out datefor use in new equipment is 2010 and2020 for full production ban. HCFC-123will stay in production until 2030. Thereason for the special consideration forHCFC-123 is because of its low ozone-depletion potential (ODP) and short atmo-spheric lifetime (less than two years).

A.1.2 Applicable CFCsThe CFC refrigerants used by the AirForce for air conditioning and refrigeration(AC/R) and affected by the Protocol areCFC-11, CFC-12, CFC-113, CFC-500,CFC-501, CFC-502, and CFC-503.

A.1.3 Applicable HCFCsThe HCFC refrigerants affected by theProtocol are HCFC-22 and HCFC-123.

A.2 Taxes

A.2.1 Federal Excise TaxThe Omnibus Budget Reconciliation Act of1989 imposed an excise tax on certainODCs and imports of products made withor containing such chemicals. The tax,which was increased in late 1992, wasdesigned to penalize consumers of ODCsand bring the prices of these chemicalscloser to those of the new alternatives. The

A-1

Appendix A – Update on Refrigerants: Translating the Laws, Regulations, and Policies into Practice

tax, applied only to new refrigerant, isdetermined by multiplying each chemical’sODP by the base tax rate. The base taxper pound started at $1.37 in 1991 andincreases to $7.15 by 1999. The Air Forcestarted in June 1993 to significantly restrictthe purchase of refrigerant. This excise taxwill have negligible effects on Air ForceAC/R operations.

A.2.2 Floor Stocks TaxODCs are subject to a floor stocks tax thatare held for sale or use in further manufac-ture on the date the tax is imposed. Thistax is not applicable to Air Force opera-tions. An ODC that is held by a govern-ment for its own use is not held for saleeven if the ODC will be transferred be-tween agencies or other subdivisions thathave or are required to have differentemployer identification numbers.

A.3 Clean Air Act Amendments(CAAA)

The CAAA was passed in November1990. CAAA, Title VI, Section 608 of thatlaw established national goals for thereduction and elimination of stratosphericozone-depleting substances. It bannedproduction of CFCs by the year 2000,established a production cessation date of2030 for HCFCs, and required EPA toestablish dates and requirements prohibit-ing venting of CFCs during servicing. InFebruary 1992, 11 months before theCopenhagen meeting of the Protocol, thePresident of the United States issued anOrder to ban production of CFC refriger-ants after December 1995. The Ordercalled for reevaluation and possibly mov-ing up the production ban for HCFCs.

This Order set the stage for the final re-sults of the Copenhagen meeting that tookplace later that year.

A.4 EPA Regulations

Following is an overview of the refrigerantrecycling requirements of CAAA, Section608. It includes final regulations publishedin the 14 May 1993 Federal Register40 C.F.R. Part 82 (1993) and the prohibi-tion on venting that became effective on 1July 1992. These requirements have adirect impact on the day-to-day activitiesof the base civil engineer (BCE). Foradditional information call the UnitedStates Environmental Protection Agency’sStratospheric Ozone Information Hotline,800-296-1996, from 10:00 am to 4:00 pm,eastern time, Monday through Friday. Theregulations include the following proce-dures.●

●

●

●

●

●

Require service practices that maximizerecycling of ODCs during the servicingand disposal of AC/R equipment.Set certification requirements for recy-cling and recovery equipment, techni-cians, and reclaimers.Restrict the sale of refrigerant to certi-fied technicians.Require persons servicing or disposingof AC/R equipment to certify to EPAthat they have acquired recycling orrecovery equipment and are complyingwith the requirements of the rule.Require the repair of substantial leaksin AC/R equipment with a chargegreater than 50 pounds.Establish safe disposal requirements toensure removal of refrigerants fromgoods that enter the waste stream withthe charge intact (for example, home

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refrigerators and room air condition-ers).

A.4.1 Prohibition on VentingEffective 1 July 1992, the CAAA prohibitsindividuals from knowingly venting ODCsused as refrigerants into the atmospherewhile maintaining, servicing, repairing, ordisposing of AC/R equipment. Only fourtypes of releases are permitted under theprohibition.

A.4.1.1 “De minimis” quantities of re-frigerant released in the course of makinggood faith attempts to recapture and recy-cle or safely dispose of refrigerant.

A.4.1.2 Refrigerants emitted in the courseof normal operation of AC/R equipment(as opposed to the maintenance, servicing,repair, or disposal of this equipment) suchas from mechanical purging and leaks.However, EPA is requiring the repair ofsubstantial leaks.

A.4.1.3 Mixtures of nitrogen and R-22are used as holding charges or as leak testgases, because in these cases the ODC isnot used as a refrigerant. However, atechnician may not avoid recovering re-frigerant by adding nitrogen to a chargedsystem. Before nitrogen is added, thesystem must be evacuated to the appropri-ate level (see Table A-1, Required Levelsof Evacuation for Appliances except forSmall Appliances, MVACs, and MVAC-Like Appliances). Otherwise, the CFC orHCFC vented along with the nitrogen willbe considered a refrigerant. Similarly,pure CFCs or HCFCs released from appli-ances will be presumed to be refrigerants.

Their release will be considered a violationof the prohibition on venting.

A.4.1.4 Small releases of refrigerantresulting from purging hoses or connectingor disconnecting hoses to charge or serviceappliances will not be considered viola-tions of the prohibition on venting. How-ever, recovery and recycling equipment,manufactured after 15 November 1993,must be equipped with low-loss fittings.

A.4.2 Service Practice RequirementsEPA has also established requirementswhich must be met in servicing AC/Requipment.

A.4.2.1 Beginning 13 July 1993, techni-cians are required to evacuate AC/R equip-ment to established vacuum levels. If thetechnician’s recovery or recycling equip-ment is manufactured any time before15 November 1993, the AC/R equipmentmust be evacuated to the levels describedin the first column of Table A-1. Therecovery or recycling equipment must havebeen certified by an EPA-approved equip-ment testing organization (see 40 C.F.R.Part 82 (1993), Subpart F, . 158). Tech-nicians repairing small appliances, such ashousehold refrigerators, household freez-ers, and water coolers, are required torecover 80 to 90 percent of the refrigerantin the system, depending on the status ofthe system’s compressor.

A.4.2.2 EPA has established limitedexceptions to its evacuation requirementsfor repairs to leaky equipment and repairsnot major and not followed by an evacua-tion of the equipment to the environment.

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Table A-1. Required Levels of Evacuation for AppliancesExcept for Small Appliances, MVACS, and MVAC-Like Appliances1

Inches of Mercury Vacuum*Using Equipment Manufactured:

Before On or AfterType of Appliance 15 Nov 1993 15 Nov 1993

HCFC-22 appliance** normally containing less than 200 0 0pounds of refrigerant

HCFC-22 appliance** normally containing 200 pounds 4 10or more of refrigerant

Other high-pressure appliance** normally containing less 4 10than 200 pounds of refrigerant(CFC-12, -500,-502, -144)

Other high-pressure appliance** normally containing 200 4 15pounds or more of refrigerant(CFC-12, -500,-502, -144)

Very high-pressure appliance (CFC-13, -503) o 0

Low-pressure appliance (CFC-11, HCFC-123) 25 29

* Relative to standard atmospheric pressure of 29.9* Hg** Or isolated component of such an appliance1 Federal Register, Vol. 58, No. 52, Friday, May, 1993, pg. 28

If, due to leaks, evacuation to the levels inTable A-1 is not attainable, or wouldsubstantially contaminate the refrigerantbeing recovered, persons opening theappliance must● isolate leaking from non-leaking com-

ponents wherever possible,● evacuate non-leaking components to the

levels shown in Table A-1, and● evacuate leaking components to the

levels that can be attained withoutsubstantially contaminating the refriger-ant ( < O pounds per square inch(psig)).

A.4.2.2.1 If evacuation of the equipmentto the environment is not to be performedwhen repairs are complete, and if therepair is not major, then the appliancemust● be evacuated to at least O psig before it

is opened if it is a high- or very high--pressure appliance; or

● be pressurized to O psig before it isopened if it is a low-pressure appli-ance.

Methods that require subsequent purging(for example, nitrogen) cannot be used.

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A.4.2.2.2 Repairs considered major arethose involving removal of the compres-sor, condenser, evaporator, or auxiliaryheat exchanger coil.

A.4.2.3 EPA has established refrigerantrecovered and/or recycled can be returnedto the same system or other systems ownedby the same person without restriction. Ifrefrigerant changes ownership, however,that refrigerant must be reclaimed (that is,cleaned to the ARI 700-98 standard ofpurity and chemically analyzed to verifythat it meets this standard). This provisionwill expire in May 1995, when it may bereplaced by an off-site recycling standard.(The Air Force believes that refrigerantcan be transferred between bases withouthaving to be reclaimed because the AirForce is a single owner.)

A.4.3 Equipment CertificationThe EPA has established a certificationprogram for recovery and recycling equip-ment. Under the program, EPA requiresthat equipment manufactured on or after15 November 1993 be tested by an EPA-approved testing organization to ensurethat it meets EPA requirements. Recyclingand recovery equipment intended for usewith AC/R equipment, besides small appli-ances, must be tested under the ARI740-93 test protocol. Recovery equipmentintended for use with small appliancesmust be tested under the ARI 740-93 pro-tocol. The EPA is requiring recoveryefficiency standards that vary depending onthe size and type of AC/R equipment beingserviced. For recovery and recyclingequipment intended for use with AC/Requipment besides small appliances, thestandards are the same as those shown in

the second column of Table A-1. Recoveryequipment intended for use with smallappliances must be able to recover 90percent of the refrigerant in the smallappliance when the small appliance com-pressor is operating and 80 percent of therefrigerant in the small appliance when thecompressor is not operating.

A.4.4 Equipment GrandfatheringEquipment manufactured before15 November 1993, including home-madeequipment, will be grandfathered if itmeets the standards in the first column ofTable A-1. Third-party testing is not re-quired for equipment manufactured before15 November 1993 (see Equipment Certifi-cation).

A.4.5 Refrigerant LeaksOwners of equipment with charges ofgreater than 50 pounds are required torepair substantial leaks within 30 days. Ifthe owner does not want to repair theequipment, a retirement plan must be de-veloped in 30 days and will be implement-ed in 12 months. A copy of the plan mustbe available at the equipment location. A35 percent annual leak rate is establishedfor the industrial process and commercialrefrigeration sectors as the trigger forrequiring repairs. An annual leak rate of15 percent of charge per year is estab-lished for comfort cooling equipment andall other equipment with a charge of over50 pounds other than industrial processand commercial refrigeration equipment.Owners must keep records of the quantityof refrigerant added to their equipmentduring servicing and maintenance proce-dures. The Air Force Civil Engineer Sup-port Agency (AFCESA) developed Work

A-5


Information Management System (WIMS)Refrigerant Management Software whichcan accomplish the recordkeeping.

A.4.6 Mandatory TechnicianCertification

The CAAA of 1990, Title VI, Section 608imposes requirements for the training andcertification of technicians involved in themaintenance and service of refrigerationsystems.

A.4.6.1 The EPA has developed fourtypes of certification:

Type I

Type II

Type III

Universal

For servicing small appliances.

For servicing or disposing ofhigh- or very high-pressureappliances, except small appli-ances and MVAC.

For servicing or disposing oflow-pressure appliances.

For servicing all types of equip-ment.

A.4.6.2 Persons removing refrigerantfrom small appliances and MVACs forpurposes of disposal of these appliances donot have to be certified.

A.4.6.3 Technicians are required to passan EPA-approved test given by an EPA-approved certifying organization. Techni-cians must be certified by 14 November1994 to be able to maintain, service, andrepair AC/R equipment.

A.4.6.4 EPA will propose an amendmentto its final recycling rule that would

require technician certification organiza-tions to meet most not all of the require-ments in the final rule. This change isrequired to ensure technicians tested undera voluntary program can be grandfatheredas intended. Up to this time no organiza-tion who has applied for grandfatheringmeets all of the requirements. In order toensure technicians who participated involuntary programs have sufficient time totake any testing that is required pursuant toEPA review, EPA will propose that tech-nicians who participated in voluntaryprograms be given six months after final-ization of the amended rule to becomecertified. To be eligible for this extension,programs would have to apply (or havealready applied) to grandfather technicianswithin 30 days of publication of the finalamendment. EPA will propose that thesetechnicians be permitted to purchase re-frigerant in the interim using the cardsissued to them by the voluntary program.Technicians who have not participated inone of the applying programs must still becertified by 14 November 1994. It isrecommended that those Air Force techni-cians who took voluntary tests contact theorganizations who administered the examand ask if they are applying for grand-fathering. If the organizations are notapplying for grandfathering, then thetechnicians must be certified under anycurrent, EPA-approved program.

A.4.7 Refrigerant Sales RestrictionsAfter 14 November 1994, the sale of re-frigerant in any size container will berestricted to technicians certified by anEPA-approved program.

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A.4.8 Certification by Owners of Re-cycling and Recovery Equipment

EPA is requiring that persons servicing ordisposing of AC/R equipment certify toEPA that they have acquired (built,bought, or leased) recovery or recyclingequipment and that they are complyingwith the applicable requirements of thisrule. This certification must be signed bythe owner of the equipment or anotherresponsible officer and sent to the appro-priate EPA Regional Office by12 August 1993. A sample form for thiscertification is Figure A-1, The UnitedStates Environmental Protection Agency(EPA) Refrigerant Recovery or RecyclingDevice Acquisition Certification Form. Al-though owners of recycling and recoveryequipment are required to list the numberof trucks based at their shops, they do notneed to have a piece of recycling or recov-ery equipment for every truck.

A.4.9 Safe Disposal RequirementsUnder EPA’s rule, equipment that is typi-cally dismantled on-site before disposal(for example, retail food refrigeration,cold storage warehouse refrigeration,chillers, and industrial process refrigera-tion) has to have the refrigerant recoveredin accordance with EPA’s requirements forservicing. However, equipment that typi-cally enters the waste stream with thecharge intact (for example, householdrefrigerators and freezers, room air condi-tioners) is subject to special safe disposalrequirements. Under these requirements,the final person in the disposal chain (forexample, a scrap metal recycler or landfillowner) is responsible for ensuring thatrefrigerant is recovered from equipmentbefore the final disposal of the equipment.

However, persons “up-stream” can removethe refrigerant and provide documentationof its removal to the final person if this ismore cost-effective. The technician certifi-cation is not required for individuals re-moving the refrigerant from appliances inthe waste stream. The disposal require-ments take effect on 13 July 1993.

A.4.10 Major RecordkeepingRequirements

The EPA recordkeeping requirementsdiscussed in A.4.10.1 and A.4.10.2 can bemet by using the WIMS Refrigerant Man-agement Software. For a detailed descrip-tion of this software, see Appendix G,Work Information Management System(WIMS).

A.4.10.1 Technicians servicing appliancesthat contain 50 or more pounds of refriger-ant must provide the owner with an in-voice that indicates the amount of refriger-ant added to the appliance. Techniciansmust also keep a copy of their proof ofcertification at their place of business.

A.4.10.2 Owners of appliances that con-tain 50 or more pounds of refrigerant mustkeep service records documenting the dateand type of service, as well as the quantityof refrigerant added.

A.4.11 Hazardous Waste DisposalEPA has established requirements for thesafe disposal of refrigerants.

A.4.11.1 If refrigerants are recycled orreclaimed, they are not considered hazard-ous under federal law. In addition, usedoils contaminated with CFCs are not

A-7



A-8

Appenddix A — Update on Refrigerants: Translating the Laws, Regulations, and Policies into Practice

THE UNITED STATES ENVIRONMENTAL PROTECTION AGENCY (EPA)REFRIGERATION RECOVERY OR RECYCLING DEVICE

ACQUISITION CERTIFICATION FORM

EPA regulations require establishments that service or dispose of refrigeration or air conditioning equipment to certify

[by 90 days after publication of the final rule] that they have acquired recovery or recycling devices that meet EPA

standards for such devices. To certify that you have acquired equipment, please complete this form according to the

instructions and mail it to the appropriate EPA Regional Office. BOTH THE lNSTRUCTIONS AND MAILING

ADDRESSES CAN BE FOUND ON THE REVERSE SIDE OF THIS FORM.

PART 1: ESTABLISHMENT INFORMATIONName of Establishment Street

(Area Code)Telephone Number City State Zip Code

Number of Service Vehicles Based at Establishment

PART 2: REGULATORY CLASSIFICATION

Identify the type of work performed by the establishment. Check all boxes that apply.

❑ Type A -Service small appliances❑ Type B -Service refrigeration or air conditioning equipment other than small appliances❑ Type C -Disposal of small appliances❑ Type D -Dispose of refrigeration or air conditioning equipment other than small appliances

PART 3: DEVICE IDENTIFICATIONCheck Box if Self-

Name of Device(s) Manufacturer Model Number Year Serial Number (if any) Contained

1 . ❑

2 . ❑

3. ❑

4. ❑

5. ❑

6. ❑

7 . ❑

PART 4: CERTIFICATION SIGNATURE

I certify that the establishment in part 1 has acquired the refrigerant recovery or recycling device(s) Iisted inPart 2, that the establishment is complying with Section 608 regulations, and that the information given is trueand correct.

Signature of Ownership/Responsible Officer Date Name (Please Print) Title

Public reporting burden for the collection of information is estimated to vary from 20 munites per response with an average of 40 minutes per response, including time for reviewing instructions, searching existing

data sources, gathering and maintaining the data needed, and completing the collection of information. Send regarding ONLY the burden estimates or any other aspects of the collection of information,

including suggestions for reducing the burden to Chief, Information Policy Branch, EPA, 401 M St., S. w. (PM-223Y), Washington, DC 20460, and to the Office of Information and Regulatory Affairs. Office of

Management and Budgets, Washington, DC 20503, market 'Attention Desk Officer of EPA'. DO NOT SEND THIS FORM TO THE ABOVE ADDRESS. ONLY SEND COMMENTS TO THESE ADDRESSES.

Figure A-1. The United States Environmental Protection Agency (EPA)Refrigerant Recovery or Recycling Device Acquisition Certification Form

A-9

Appendix A – Update on Refrigerants: Translating the Laws, Regulations, and Policies into practice

lnstructions

Part 1: Please provide the name, address, phone number of theestablishment where the refrigerant recovery or recycling device(s)is (are) located. Please complete one form for each location. Statethe number of vehicles based at this location that are used totransport technicians and equipment to and from service sites.

Part 2: Check appropriate boxes for the type of workperformed by technicians who are employees of the establishment.The term "small appliances" refers to any of the following productsthat are fully manufactured, charged and hermetically sealed in afactory with five pounds or less of refrigerant refrigerators andfreezers designed for home use, room air conditioners (includingwindow air conditioners and packaged terminal air conditions),packaged terminal heat pumps, dehumidifiers, under-the-counterice makers, vending machines and drinking water coolers.

Part3: For each recovery or recycling device acquire, please listthe name of the manufacturer of the device, and (if applicable) itsmodel number end serial number.

If more than 7 devices have been acquired, please fill out anadditional form and attach it to this one. Recovery devices that areself-contained should be listed first and should be identified bychecking the box in the last column on the right. A self-containeddevice is one that uses its own pump or compressor to removerefrigerant from refrigeration or air conditioning equipment. On theother hand, system-dependent recovery devices rely solely uponthe compressor in the refrigeration or air conditioning equipmentand/or on upon the pressure of the refrigerant inside the equipmentto remove the refrigerant inside the equipment to remove therefrigerant.

If the establishment has been listed as Type B and/or TypeD Part 2, then the first device listed in Part 3 must be a self-contained device and identified as such by checking the box in thelast column to the right.

If any of the devices are homemade, they should be identifiedby writing "homemade" in the column provided for listing the nameof the device manufacturer. Homemade devices can be certifiedfor establishments that are listed as Type A or Type B in Part 2 until [six months after promulgation of the rule]. Type C or Type Destablishments can oertify homemade devices at any time. If,however, a Type C or Type D establishment is certifying equipmentafter [six months after promulgation of the rule], then it must notuse these devices for service jobs classified as Type A or Type B.

Part 4: This form must be signed by either the owner of theestablishment or another responsible officer. The person whosigns is certifying that the establishment is complying with Section608 regulations, and that the information provided is true andcorrect.

EPA Regional Offices

Send your form to the EPA office listed below under the stateor territory in which the establishment is located:

Connecticut, Maine, Massachusetts, New Hampshire, RhodeIsland, Vermont

CAA 608 Enforcement Contact: EPA Region 1, Mail CodeAPC, JFK Federal Building, One Congress Street, Boston,MA 02203

New York, New Jersey, Puerto Rico, Virgin Islands

CAA 608 Enforcement Contact: EPA Region II, Jacob K.Javits Federal Building Room 5000,26 Federal Plaza,New York, NY 10278

Delaware, District of Columbia, Maryland, Pennsylvania,Virginia, West Virginia

CAA 608 Enforcement Contact EPA Region Ill, MailCode 3AT21 , 841 Chestnut Building, Philadelphia, PA19107

Alabama, Florida, Georgia, Kentucky, Mississippi, NorthCarolina, South Carolina, Tennessee

CAA 608 Enforcement Contact: EPA Region IV, MailCode APT-AE, 345 Courtland St NE, Atlanta, GA 30365

Illinois, Indiana, Michigan, Minnesota, Ohio, Wisconsin

CAA 608 Enforcement Contact EPA Region V, Mail CodeAT18J, 77 W Jackson Blvd., Chicago, IL 60604

Arkansas, Louisiana, New Mexico, Oklahoma, Taxes

CAA 809 Enforcement Contact: EPA Region Vl, MailCoda ST-EC, First Interstate Tower af Fountain Place,1445 ROSS AVe., Suite 1200, Dallas, TX 75202

lowa, Kansas, Missouri, Nebraska

CAA 608 Enforcement Contact EPA Region Vll, MailCode ARTX/ARBR, 726 Minnesota Ave.. Kansas City, KS66101

Colorado, Montana, North Dakota, South Dakota, Utah,Wyoming

CAA 608 Enforcement Contact: EPA Region VIII, MailCode 8AT-AP, 999 18th Street Suite 500, Denver, CO80202

America Samoa, Arizona, California, Guam, Hawaii, Nevada

CAA 608 Enforcement Contact: EPA Region IX, MailCode A-3, 75 Hawthorne St., San Francisco CA 94105

Alaska, Idaho, Oregon, Washington

CAA 806 Enforcement Contact: EPA Region X, Mail CodeAT-082, 1200 Sixth Ave., Seattle, WA 98101

Figure A-1. The United States Environmental Protection Agency (EPA)Refrigerant Recovery or Recycling Device Acquisition Certification Form (continued)

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hazardous if they are not mixed with otherwaste.● Contaminated oils are subjected to

CFC recycling or reclamation.● Contaminated oils are not mixed with

used oils from other sources.

A.4.11.2 Used oils containing CFCs afterthe CFC reclamation procedure, however,are subject to specification limits for usedoil fuels if these oils are destined forburning.

A.4.12 EnforcementEPA is performing random inspections,responding to tips, and pursuing potentialcases against violators. Under the CAAA,EPA is authorized to assess fines of up to$25,000 per day for any violation of theseregulations.

A.5 Air Force Requirements

Air Force requirements are contained intwo documents: ETL 91-7 and the ActionMemorandum 7 January 1993. These twodocuments make up the major policy andprocedural guidance that AFCESA used todevelop the Base Refrigerant ManagementProgram (BRMP).

A.5.1 ETL 91-7In response to the CAAA of November1990, AFCESA published ETL 91-7. ETL91-7 identified strategies on how to containthe emissions of CFCs and replace refrig-erant in existing AC/R equipment andwhen to change out a piece of AC/Requipment. ETL 91-7 prohibited any futurepurchase of AC/R equipment for HVACinstallations which used CFC-11 orCFC-12 and identified acceptable

alternative refrigerants to includeHCFC-22, HCFC-123, and HFC-134a.Even though two of these alternatives areHCFCs, they are acceptable replacementsbecause the Protocol production ban doesnot affect them until after 2020 and 2030,respectively. This allows sufficient timefor the AC/R equipment containing theseHCFCs to operate to the end of theireconomic life.

A.5.1.1 Existing equipment containingCFCs must be properly operated and main-tained to reduce leaks and emissions dur-ing routine handling, servicing, and over-haul. Base civil engineer (BCE) personnelmust:● use pump-out/recovery equipment,● retrofit low-pressure chillers with

high-efficiency purge systems,● identify and correct leaks,● reclaim contaminated or otherwise

unusable refrigerant,● monitor refrigerant usage, and● institute conservation practices.

A.5.1.2 Retrofitting (conversion) of exist-ing AC/R equipment, typically centrifugalchillers, should be accomplished when it iseconomically or operationally appropriate.An “engineered conversion” should bemade in consultation with the originalequipment manufacturer (OEM). Theydecide the effect on capacity and energyusage. They also determine the properconversion program to minimize degrada-tion in capacity and increased energy con-sumption. Consider supplementing lostcapacity with an additional chiller bycomparing the cost of this approach to thecost of the various conversion options.

A-11


A.5.1.3 AC/R equipment should be re-placed when it● reaches the end of its useful mechani-

cal life and overhaul is not cost-effec-tive,

● can no longer meet mission require-ments, or

● cannot be economically converted tooperate on an alternative refrigerant orconversion is otherwise not cost-effec-tive.

A.5.1.4 ETL 91-7 details how equipmentrooms must be modified in accordancewith ASHRAE 15-1994, when to replaceand use purge and pump-out units, and theappropriate use of absorption equipmentand multiple AC/R units.

A.5.2 Secretary and Chief of Staff ofthe Air Force Action Memoran-dum, Ban on ODC Purchases

Because of the UNEP decision made inlate 1992 to institute a global productionban of CFCs and halons by 1995 and1994, respectively, the Air Force realizedthat operations had to change. The soonerthe Air Force learns to live without thesesubstances the less likely it will suffer amission stoppage and contribute to deple-tion of the earth’s ozone layer. The poli-cies established by the Action Memoran-dum 7 January 1993 apply to all AirForce, Reserve, Air National Guard, andgovernment-owned, contractor-operatedactivities. The Action Memorandum 7 Jan-uary 1993 stressed that the Air Forcecould not allow “business as usual. ” Itestablished the requirement for waivers topurchase new ODCs or receive them fromthe Defense Logistics Agency ODC bankfor mission-critical applications and

directed Air Staff functions to reducedependence on CFCs.

A.5.2.1 The Action Memorandum 7 Janu-ary 1993 laid out specific guidance for allAir Force missions which use CFCs.These included acquisition of facility airconditioning systems, air/ground equip-ment (AGE) and other refrigeration andsupport equipment, and commercial vehi-cles. It tasked the Air Force Civil Engi-neer (AF/CE) to develop installation guid-ance for managing refrigerant inventory soexisting chillers can be maintained untilthe end of their economic life. This includ-ed recovering refrigerant from retiredequipment to service remaining CFCsystems. In general, the Action Memoran-dum 7 January 1993 reinforced the guid-ance contained in ETL 91-7 and was theimpetus behind the development of theBRMP.

A.5.2.2 On 14 July 1993, the AssistantVice Chief of Staff of the Air Force issueda letter detailing the Air Force ODC inter-im waiver application, approval proce-dures, and reporting requirements. Theletter stated that as of 1 June 1993 waiverswere necessary:● prior to award of any contract that

requires the use of a Class I ODC,● to purchase new or recycled ODCs, or● to obtain ODCs from the Defense

Logistics Agency ODC bank for mis-sion-critical applications.

A.5.2.2.1 Using the letter as a guide,AFCESA developed blanket waiver appli-cations for CY93 and 94 that covered allfacility AC/R equipment refrigerant re-quirements for AF/CE activities including

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the Air National Guard and Reserves. Theapplications were approved and AFCESAdistributed the approved quantities to allmajor commands (MAJCOMs).

A.5.2.2.2 An Air Staff approved waiveris required for refrigerant quantities direct-ly related to:● purchase of CFC refrigerants;● maintenance and service contracts

which require contractors to purchase

CFC refrigerants (if the governmentsupplies refrigerant to the contractor,the contract does not require a waiver);and

● purchase of new equipment which usesCFC refrigerants (for example, house-hold refrigerators, ice machines, refrig-erating domestic appliances used in thefamily/unaccompanied housing andlodging facilities, food establishments,medical, and other base facilities).

A-13 (A-14 Blank)


Appendix B — Refrigerant Sensors and Monitoring of Equipment Rooms

Appendix B — Refrigerant Sensors andMonitoring of Equipment Rooms

ABSTRACT: This appendix describes the various refrigerant area monitors available to detectrefrigerants within mechanical rooms and refrigerant storage areas. Information is provided onthe applications of these monitors. Halogen-sensitive detectors are described in the greatestdetail, as they are most appropriate for these applications.

B. 1 Introduction

ETL 91-7 requires all new mechanicalequipment rooms be designed in accor-dance with the most current edition of theASHRAE standard covering the AmericanNational Standard Safety Code for Mech-anical Refrigeration. Right now this isASHRAE Standard 15-1994. ETL 91-7also requires all existing mechanical roomsmust be upgraded to comply with this stan-dard whenever new mechanical equipmentis installed or existing mechanical equip-ment is retrofitted. ASHRAE 15-1994requires the installation of a refrigerantvapor detector for all types of refrigerants.This appendix provides an overview ofthese requirements and an introduction torefrigerant leak detection equipment.

B.2 Refrigerant SensorTerminology

The following terminology and criteriaassociated with refrigerant sensors anddetection allows each type to be compared.These criteria, sensitivity, detection, limits,and selectivity, apply to both portable pin-point detectors and permanently-mountedarea monitors.

B.2.1 SensitivityThe sensitivity of any device is defined asthe amount of input (material beingmeasured) necessary to generate a certainchange in output signal. For refrigerantsensors, the input is the refrigerant vaporconcentration being measured and the out-put is the reading from a panel meter, avoltage output, or other display device.Refrigerant sensors with good (high) sensi-tivity require little material to generate alarge change in output signal. Sensors withpoor (low) sensitivity require largeramounts to change the output signal. Thesensitivity is affected by the method ofdetection and the material being detected.

B.2.1.1 The sensitivity of an ionizationsensor associated with a particular materialthat demonstrates high sensitivity forCFC-12 may have low sensitivity forHCFC-123 and very low sensitivity forHFC-134a. The variations in sensitivityare due to reduction in chlorine content,very easily ionized and detected, fromchlorofluorocarbons (CFC) to hydrochloro-fluorocarbons (HCFC) to hydrofluorocar-bons (HFC) class compounds. Sensitivitydifferences of l00X to l000X have beenreported when comparing CFC- 12 toHFC- 134a with some ionization-based

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sensors. Another example of this varyingsensitivity is an infrared-based sensor. Ithas roughly the same sensitivity toCFC-12, HCFC-123, and HFC-134a,which is not the case for an ionizationdetector.

B.2.2 Detection LimitCertain analytical techniques have well-defined sensitivity values, but these do notexist for refrigerant sensors. The mostcommon measure of how “sensitive” a sen-sor can be is the detection limit. This isdefined as the minimum amount of materi-al a unit can sense that gives a signal atleast two times the background noise level.A sensitive device does not necessarilymean a low-detection limit, although thetwo usually tend to coincide. Detectionlimits are measured in parts per million(ppm) for area monitoring applications.Area monitors typically have detectionlimits as low as 1 ppm, although a moretypical value is 3 to 4 ppm for most com-pounds. For example, a detector with highsensitivity may be able to accuratelydiscriminate concentration levels of 1 ppmor 2 ppm of vapor, while a low-sensitivitydetector may only be able to discriminatein increments of 20 ppm or higher. A re-frigerant sensor must be matched with theintended application. For example, an ion-ization detector that claims a detectionlimit of 2 ppm for CFC-12 does not workvery well for HFC-134a detection. Con-versely, an ionization detector madespecifically for HFC-134a may be toosensitive for CFC- 12 monitoring.

B.2.3 SelectivitySelectivity is defined as the ability todetect only the refrigerant of interest

without interference from other compoundsthat may be present in the area. Selectivityrequirements for area monitoring will varywith each specific installation. It is impor-tant because the monitors must work on acontinuous basis and are thus exposed toother, more potentially interfering refrig-erants at a wider concentration range overa long period of time.

B.2.3.1 Selectivity is a required feature ofan area monitor if there are other refriger-ants present with vastly different thresholdlimit values (TLV). The terms TLV andacceptable exposure limit (AEL) are usedalmost interchangeably in technical liter-ature and tend to cause some confusion.TLVs are the maximum concentration of achemical vapor in air for which workerscan be exposed on a chronic basis (eight-hour work day and a 40-hour work week)without adverse effect over their workinglifetime. These values are established bythe American Conference of Governmentand Industrial Hygienists (ACGIH). AELsare defined as the maximum concentrationof a chemical vapor in air for whichworkers can be chronically exposed asdefined by the manufacturer of the chem-ical. In many cases, manufacturers willintroduce new chemicals to the market-place before ACGIH can establish TLVs.In these cases, AELs will be specified bythe manufacturer and used until ACGIHcan establish TLVs. For practical pur-poses, these values are used interchange-ably to establish chronic exposure limits.In some rare cases, chemical manufactur-ers may establish AELs lower thanACGIH TLVs. In this case, the lower ofthe two values should be used. For ex-ample, equipment rooms with HCFC-123

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chillers (AEL = 30 ppm) may also havechillers with CFC- 11 (TLV = 1,000ppm). Without being able to distinguishbetween the two other refrigerants, anonselective detector will alarm when 30ppm of either refrigerant is detected. Inthis case a small leak of CFC- 11 willtrigger the alarm. This can lead to concernabout excessive HCFC - 123 exposurewhen, in reality, there may be no exposureto that compound and only inconsequentialexposure to the CFC - 11. This can alsolead to false alarms and eventual compla-cency toward alarms. Regardless of thispossibility, some operators still prefernonspecific detection so there is an alarmwhen any refrigerant is detected. Theidentity of the refrigerant will be dis-covered once the leak is pinpointed.

B.3 Electronic Area MonitorDetection Equipment

Electronic area monitor detection equip-ment can be placed into one of threecategories based on selectivity as acriterion:1) nonselective,2) halogen-selective, and3) compound-specific.

B.3.1 Nonselective SensorsThe sensors in this equipment can detectany type of emission or vapor present,regardless of its chemical composition.Detectors in this category are based onelectrical ionization, thermal conductivity,ultrasonics, or metal-oxide semiconduc-tors. These detectors are simple to use,very rugged, and, usually inexpensive.Nonselective sensors are best used in leak

pinpointing applications.

B.3.2 Halogen-Selective SensorsHalogen-selective sensors use a specializedsensor that allows the monitor to detectcompounds containing fluoride, chloride,bromide, and iodide without interferencefrom other species. The major advantage isa reduction in the number of “nuisancealarms” —false alarms caused by the pre-sence of nonrefrigerant compounds (forexample, paint or gas fumes). These detec-tors are easy to use, feature a highersensitivity than nonselective detectors(detection limits are typically < 5 ppm),and are very durable. Due to the partialspecificity of the detector, these instru-ments can be calibrated easily.

B.3.3 Compound-Specific SensorsCompound-specific sensors are the mostcomplex and expensive. These units arecapable of detecting the presence of asingle species without interference fromother compounds. Compound-specific sen-sors are infrared-based (IR), althoughsome of the newer types are infrared-photoacoustic-based (IR-PAS). These nor-mally have detection limits around 1 ppm,depending upon the compound being de-tected. Due to recent improvements intechnology, the price of compound-specificdetectors has dropped but is still in the$3,500 to $4,000 range.

B.3.4 Comparing SensorsThese three types of sensors are comparedin Table B-1, Comparison of RefrigerantSensors.

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Table B-1. Comparison of Refrigerant Sensors

Comments Nonselective Halogen-Selective Compound-Specific

Advantages: ● Simplicity ● Simple/rugged ● Virtually● Ruggedness ● Can be calibrated interference-free

● Good sensitivity ● Can be calibrated● Low maintenance ● Good sensitivity

Disadvantages: ● Poor detection limits ● Not compound-specific ● Complexity/maintenance● Cross-sensitive to other ● Detector lifetime/stability ● Stability questionable

species ● High price● Most cannot be calibrated

Refrigerants ● All CFCs, HCFCs, ● All CFCs, HCFCs. ● All CFCs, HCFCs,Detected: HFCs, blends HFC-134a, blends HFC-134a, blends

● Not recommended due tocross-sensitivity andpoor detection limits

Other: ● None ● Where only one ● Performance degraded inrefrigerant is used “dirty” environments

● In moderately clean ● Preferred type for use inequipment rooms multi-refrigerant

environments

B. 4 Refrigerant Sensors greatest hazard is associated with refrig-erant spills and the possibility of asphyxi-

AHRAE 15-1994 requires refrigerant ation. Refrigerant gases are heavier thansensors/monitors in all mechanical equip- air and, if undisturbed, tend to fill a roomment rooms for all refrigerants. The from the floor up, displacing the air.refrigerant sensor has the advantage ofproviding fast detection of refrigerant B.4.2 Other Refrigerant Groupsleaks. This capability can minimize the Other groups of refrigerants are A2, A3,loss of valuable refrigerant. Its high cost B 1, and B2 (HCFC-123 is a B1 refriger-can be justified by the cost savings associ-ated with avoiding the loss of an entire orpartial charge.

B.4.1 Group Al RefrigerantsGroup Al refrigerants include CFC-11,-12, -13, -113, -114, -500, and -502;HCFC-22; and HFC-134a. These refrig-erants are classified low in toxicity andpossess no flame propagation. Their

ant). Refrigerant sensors which detect thespecific refrigerant in use are required toactivate the alarm at no more than thecorresponding TLV.

B.4.2.1 A refrigerant sensor can be usedto meet ASHRAE 15-1994’s monitoringrequirements for Group A 1 refrigerants.Though more expensive than an oxygendeprivation sensor, the refrigerant sensor

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has the advantage of providing much fasterdetection of refrigerant leaks. This capabil-ity can minimize the loss of valuable re-frigerant. The additional cost of a refrig-erant sensor may be justified by the costsavings associated with avoiding the lossof an entire or partial charge.

B.4.2.2 Any equipment room containing amixture of Group A 1 and B 1 refrigerantsmust meet the requirements of each systemindividually. This means if an equipmentroom houses an R-11 chiller and an R-123chiller, it must also contain both anoxygen deprivation sensor and a refriger-ant vapor monitor. Alternatively, tworefrigerant vapor sensors (one for R-11and one for R-123) could be used.

B.5 Continuous Duty AreaMonitors

Area monitors are used today to check therefrigerant vapor level on a continuingbasis in an equipment room or other loca-tions where exposure can occur. There areseveral reasons for monitoring, includingpersonnel health and safety protection,conservation of expensive refrigerants, andprotection of valuable refrigeration equip-ment.

B.5.1 Monitor CharacteristicsIf a monitor is used to continuously samplethe air in an equipment room, it shouldhave several qualities that short-term orleak-checking monitors do not require.These include low “O” drift or an “auto-zeroing” capability and outputs to triggerexternal alarms to notify the proper basepersonnel. Continuous monitors should berefrigerant-specific to prevent nuisance

alarms, caused by the presence of somecompound (for example, gasoline orpaints) in the area other than the targetcompound. Monitors with poor selectivity ywill alarm on compounds other than refrig-erant, such as cleaning agents or paints.

B.5.2 Monitor RequirementsASHRAE 15-1994 requires a monitor beable to actuate an alarm and start mechan-ical ventilation. This corresponds to thebasic function of the monitor to alertpersonnel that the refrigerant level isabove the TLV or AEL. Devices used forlongterm monitoring should also be stableover the range of temperatures, voltages,humidities, and barometric pressures towhich they will be exposed. One of theoutputs should notify base emergencypersonnel in the event of a major releaseof refrigerant. Last, but not least, theyshould require minimal maintenance.

B.5.3 Calibration StabilityCalibration stability is a very importantaspect of monitors used for long-termmonitoring. Stability is provided by theelectronics used to read the sensor output.In general, the electronics must be able tocorrectly interpret sensor output under allequipment room conditions, such aschanges in temperature and humidity. Cali-bration can be performed by the manufact-urer of the monitor for approximately $200to $250. Always recalibrate an areamonitor after a repair involving the re-placement of a sensor, bridge board, or amain control board. The replacement ofany of these three components can signifi-cantly affect the calibration of the unit.There are many situations in which morethan one type of refrigerant is being

B-5


monitored. Because all monitors can onlybe calibrated for a single refrigerant, thefollowing criteria should be used in se-lecting the refrigerant sensor to use:always use R-123 if that is one of therefrigerants being monitored. R-123 has anAEL of 30 ppm. All other common refrig-erants have much higher AELs.

B.5.3.1 Although most area monitors willdetect all halogen-based refrigerants, theirsensitivity varies with the specific refrig-erant type. The commonly used refriger-ants can be segregated into four groups,from the highest sensitivity (highestreading for a given concentration) tolowest sensitivity as shown below:

Highest Sensitivity R-n, -22, -123

Moderate Sensitivity R-502

Lower Sensitivity R-12, -500, -114

Lowest Sensitivity R-134

Choose the refrigerant for which the de-tector has the lowest sensitivity. Forexample, if the unit is monitoring a roomthat has both R-12 and R-22, choose R-12for the calibration.

B.5.3.2 Typically, all sensors will last forapproximately two to five years from thedate installed before a new sensor isrequired. As refrigerant is detected, thesensor loses some amount of its ability todetect refrigerant the next time. The life ofa sensor is primarily determined by theamount of refrigerant it senses over aperiod of time. The average cost to replacea sensor is approximately $300 to $350each.

B.5.4 CharacteristicsMonitors should also have a method of set-ting the “0” reference point. Those usedon a long-term basis should either have avery small “0” drift (ppm) between inspec-tions or an “auto zero” feature.

B. 6 Monitor Alarm Outputs

Monitors must provide a relay to annun-ciate an alarm signal when the TLV, AEL,or oxygen limit is reached. It can be usedto trigger an alarm, light, or bell; signalthe condition to other parts of the building;and energize the ventilation system topurge the room. Equipment room alarmsignals and start-up of mechanical ventila-tion systems should be done directly by themonitor. Remote alarm indicators can beconnected through a building automationsystem (BAS). Some monitors provideseveral relay outputs that can be set totrigger at various levels of refrigerantconcentration. These can be used to clearlydefine the danger of exposure.

B.6.1 First-Stage AlarmThe first stage of alarm must occur at theTLV or AEL (that is, the concentration foreight hours per day, 40 hours per week fortheir working life, to which nearly allemployees can be exposed without adverseeffect). At this level, purge rate ventilationof the space should be initiated. Occupantscan remain in the room if they are work-ing to contain a leak. Use of NationalInstitute for Occupational Safety andHealth (NIOSH)-approved respiratory pro-tection is recommended, but not required.

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B.6.2 Second-Stage AlarmThe second-stage alarm should be set atthe short-term exposure limit (STEL)which can be up to three times the TLV orAEL. ACGIH allows brief exposure (up to15 minutes) at this level in a work shift.This level of alarm indicates that the roomshould only be occupied by personnel,properly equipped with respiratoryprotection, intent on eliminating therefrigerant source.

B.6.3 Third-Stage AlarmThe third-stage alarm, or alternate secondlevel, is the emergency exposure limit(EEL). The EEL defines a concentrationthat a worker should only be exposed torarely in a lifetime. In addition, it will notcause permanent adverse health effects orinterfere with a worker’s escape. An ex-posure time is generally given with theconcentration (for example, 1000 ppm forone hour); however, at this level it shouldbe mandatory that all occupants exit thespace immediately. This level would onlybe expected when a major spill hasoccurred.

B.6.4 Self-MonitoringMany monitors have the capability of de-tecting failure in their operations. They areprovided with an output signal, such as arelay, which can be used to report a sensorfailure. Examples of failures include: lowairflow through the monitor, circuit fail-ure, and a saturated or absent sensorsignal. Loss of the monitor’s supply powercan also be detected if the alarm contactsof the monitor are normally powered open.This output should signal an alarm condi-tion to the building operator so the monitorcan be checked and returned to operation.Upon receiving such a signal, the operator

should bring a portable monitoring deviceto the equipment room when checking thepermanent monitor. He should ascertainthe level of refrigerant in the mechanicalequipment room before entering.

B.6.5 Remote ResetSome monitors contain a remote resetinput that allows the alarm to be resetfrom a remote location. If the monitorcontains this feature, the reset switchshould be located outside the equipmentroom door. This allows an operator toreset the alarm before entering the room.If the alarm can be successfully reset, thebuildup of refrigerant has cleared. If thealarm does not reset, additional stepsshould be taken before the room is enter-ed. The technician should:● wear a self-contained breathing

apparatus (SCBA);● determine refrigerant concentration

level with a hand-held monitor; and● obtain additional ventilation using

existing systems or portable units ifhigh concentration levels are detected.

B.6.6 Serial SignalSome monitors provide a O to 10 vDC,4 to 20 mA or serial signal that is propor-tional to the level of refrigerant sensed bythe monitor. This signal can be used toprovide a remote indication of the refriger-ant level in the equipment room. Example:

One use of this output could signala meter located outside the entrydoor to the equipment room. Thiswill help operating personnel decideif SCBA is necessary or if the re-frigerant in the room has been suc-cessfully purged by the ventilationsystem.

B-7


SCBAs are required:● in atmospheres deficient in oxygen

(concentrations of oxygen in air< 19.5 percent), or

● if the concentration of chemical vaporin air is equal to or greater than theconcentration which is consideredimmediately dangerous to life andhealth (IDLH).

IDLH values are specified by NIOSH (seeTable C-1, Physical Properties ofRefrigerants, in Appendix C). This is notintended to be a complete discussion of therequirements established in federalregulations for respiratory protection.The user of this Handbook should consult29 C.F.R. 1910.134 and ANSIZ88.2- 1980 for detailed requirements.When tied to a building automationsystem, a signal can be used to alertoperating personnel of a leak, initiateventilation purge of the room, andgenerate an electronic log of therefrigerant level in the equipment room.

B.6.7 AdvantagesMonitoring equipment room refrigerantconcentrations with a BAS may eventuallybecome common practice for all refrig-erants. This level of control not onlymonitors refrigerant level and initiatesnecessary alarms, it also automaticallyalerts the service order desk responsiblefor repair of the equipment. This providesan inexpensive means of having a trainedexpert, who can quickly respond to aproblem, constantly oversee the operationof the equipment room.

B.6.7.1 Refrigerant concentration in theequipment room can be logged electron-ically y and documented. This provides

documentation that refrigerant concentra-tions are maintained below the appropriateAEL. It also allows employees to feelcomfortable they are working in a safeenvironment.

B.6.7.2 A refrigerant vapor monitor canbe used for early detection of refrigerantleaks and may prevent significantrefrigerant loss.

B.6.7.2.1 Monitoring the purge unit witha BAS for excessive purge unit operatingtimes can also provide valuable informa-tion that could lead to early leak detection.

B.6.7.3 Purge unit run times can beautomatically logged and plotted in graphform to identify trends. In addition, analarm message can be triggered to alert theoperator if the purge rate exceeds somepreset limit. In general, purge unit runtimes in excess of one hour per week are indicative of excessive leakage. This valueis dependent on the capacity of the purgeunit and the internal volume of the chillerand is therefore only a guideline. The chil-ler manufacturer should be consulted todetermine the actual maximum, allowablepurge unit run times for each chiller whichare to be expected of a chiller in goodoperating condition.

B.7 Sensor Locations

The refrigerant sensors associated with thearea monitors must be properly located.Some refrigerant leak detectors are capableof monitoring multiple locations and mayuse multiple sensors in one unit. Otherleak detectors are single-zone units capableof monitoring only one location. Some of

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the key factors in determining sensorlocations are:● leak source locations,● air flow patterns, and● where room occupants are most likely

to be exposed to refrigerants throughinhalation.

Using occupant safety as a guide, therecommended height for the sensor is 18inches above the floor. The sensor shouldalways be below the common breathingzone height of five feet. When undisturbedby air currents, refrigerants released into aspace fall to the floor and spread out.They are three to five times heavier thanair and seek the lowest areas. Once theseareas are “full,” the space will fill fromthe bottom up, much as it would if it werebeing filled with water.

B.7.1 Locating Sensors“Locate the sensor where refrigerant islikely to concentrate, “ is the only directiongiven by ASHRAE 15-1994 to locate therefrigerant monitor sensor. This recom-mendation is necessarily vague, due to thewide variety of equipment room configura-tions. Instructions provided by the monitormanufacturer should be followed whenlocating the sensor.

B.7.1.1 Because the sensor measures theconcentration of refrigerant in the air, eachzone inlet tube should be mounted where itis most likely to sense leaking refrigerant,Place the inlet as close as possible to thearea of potential leaks; on the downstreamside of the air flow pattern in the room.

Place the inlet close to the floor, becauserefrigerants are typically heavier than air.Locate the control unit so the farthest pick-up point will not exceed the manufactur-er’s recommendations for zone inlet tubelength.

B.7.1.2 Moisture can damage refrigerantsensors. Pickup points must be located andprotected, where necessary, to preventwater from entering the system.

B.7.1.3 Figure B-1, Sensor PickupPoints, shows a general location of thepickup points where sensors should belocated in accordance with ASHRAE15-1994.

B.8 Vendor Listing

The following is a partial listing ofcompanies that sell leak detectors. Theseare not recommendations and the AirForce does not endorse these companies.

B.8.1 Nonselective DetectorsAIM USA12919 Southwest Freeway, Suite 170P.O. Box 720540Stafford, TX 77477(713) 240-5020

B.8.2 Halogen-Selective DetectorsYokogawa Corporation of America2 Dart RoadShenandoah Industrial ParkNewnan, GA 30265-1094(800) 447-9656

B-9

Appendix B – Refrigerant Sensors and Monitoring of Equipment Rooms

Air InletVia ThreePairs ofLouvers

Exhaust Fan

Figure B-1. Sensor Pickup Points

B-10


Leybold-Inficon, Inc.Two Technology PlaceEast Syracuse, NY 13057(315) 434-1246

SenTech CorporationP.O. Box 429052020 Production DriveIndianapolis, IN 46242(317) 248-1988

B.8.3 Compound-Specific DetectorsFoxboro CorporationEMO Division, P.O. Box 500600 N. Bedford StreetEast Bridgewater, MA 02333(508) 378-5400

Gas Tech, Inc.8407 Central AvenueNewark, CA 94560(510) 794-6200

B-11 (B-12 Blank)


Appendix C — Refrigerant Storage Recommendations and Requirements

Appendix C — Refrigerant StorageRecommendations and Requirements

ABSTRACT: This appendix explains the refrigerant storage recommendations and requirementsfor refrigerant storage facilities, refrigerant storage container types, labels and markings,transportation of refrigerant issues, and the safe handling of refrigerants. It provides health andsafety issues for refrigerants.

C.1 Introduction

Refrigerants, whether regulated or non-regulated, should be stored in a controlledenvironment. From a safety standpoint, itis important to limit access to refrigerants;some refrigerants are very toxic, flamma-ble, or stored in high-pressure containers.With the implementation of productionbans of chlorofluorocarbons (CFCs) in1995, decreasing availability and increas-ing price, inventory control of refrigerantsis very important. If possible, storerefrigerants in a single location to providebetter control and management. This willsimplify managing refrigerant inventoriesand assure the necessary recordkeeping isbeing accomplished. If refrigerant is storedwithin an enclosed space, the area monitorand emergency ventilation system costsavings are significant if only one site isused; otherwise, all storage sites willrequire these systems.

C.2 Refrigerant StorageRequirements: EnclosedSpace

Buildings, or areas within buildings, de-signed or used specifically as enclosed

refrigerant storage facilities shall complywith ASHRAE 15-1994, Safety Codes forMechanical Room Design (see Appendix J,Application of ASHRAE Equipment RoomDesign Requirements). ASHRAE 15-1994guidelines include, but are not limited to:refrigerant storage facility ventilation andexhaust requirements, refrigerant monitorsand alarms, and on-site self-containedbreathing apparatus. ASHRAE 15-1994limits the amount of stored refrigerant in amachinery room to not more than 330 lbs(150 Kg) of refrigerant, in addition to thecharge in the equipment plus the refriger-ant stored in a permanently attached re-ceiving vessel. Whenever refrigerant isstored within a building, such as a refrig-eration shop, it is preferable for it to be inan enclosed room. Otherwise, everyone inthe shop is at constant risk of exposure andpossible asphyxiation.

C.3 Refrigerant Storage Recom-mendations: Open Space

Currently, there are no regulations for thestorage of refrigerants in a nonenclosedrefrigerant storage facility, other than tofollow safe refrigerant handling practices.The following practices are recommended.

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●

●

●

All storage areas should be under aroof to protect them from weatherextremes and be of such a size as tokeep direct sunlight off the refrigerantcontainers. The area should be en-closed, at a minimum, with a chain-link fence for security purposes.An open enclosure should preferablybe a stand-alone entity.If an enclosure is located adjacent to abuilding with which it shares a com-mon wall (with the other three sidesopen), it is recommended no door beinstalled in the common wall within theconfines of the enclosure.

C.4 Other Recommendations

Technicians, or anyone who has the poten-tial to be working with or around refriger-ants, should complete a training programwhich meets the minimum guidelines setforth by OSHA 1910.120, includingtraining on the flammability and toxicity ofrefrigerants commonly used on the base;and safe work practices and handling ofrefrigerants, especially when working inan enclosed space (for example, use ofself-contained breathing apparatus (SCBA)and refrigerant vapor monitoring). Emer-gency procedures in response to accidents,spills, and exposure involving refrigerantsshould be provided during training.

C.5 Refrigerant Health andSafety Issues

There are many health and safety issuesassociated with both the new, alternativenon-CFC refrigerants, and CFCrefrigerants. Several of these issues will beaddressed in the following sections.

C-2

C.5.1 Physical Properties ofRefrigerants

Table C-1, Physical Properties of Refrig-erants, provides a quick overview of therefrigerants used in air conditioning andrefrigeration (AC/R) applications, includ-ing: type and designation number, chemi-cal formula, boiling point, threshold limitvalue (TLV), acceptable exposure limit(AEL), short-term exposure limit (STEL),and immediately dangerous to life andhealth (IDLH) information. Values forsome of these items are not readily avail-able or have not been determined.

C.5.1.1 The refrigerants which are CFC,hydrochlorofluorocarbon (HCFC), andhydrofluorocarbon (HFC) compounds havebeen identified under refrigerant by replac-ing the “R” designation with the appropri-ate compound designation. The boilingpoint refers to the temperature at whichthe refrigerant will boil off as a gas atatmospheric pressure.

C.5.1.2 The various refrigerant concen-tration levels at which an individual can besafely exposed are usually time-dependent.These levels are indicated by the TLV,AEL, STEL, and IDLH and are expressedin parts per million (ppm).

C.5.1.2.1 The compound TLVs are estab-lished by the American Conference ofGovernment and Industrial Hygienists(ACGIH). TLVs are the maximum chemi-cal vapor concentration in air to whichworkers can be exposed on a chronic basis(eight-hour work day and 40-hour workweek for a working lifetime) withoutadverse affect. Several years can elapsebefore the TLVs for a new chemical areestablished.


Table C-1. Physical Properties of Refrigerants

BoilingChemical Point TLV AEL STEL IDLH

Refrigerant Name Formula ° C / ° F (ppm) (ppm) (ppm) (ppm)

Group A1

Trichlorofluoromethane C C l3F 23.9/75 1,000 1,000 -- 10,000CFC-11

- 3 0 / - 2 2 1 , 0 0 0 1 , 0 0 0 -- 50,000CFC-12 Dichlorodifluoromethane C C l2F 2

-82/-115 -- -- -- 50,000CFC-13 Chlorotrifluoromethane C C l F3

-57.81-72 1,000 1,000 -- --

-128/-198 - - - - - - --

R-13B1 Bromotrifluoromethane C B r F3

Tetrafluoromethane C F4

(carbon tetrafluoride)R-14

HCFC-22 Chlorodifluoromethane CHClF2-40.6/-41 1,000 1,000 1,250 - -

4 7 . 8 / 1 1 8 1 , 0 0 0 1 , 0 0 0 1,250 4,500CFC-113 Trichlorotrifluoroethane CCl2FCClF2

CFC-114 Dichlorotetrafluoroethane CClF2CClF2 3.3/38 1,000 1,000 -- 50,000

-38.9/-38 1,000 1,000 -- --

-26/15.2 1,000-- -- --

1,000 - - -- 50,000

CFC-115 Chloropentafluoroethane CClF2CF3

HFC-134a 1,1, 1,2-Tetrafluoroethane CH2FCF3

CFC-400 R-12 and R-114 CCl2F 2/ C2C l2F 4

HCFC-401a R-22/R-152a/R-124 CHC1F2/CH3CHF2/(53%/13%/34% by Wt) CHClFCF3

-32.81-27 -- 800 -- --

HCFC401b R-22/R-152a/R-124 CHCIF2/CH,CHF 2/(61%/11%/28% by wt) CHC1FCF3

HCFC-402a R-22/R-125/R-290 CHClF2/C3H8/(30%/60%/2% by Wt) CHF2CF3C2HF5

HCFC-402b R-22/R-125/R-290 CHClF2/ C3H 8

(60%/38%/2% by Wt) CHF2C F3C2H F5

HFC-404a

CFC-500

CFC-502

CFC-503

R-143a/R-125/R-134a(52%/44%/4% by Wt)

R-12/152a (73.8%/26.2% by wt)

CH3CF3/CHF 2CF3/C H2F C F3

CCL2F2/CH3CHF3

-35/-30.5 - - 9 4 0 - - - -

-49/-56.6 - - 1,000 - - - -

-47/-53.3 - - 1,000 - - - -

-46.7/-52 -- 1,000 - - --

-33.31-28 1,000 1,000 -- --

45/-49.7 1,000 1,000 -- -- R-22/l 15 (48.8%/51.2% by Wt)

CHClF2/CClF 2CF3

R-23113(40.1%/59.9% by Wt)

CHF3/CClF3 -88/-126 -- -- -- --

C-3

Appendix C – Refrigerant Storage Recommendations and Requirements

Table C-1. Physical Properties of Refrigerants (continued)

ChemicalName Formula

BoilingPoint TLV

° C / ° F (ppm)AEL(ppm)

STEL(ppm)

--

IDLH(ppm)

--

Refrigerant

HFC-507 R-125/R-143a CHF2CF3/CH3CF3

(50%/50% by wt)-46.7/-52 -- 1,000

--R-744 Carbon Dioxide CO2 -78/-109 5,000 30,000 50,000

Group A2

CFC-142b l-Chloro-l, 1,-Difluoro- CH3CC1F2 - 1 0 / 1 4 -- 1,000** -- --ethane

1,l-Difluoroethane CH3CHF2 -25/-13 -- 1,000** -- --HFC-152a

Group A3

R-170 Ethane* C2H6-89/-128 -- -- -- --

R-290 Propane* C3H8 -42.2/-44 1,000 -- -- 20,000

R-600 Butane C4H10 -0.6/31 800 -- -- --

R-600a 2-Methylpropane CH(CH3) 3 -11.7/11 -- -- -- --(Isobutane)

R-1 150 Ethene (Ethylene) C2H4-104/-155 -- -- -- --

R-1270 Propene (Propylene) C3H6 -47.81-54 -- -- -- --

Group B1

HCFC-123 2,2-Dichloro-l,1,l-Tri- CHC12CF3 27.6/81.7 -- 30 -- --fluoroethane

R-764 Sulfur Dioxide SO2 -10/14 2 -- 5 100

Group B2

-24.4/-12 5 0 -- 100

-24.4-12

10,000R40 Chloromethane CH3Cl(Methyl Chloride)

R-611 Methyl Formate HCOOCH3

R-717 Ammonia NH3

31.7/89 100 -- 150 5,000

-33.3/-28 25 -- 35 500

* Simple asphyxiant** Work place Environmental Exposure Limit as defined by American Industrial Hygienists Association

C-4


C.5.1.2.2 The compound AEL is deter-mined by the manufacturer of a chemicalor substance. It is listed in the materialsafety data sheet (MSDS) for the substancefor guidance of personnel exposure. Thisvalue is typically used until ACGIH canestablish TLVs. Often the AEL and TLVare equal and used interchangeably.

C.5.1.2.3 The STEL is defined byACGIH as a 15-rninute time-weightedaverage exposure which should not beexceeded at any time during a work day,even if the eight-hour time-weighted aver-age is within the TLV. Exposures at theSTEL should not be longer than 15 min-utes and should not be repeated more thanfour times per day. There should beatleast 60 minutes between successive expo-sures at the STEL. STEL represents theconcentration to which workers can beexposed continuously for a short period oftime without suffering from● irritation;● chronic or permanent tissue damage; or● narcosis of sufficient degree to increase

the likelihood of accidental injury,impair self-rescue, or materially reducework efficiency,

provided the daily TLV is not exceeded. Itis not a separate, independent exposurelimit. Rather, it supplements the time-weighted average (TWA) limit where thereare recognized acute effects from a sub-stance whose toxic effects are primarily ofa chronic nature. STELs are recommendedonly where toxic effects have been report-ed from high, short-term exposures ineither humans or animals. Very few refrig-erants have had STEL values developed.

C.5.1.2.4 IDLH values are specified bythe National Institute of OccupationalSafety and Health (NIOSH). These valuesrepresent a vapor concentration level that,when present, results in oxygen concentra-tions to drop below 19.5 percent.

C.5.1.2.5 The oxygen content of normalair at sea level is approximately 21 per-cent. Physiological effects of oxygen defi-ciency in humans are readily apparentwhen the oxygen concentration in the airdecreases to 16 percent. These effectsinclude impaired attention, judgment andcoordination, and increased breathing andheart rate. Oxygen concentrations below16 percent can result in nausea and vomit-ing, brain damage, heart damage, uncon-sciousness, and death. To take into accountindividual physiological responses anderrors in measurement, concentrations of19.5 percent oxygen or lower are con-sidered to be indicative of oxygendeficiency.

C.5.2 Refrigerant ExposureRefrigerants handled in accordance withthe manufacturer’s recommended exposurelimits pose no acute or chronic inhalationtoxicity hazard. However, there are certainprecautions which should be undertakenand are as follows.

C.5.2.1 At room temperatures, refrigerantvapors have little or no effect on the skinor eyes. Inhaling high concentrations ofrefrigerant vapor may cause temporarycentral nervous system depression withnarcosis, lethargy, and anesthetic effects.Other effects may be dizziness, intoxica-tion, and a loss of coordination.

C-5


Continued breathing of high concentrationsof vapors may produce cardiac irregulari-ties (cardiac sensitization), un-consciousness, and, with gross overexpo-sure, death. If any of the above symptomsare experienced, move to fresh air andseek medical attention.

C.5.2.2 Cardiac sensitization can occur ifvapors are inhaled at concentrations wellabove the AEL. This can cause the heartto become sensitized to adrenaline, leadingto cardiac irregularities and possible cardi-ac arrest. The likelihood of these cardiacproblems increases with physical oremotional stress. Immediate medical atten-tion must be provided if exposure to highconcentrations of refrigerants occurs. Donot treat with adrenaline (epinephrine) orsimilar drugs. These drugs may increasethe risk of cardiac arrhythmias and cardiacarrest. If the person is having difficultybreathing, administer oxygen. If breathinghas stopped, give artificial respiration.

C.5.2.3 Suffocation can occur when alarge release of vapor occurs, such as froma large spill or leak. These vapors mayconcentrate near the floor or in low spotsand will displace the oxygen available forbreathing, causing suffocation. When alarge spill or leak occurs, always wearappropriate respiratory and other personalprotective equipment before entering thearea.

C.5.2.4 When working with a piece ofrefrigeration equipment in an equipmentroom or enclosed area, ensure that therelief and purge vent piping has beenrouted outdoors, away from air intakes.Make certain the area is well-ventilated.

If necessary, use auxiliary ventilation tomove refrigerant vapors. Check that airmonitoring equipment has been installed todetect leaks. Ensure the area is clear ofvapors prior to beginning work.

C.5.2.5 Refrigerants that are liquid atroom temperature tend to dissolve theskin’s protective fat, causing dryness andirritation, particularly after prolonged orrepeated contact. Protective clothingshould always be worn when there is arisk of exposure to liquid refrigerants.Where splashing is possible, always weareye protection and a face shield. If theeyes are splashed, repeatedly flush themwith water for at least 15 minutes. Whenhandling refrigerants, always wear linedbutyl gloves to avoid prolonged skin con-tact and chemical splash goggles to avoideye contact. Provide SCBA for use in theevent of a major spill or system failure.

C.5.3 Flammability PrecautionsTypical AC/R refrigerants are nonflam-mable and nonexplosive. However, mixingrefrigerants with flammable gases (such asair) or liquids can result in a flammablesolution. Therefore, refrigerants shouldnever be mixed with any flammable gas orliquid. Refrigerants should not be exposedto open flames or electrical heating ele-ments. Though most refrigerants are notflammable at ambient temperatures andatmospheric pressure, tests have shownsome types to be combustible at pressuresas low as 5.5 psig at 177° C (351° F)when mixed with air at volumetric concen-trations of generally more than 60 percentair. At lower temperatures, higher pres-sures are required for combustibility.

C-6


Refrigerants should not be used or allowedto be present with high concentrations ofair above atmospheric pressure.

C.6 Disposable and ReusableRefrigerant Cylinders

Refrigerants are contained in both dispos-able and reusable shipping containers orcylinders. Since the refrigerant-containingcylinders can be pressurized, they areconsidered pressure vessels. They mustcomply with federal and state laws regu-lating transportation and usage of suchcontainers.

C.6.1 Identifying ContainersBoth disposable and reusable cylinders arepainted (or otherwise distinguished) in acolor code system. This code was volun-tarily established by the refrigerant manu-facturers to identify their products. Thecommon refrigerant colors and identifica-tion are:

R-11 OrangeR-12 WhiteR-13 Light BlueR-22 Light GreenR-113 PurpleR-114 Dark BlueR-123 Light Grey (Silver)R-134a Light Blue (Sky)R-401a CoralR-401b Yellow BrownR-402a SandR-402b OliveR-404a OrangeR-500 YellowR-502 Light PurpleR-503 AquamarineR-507 TealR-717 SilverNH3 Silver

The shade of color may vary from onemanufacturer to another. Verify contentsby means other than color. Every refriger-ant cylinder is silk-screened with product,safety, and warning information. Manu-facturer technical bulletins and MSDSs areavailable upon request. Even though cylin-ders are designed and manufactured towithstand the saturated pressure of R-502(the base refrigerant), it is not recommend-ed any cylinder be repainted with a differ-ent color and used with another refriger-ant.

C.6.2 Container PressureAll refrigerant cylinders come equippedwith a pressure-relief valve designed toprevent the cylinder from being over-pressurized, either during the filling of thecylinder with refrigerant or during thestorage of the cylinder due to possibleexposure of the cylinder to elevated tem-peratures. If the refrigerant pressure insidethe cylinder exceeds the preset pressure ofthe pressure relief valve, the pressure-relief valve allows the automatic venting ofrefrigerant to reduce the pressure in thecylinder. Pressure-relief safety devices areof the frangible (rupture) disc style, orspring-loaded relief integrated into thevalve stem of the cylinder. Neither adjustnor tamper with pressure-relief valves.

C.6.3 Reusable ContainersReusable cylinders meet Department ofTransportation (DOT) specification4BA-300, with a water capacity of 122.7pounds. Low boiling point, high vaporpressure refrigerants such as R-13 andR-503 are supplied in cylinders with DOTspecification 3AA-180 or 3AA-2015,respectively. These cylinders are

C-7


characterized by a combined liquid/vaporvalve, located at the top of the cylinder.A dip tube feeding the liquid valve isimmersed to the bottom to allow liquid re-moval without inverting the tank. Refriger-ant can be removed in either gas or liquidphase through selection of the gas or liquidvalve. The large, reusable cylinders bear astamp on the shoulder which provides thefollowing information:● OWNER’S NAME (abbreviated),● DOT SPECIFICATION NUMBER for

the cylinder,● SERIAL NUMBER of the tank,● TEST DATE (month and year),● MANUFACTURER’S SYMBOL, and● WATER CAPACITY (in pounds

weight).

C.6.3.1 DOT specifications require dis-posable refrigerant cylinders be rated for aservice pressure of 260 pounds per squareinch (psi). Under laboratory tests, onecylinder per 1,000 produced is pressurizedto the point of failure. The cylinder mustnot rupture below 650 psi. These cylindersare constructed of common steel, which isprone to oxidation (rust). Rust can weakenthe wall and seams of the cylinder to thepoint where the cylinder can no longertolerate the pressure of the refrigerantinside. On the top of disposable cylindersis a single-acting plastic valve. Handles areprovided, which can serve as rests forinverted liquid access from the cylinder.Disposable cylinders are to be stored indry locations to prevent corrosion, andtransported carefully to prevent abrasion ofpainted surfaces. They are not to be re-filled. The penalty for transporting arefilled disposable cylinder is a fine up to$25,000 and five years of imprisonment.

C-8

Recycle disposable cylinders as scrapmetal. When the cylinder is empty, ensureall pressure is released to zero psi. Thecylinders should be rendered useless forany purpose.

C. 7 Labels and Markings(DOT Requirements)

Specific container labeling and markingrequirements apply for all DOT-regulatedhazardous materials. DOT hazardousmaterials designations should not beconfused with EPA hazardous materials.They are solely concerned with materialtransportation issues, not environmentalissues. For instance, DOT regulates mate-rial as hazardous if it is capable of causinginjury or property damage due to an acci-dental release or failure of its packagingduring shipment on public roads, railways,and airways. There are nine classes ofDOT hazards. Only Class 2, Division 2.2(nonflammable gases), is pertinent to thecommon refrigerants. This rating isattributable to the pressurized nature of therefrigerant in its container. The applicableAC/R refrigerants are R-12, R-22,R-134a, R-401a, R-401b, R-402a, R-402b,R-404a, R-500, R-502, and R-507 shippedin cylinders and ton tanks. They requiremarking and labeling. R-1 1, R-113,R-1 14, and R-123 are not DOT-regulatedhazardous materials; therefore, DOTlabeling and marking requirements do notapply.

C.7.1 LabelingEach cylinder shall display a DOT dia-mond (square-on-point) “NonflammableGas” label. The 4-inch x 4-inch green dia-mond-shaped label may be printed on a tag

Appendix C – Refrigerant Storage Recommendations and Retirements

and securely attached to the cylinder’svalve protection cap prior to shipment.Ton tanks require two DOT NonflammableGas labels, one on each end.

C.7.2 MarkingEach container shall be marked with aproper DOT shipping name and appro-priate United Nations (UN) four-digitchemical or hazard class identificationnumber.

C.7.3 Precautionary LabelsEach container shall display a precaution-ary label prepared in accordance withANSI 2129.1-88 and Compressed GasAssociation C7-92. This label will include:●

●

●

●

●

●

●

●

●

product identity;antidotes;signal word;notes to physicians;statement of hazards;instructions in case of contact or expo-sure;precautionary measures;instructions in case of fire, spill, orleak; andinstructions for container handling andstorage.

C.7.4 Warning LabelsSince May 1993, warning labels have beenrequired on containers of DOT Class 2Division 2.1 (flammable gases) and Divi-sion 2.2 substances, as well as productscontaining or made with either of thesesubstances.

C.8 Transportation ofRefrigerants

The shipper of recovered refrigerant isresponsible for determining if there are

any state or local regulations restrictingtransportation, such as classifying recov-ered refrigerant and oil mixtures as haz-ardous wastes. The EPA does not classifythese materials as hazardous waste.

C.8.1 Shipping PapersShipping papers are required wheneverrefrigerant is transported using publicroadways, railroads, and airways. Thisincludes transfer of refrigerants betweenAir Force bases. The shipper is required toproperly fill out the shipping papers whenreturning the recovered refrigerant. Theshipping papers must always contain:● the quantity and type of container used

(for example, “2-RETURNABLECYLINDERS”);

● the total gross weight of recoveredrefrigerants;

● the shipping name (for example,Chlorodifluoromethane Mixture);

● the DOT hazard class (for example,“NONFLAMMABLE GAS”); and

● the UN identification number (forexample, “UN1018”).

For material not regulated by DOT as ahazardous material, the words "Not Regu-lated by DOT" are recommended, but notrequired.

C.8.2 Shipping Tags and PlacardsWhen a full or partially-full container isshipped, the shipper will be required toaffix a DOT hazard label to the container.Typically, this is a green, 4-inch squaretag, reading “NONFLAMMABLE GAS”,that can be tied to the valve cover. If acontainer is empty and has no residualpressure, a DOT hazard tag is notrequired. If the shipper is sending 1,000pounds (gross weight) or more of a

C-9


hazardous material on the truck, DOT include the appropriate UN 4-digit identifi-regulations require the shipper to provide cation number. Affixing the placards to thethe motor carrier with four Nonflammable truck is the responsibility of the motorGas place cards. For materials being trans- carrier.ported in ton tanks, the placards must also

C-10

Appendix D — Refrigerant Leak Detection Methods and Equipment

Appendix D — Refrigerant Leak DetectionMethods and Equipment

ABSTRACT: This appendix addresses refrigerant leak detection methods and equipment. Thecommon leak locations on high- and low-pressure machines are addressed. The leak detectionmethods include those applicable for high- and low-pressure refrigerants used within bothoperating and idle equipment. The portable equipment available to pinpoint leak locations arepresented with advantages and disadvantages of each type. Sensitivity, detection limits, andselectivity criteria for detectors are discussed.

D.1 Introduction

The Environmental Protection Agency(EPA) has promulgated new regulations,40 C.F.R. Part 82 (1993), in response tothe Clean Air Act Amendments (CAAA).They resulted in an increased emphasis onefforts to reduce the use of refrigerantsdue to leakage losses. This appendixprovides an overview of methods andtechnologies which are currently availableto aid service technicians in the location ofrefrigerant leak sources.

D.2 Background

A large amount of refrigerant is lost dur-ing normal chiller operation. This lossmust be reduced significantly. The majorchiller manufacturers believe 12 to 13percent of low-pressure refrigerant emis-sions are due to the use of inefficientpurging equipment. This loss can be ashigh as seven pounds of refrigerant forevery pound of air purged on systemsmanufactured prior to the mid- 1980s.Refrigerant leakage occurs in high-pressure

chillers and direct expansion systems aswell, although these losses are primarilydue to mechanical failures of piping sys-tems, pressure vessels, and gasket materi-als. Manufacturers of refrigeration equip-ment believe that approximately 40 percentof emissions are due to leakage fromrefrigeration systems caused by normaloperation and wear. These types of leaksare most often found in tubing, flanges,O-rings, and other connections. An on-going program of leak detection is the bestsolution for managing the amount of re-frigerant lost during “normal” operations.This requires a knowledge of the equip-ment, methods available to the technician,and the advantages of each.

D.3 Leak Test Methods:High-Pressure Refrigerants

There are several methods available forleak-testing equipment containing high--pressure refrigerants. These methods varydepending on the refrigerant charge andoperational status and are described in thefollowing paragraphs.

D-1


D.3.1 Operating Equipment withRefrigerant Charge

A positive-pressure refrigerant has suffi-cient pressure within all components of thesystem to enable most external leaks to theenvironment to be detected using leakdetectors. Use caution whenever leak-testing operating equipment due to thedangers associated with moving and rotat-ing parts. There is no method to directlydetect evaporator and condenser tube leakswith the equipment operating.

D.3.2 Idle Equipment withRefrigerant Charge

A positive-pressure refrigerant has suffi-cient pressure at all reasonable mechanicalroom or ambient air temperatures to enablemost external leaks to the environment tobe detected using leak detectors. There isonly one method to check for evaporatoror condenser tube leaks that use water asthe other heat transfer medium. It requiresthe equipment to be isolated from thewater piping, drain the tubes, and removethe tube sheet access plate. An eddy-curr-ent analysis or leak detector (electronic orultrasonic) can be used at this time tolocate leaks.

D.3.3 Equipment withoutRefrigerant Charge

There are situations in which leak-testingis necessary due to a loss of all refriger-ant, and it is inappropriate to pressurizethe system with refrigerant to ensure allleaks have been repaired. There are alsosituations where using the system refriger-ant pressure as the leak-producing mecha-nism may be inadequate to detect leaks.These situations may require the refriger-ant charge to be evacuated from the entire

system or a single component. When leak-testing a system or component which hashad the refrigerant removed:●

●

●

Do not use a chlorofluorocarbon (CFC)for a trace gas; use a hydrochloro-fluorocarbon (HCFC). HCFC-22 is themost commonly used trace gas. Injectthe trace gas into the system first,using as little as possible (four poundsmaximum) to minimize refrigerantemissions.Use compressed dry nitrogen to pres-surize the system. Never use com-pressed air, oxygen, or a flammablegas to pressurize the system! Thesystem may explode. Always use aregulator when adding nitrogen to asystem. Add nitrogen slowly, to allowbetter mixing with the trace gas andprevent sweeping the trace gas awayfrom the access port. To ensure thatthe rating of the relief valve is notexceeded, a maximum test pressure of200 pounds per square inch gauge(psig) is recommended.When possible, isolate and pressure-test only the part of the system thatrequires testing.

After a system is pressurized with nitro-gen, if possible, allow the system to standfor 12 to 24 hours to allow the tracer gasto disperse uniformly throughout the sys-tem. Once the tracer gas has dispersed,any of the methods described in sectionD.7 may be used to identify leak sources.

D.4 Leak Test Methods:Low-Pressure Refrigerants

To leak test equipment containing low-pressure refrigerants is more difficult than

D-2


high-pressure refrigerants. The methodsavailable are discussed in the followingsections.

D.4.1 Operating EquipmentThere is no way to completely leak-test alow-pressure refrigerant system duringoperation because a large part of the sys-tem is under a vacuum. The compressordischarge pipe, condenser, and pipingleading to the refrigerant flow controlvalve are all slightly above atmosphericpressure and can be checked using leakdetectors. Use caution when leak-testingoperating equipment due to the dangersassociated with moving and rotating parts.Evaporator and condenser tube leaks typi-cally involve water leaking into the refrig-erant, not the opposite. This is due to thelower refrigerant pressure in comparisonwith chilled and condenser water systempressures.

D.4.2 Off-Line Equipment TestingA thorough leak-check can be performedon a low-pressure refrigerant system onlywhen the system is not operating. Basemaintenance personnel should schedule amaintenance shut-down period of at least48 hours for a leak test. The timing of thistest should minimize the impact on thefacility’s mission served by the refrigera-tion system being tested. A leak check isnot a simple process, even with the equip-ment off-line. The refrigerant pressure inthe equipment will usually be under avacuum at room temperature. WithCFC-11, equipment is under a vacuumwhen the refrigerant temperature dropsbelow 23° C (74° F). With HCFC-123and CFC-113, equipment is under a

vacuum below 28° C (82° F) and 47° C(1 17° F), respectively.

D.4.2.1 The refrigerant pressure must beincreased above atmospheric pressure todetect leaks. Equipment containing refrig-erant can no longer be pressurized using anoncondensible gas such as dry nitrogen.The only method to increase the refrig-erant pressure above atmospheric pressureis to increase the temperature of the refrig-erant. In a constant volume system, thiswill cause a corresponding pressure in-crease. Increasing the temperature ofCFC-11 to 38° C (100° F) will produce a9 psig system pressure.

D.4.2.2 There are two pressure equaliza-tion system types used to increase refriger-ant temperature to obtain the desired pres-sure.

D.4.2.2.1 One system uses an electric-resistance blanket heater (commonly re-ferred to as a “belly heater”) with associat-ed temperature controls. The heatermounts on the underside of the evaporatorbetween the shell exterior and the insula-tion cover. The heat conducts through theshell and into the refrigerant.

D.4.2.2.2 The other system heats the re-frigerant by circulating hot water throughthe evaporator tubes. Using the servicevalves, the chilled water piping is isolatedfrom the equipment. There must be a hosebib or other valved connection on the inletand outlet chilled water piping connec-tions. These connections are used to circu-late the water in the evaporator through awater heater and back into the evaporator;

D-3

Appendix D – Refrigerant Leak Detection Methods and Equipment

the refrigerant temperature is raised, caus-ing the pressure to increase. The hot watersource can be permanent, portable, or thefacility’s domestic water heater.

D.4.2.3 Use caution when raising thetemperature of the refrigerant charge. Thepressure can not exceed the pressure reliefvalve and/or rupture disk setting. Thiswould cause refrigerant to escape to theatmosphere. Stop the addition of heat tothe refrigerant when a pressure of 8 to 10psig is achieved.

D.4.2.4 Perform a leak-check at all gas-kets, fittings, and penetrations, using theleak detection equipment or substancesdescribed later in section D.7.

D.4.3 Idle/Standby EquipmentA low-pressure system will usually be in avacuum at typical room or ambient tem-perature when it is not operating. Thiscauses any leakage to be air and watervapor into the chiller in lieu of refrigerantleaking out. The concern is this leakagerequires the purge unit to operate to re-move these gases and, in so doing, dis-charges refrigerant vapors. It is recom-mended that an integral pressure equaliza-tion system as described in D.4.2.2.1 andD.4.2.2.2 be used for refrigeration equip-ment which operates intermittently, espe-cially for equipment used largely for stand-by. This will control the pressure automat-ically, so its internal pressure is alwaysequal to the atmospheric pressure while thechiller is idle. This will minimize, if noteliminate, loss of refrigerant. Anotheroption is the removal of the refrigerantcharge for chillers that are idle for longdurations, such as a winter shutdown.

Refrigerant removed from the chiller willbe stored in a leak-tight tank capable ofwithstanding a range in pressure from 29.8inches of mercury vacuum to 15 psig.During this idle period the chiller shouldbe charged with dry nitrogen to a pressureof 1 to 2 psig to prevent moisture accumu-lation in the chiller vessels.

D.4.4 Equipment withoutRefrigerant Charge

There are two steps to leak test a low-pres-sure chiller without its charge. The firststep is to pressurize the system to allowthe leaks to be located and repaired. Uponcompletion, a vacuum is pulled to ensurethe equipment does not leak under itsnormal negative pressure operating condi-tions. These steps follow.

D.4.4.1 Step 1 - Pressurize the chillerwith dry nitrogen and use a soap-and-watersolution to check all joints. Leaks will berevealed by “bubbling” of the soap solu-tion. Repair all leaks discovered. If theleaks cannot be discovered, insert a fullyhalogenated HCFC refrigerant (one to fourpounds of HCFC-22) as a trace gas. Usean electronic halogen leak detector tolocate leaks. After the completion of thisprocedure, the mixture of HCFC-22 andnitrogen may be released to the atmo-sphere.

D.4.4.2 Step 2- Evacuate the chiller,using a vacuum pump capable of achieving1000 microns of mercury absolute. Onceevacuated to that level, allow the chiller tostand for 12 hours. Some pressure rise(due to microscopic leaks that cannot beprevented at reasonable cost) is acceptable.The Trane Company suggests if the pres-

D-4


sure does not rise above 2500 microns, theunit is acceptable and may be charged withrefrigerant. If the vacuum rises above2500 microns, the unit is unacceptable andfurther leak-testing is required. The pro-cedure in Step 1 should be repeated and,the vacuum pulled again.

D.4.5 Spectrographic Oil AnalysisRoutine spectrographic oil analyses willdetect the presence of moisture in therefrigerant circuit. The presence of mois-ture in the oil is indicative of the existenceof a leak source. This technique does notprovide indications as to the location ormagnitude of a leak. Detailed informationon spectrographic oil analyses is in Appen-dix F, Refrigerant Leak Mitigation throughEquipment Maintenance and Service Prac-tices, including recommended ceilingvalues for moisture in oil samples.

D.5 Potential Refrigerant LeakAreas

During inspections, leak-check certainleak-prone areas of the system for integri-ty. These areas include all penetrationsinto the refrigerant-occupying area and allnonwelded connections. Specific areasinclude:● motor terminals;● sight glasses;● shaft seals;● Schrader cores;● service, solenoid, and relief valves;● flare fittings;● joints with gaskets; and● filter dryers.Oil stains on positive-pressure equipmentor components are a sign of leak paths.

D. 6 Leak Detection EquipmentTerminology

The following terminology and criteriaassociated with leak detection allows eachtype of detection equipment to be com-pared with each other. These criteria areapplicable to both portable pinpointdetectors used for locating specific leaksources and permanently-mounted areamonitors used to sense a leak of refriger-ant within an enclosed area. These criteriaare sensitivity, detection limits, and selec-tivity.

D.6.1 SensitivityThe sensitivity of any device is defined asthe amount of input (material being mea-sured) necessary to generate a certainchange in output signal. For leak detec-tion, the material is the refrigerant vaporconcentration being measured and theoutput is the reading from a panel meter, avoltage output, or other display device.Detectors with good (high) sensitivityrequire very little material to generate alarge change in output signal, while detec-tors with poor (low) sensitivity requirelarger amounts of material to change theoutput signal. Sensitivity is affected by themethod of detection and the material beingdetected.

D.6.2 Sensitivity DifferencesThe sensitivity of an ionization detectorassociated with a particular material thatdemonstrates high sensitivity for CFC-12may have poor sensitivity for HCFC-123and very poor sensitivity for HFC-134a.The variations in sensitivity are due toreduction in chlorine content, very easily

D-5


ionized and detected, from CFC to HCFCto hydrofluorocarbon (HFC) compounds.Sensitivity differences of l00X to 1000Xhave been reported when comparingCFC-12 to HFC-134a with some ioniza-tion-based detectors. The impact of refrig-erant detection methods on sensitivity isillustrated in that an infrared (IR)-baseddetector will show roughly the same sensi-tivity to CFC-12, HCFC-123, andHFC-134a, which is not the case for anionization detector.

D.6.3 Detection LimitCertain analytical techniques have well-defined sensitivity values, but these do notexist for leak detectors. The most commonmeasure of how “sensitive” a detector canbe is the detection limit, defined as theminimum amount of material a unit cansense that gives a signal at least two timesthe background noise level. A sensitivedevice does not necessarily mean a lowdetection limit (it could have a high back-ground electronic noise level), although thetwo measures of performance usually tendto coincide. Detection limits for monitorsare measured in ounces per year for pin-pointing applications. Portable leak pin-pointers typically have detection limitsaround 0.25 ounces per year, although amore typical value is 3 to 4 ppm for mostcompounds. For example, a detector withhigh sensitivity may be able to accuratelydiscriminate concentration levels of 1 or 2ppm of vapor, while a low-sensitivitydetector may only be able to discriminatein increments of 20 ppm or higher.

D.6.3.1 Because sensitivity can varygreatly with different compounds, thedetector must be carefully matched to the

intended application. For example, anionization detector that claims a detectionlimit of 0.25 ounces per year for CFC-12does not work very well for HFC-134adetection. Conversely, an ionization detec-tor made specifically for HFC-134a maybe too sensitive for CFC-12 leak pinpoint-ing.

D.6.4 SelectivitySelectivity is defined as the ability todetect only the refrigerant of interest with-out interference from other compoundsthat may be present in the area. Selectivityis not too important for leak pinpointers,because the equipment is attempting topinpoint leaks, not determine the identityof the refrigerant. Based on selectivity as acriterion, electronic leak pinpointers canbe placed into one of the three categories:(1) nonselective, (2) halogen-selective, and(3) compound-specific.

D.6.4.1 Nonselective detectors detect anytype of emission or vapor present, regard-less of its chemical composition. Detectorsin this category are based on electricalionization, thermal conductivity, ultrason-ics, or metal-oxide semiconductors. Idealfor leak pinpointing applications, thesedetectors are simple to use, very rugged,inexpensive (normally, less than $500),and almost always portable.

D.6.4.2 Halogen-selective detectors use aspecialized sensor that allows the monitorto detect compounds containing fluoride,chloride, bromide, and iodide withoutinterference from other species. The majoradvantage of this detector is a reduction inthe number of “nuisance alarms”–falsealarms caused by the presence of

D-6

Appendix D – Refrigerant Leak Detection Methods and Equipment

non-refrigerant compounds such as paintand gas fumes. These detectors are easy touse, feature higher sensitivity than nonse-lective detectors (detection limits are typi-cally <5 ppm when used as an area moni-tor and <0.05 oz/yr when used as a leakpinpointer), and very durable. Due to thepartial specificity of the detector, theseinstruments can be calibrated easily.

D.6.4.3 Compound-specific detectors arethe most complex and expensive. Theseunits are capable of detecting the presenceof a single species without interferencefrom other compounds. Compound-specificdetectors are either IR-based or, as someof the newer types, infrared-photoacoustic-based (IRPAS). These normally havedetection limits around 1 ppm, dependingupon the compound being detected. Due torecent improvements in technology, theprice of compound-specific detectors hasdropped by about 50 to 60 percent duringthe last year. IR-based detectors can nowbe purchased for about $3,500 to $4,000.

D. 7 Leak Detection Methodsand Equipment

There are several methods available topinpoint leaks of refrigerant. They rangefrom simple soap bubbles to more complexelectronic detectors. Some detection meth-ods are invasive and must be injecteddirectly into the refrigerant. All the detec-tion methods have advantages and disad-vantages.

D.7.1 Ultrasonic Leak DetectorsUltrasonic leak detectors are nonselectiveand do not require the use of refrigerant todetect a leak. They employ an ultrasonic

method to listen for leaking gas. The gasmust be at a higher pressure than thelocation of the detector. The detectorcannot detect the sound of gas being pulledinto a vacuum.

D.7.1.1 This technique requires some ad-vance knowledge of the leak location and afairly low background noise level. Ultra-sonic leak detectors provide high sensitivi-ty adjustment. This type of equipment isreliable for outdoor use where air currentscan upset the accuracy of other methods ofdetection.

D.7.2 Electronic Leak DetectorsElectronic leak detectors can be obtainedin nonselective, halogen-selective, andcompound-specific styles. They require theuse of a fully-halogenated refrigerant as atrace gas. The most sensitive leak detec-tors used are ion source detector, thermis-tor type (based on change in temperature),and Dielectric type (measures a balance insurrounding air and then responds only tohalogen gas). These detectors can be diffi-cult to use in environments with highambient air velocities because the refriger-ant gases can be entrained in the airstreamand removed from the leak source beforebuilding up a detectable concentration.Finding the leak source can be made diffi-cult by airflows created by purge ventila-tion systems and condenser fans. Thesedetectors are effective at detecting smallleaks, as low as 1/2 oz/yr. A large leakmay saturate the element when using leakdetectors without a varying sensitivity.This situation will normally clear itselfwhen the instrument is removed from theatmosphere contaminated with refrigerantvapors.

D-7


D.7.3 Halide TorchesHalide torches are nonselective detectorsbased on the principle that alcohol, pro-pane, acetylene, and most other torchesbum with an almost colorless flame. Thistrait is further enhanced by the fact that ifcopper is placed in this flame, the flamewill continue to be almost colorless. How-ever, if even the tiniest quantity of a halo-gen refrigerant (for example, R-1 1, R-12,R-22) is brought into contact with thisheated copper, the flame will immediatelytake on a light green color. These detec-tors can be difficult to use in environmentswith high ambient air velocities becauserefrigerant gases can be entrained in theairstream and removed from the leaksource before building up a detectableconcentration. Finding the leak source canbe made difficult by airflow created bypurge ventilation systems and condenserfans. Some skill in discernment is re-quired, and bright sunlight makes them oflittle use outdoors. No sensitivity adjust-ment is available, thus these devices aresometimes unable to discern betweenrefrigerant concentrations in the generalarea versus a point source at the site of theleak.

D.7.4 Soap BubblesSoap bubbles are commonly used to detectleaks in equipment or components underpositive pressure. A water-soap solution issprayed or brushed over an area suspectedof leaking. Gas communing through thesolution will cause bubbles. The advantag-es of using the bubble method are its easeof use, low cost, and ease of application(compared to instrumentation). The bubblemethod can be used with a nitrogen-charged system and is also the best method

D-8

to be used when trying to check for a leakon a system that is located outdoors, wherethe wind may limit the use of any othertype of leak pinpointer. A disadvantage isthat larger leaks will blow through thesolution, and no bubbles will appear.

D.7.5 Fluorescent DyesFluorescent dyes are used in refrigerationsystems to detect leaks, invisible underordinary lighting, visible under ultraviolet(UV) light. Fluorescent dyes are availablefor all refrigerants in use today. The dyesare placed into the refrigeration lubricantwhen the system is serviced. Select a dyecompound compatible with the lubricatingoil in the refrigeration system. Contact therefrigerant supplier for recommendation onappropriate dyes to ensure compatibilitywith the refrigerant. Leaks are detected byusing a UV light to search for dye that hasescaped from the system. The color of thedye when subjected to UV light is normal-ly an easily-seen bright green or yellow.Fluorescent dyes work very well becauselarge areas can be rapidly checked by asingle individual.

D.7.6 Refrigerant DyeRefrigerant dye in a system will produce abright red color at the point of leakage. Toachieve maximum leak detection, theentire refrigerant charge must be replacedwith refrigerant containing the dye. Thepresence of dye in the refrigerant does notaffect the performance of the system.Refrigerant containing dye must be liquid-charged. This method of leak detectionpinpoints the leak where it occurs in thesystem. It is dependent upon the oil circu-lation rate and can take time to indicateleaks.


Table D-1. Comparison of Leak Detectors

Comments Nonselective Halogen-Selective Compound-Specific Fluorescent Dyes

Advantages: ● Simplicity ● Simple/rugged ● Virtually ● Low price● Ruggedness ● Can be calibrated interference-free ● Rapid detection

● Good sensitivity ● Can be calibrated ● Interference-free● Low maintenance ● Good sensitivity

Dis- ● Poor detection ● Not compound- ● Complexity/ ● Potential lubricantadvantages: limits specific maintenance compatibility

● Cross-sensitive ● Detector lifetime/ ● Stability problemsto other species stability questionable ● Difficult to use in

● Most cannot be direct sunlightcalibrated

Refrigerants ● All CFCs ● All CFCs ● Not recommended ● All currentlyDetected: ● HFC-134a ● All HCFCs due to high price available

● HCFC-123, blends ● HFC-134a, blends refrigerants

D.7.7 Visual Equipment Inspection D. 8 Vendor ListingIn many cases, a refrigerant leak can belocated with a visual inspection. Whenrefrigerant escapes from a sealed system,lubricating oils are usually entrained withthe refrigerant vapor. This oil will, inmany cases, leave art oily residue on thepiping and equipment in the immediatevicinity of the leak. While this is a crudemethod, it can often be used to localizesuspect components, allowing a moredefinitive search with one or more of theaforementioned techniques. Often the lossof as little as one pound of refrigerant willresult in the deposition of a noticeable oilresidue.

D.7.8 ConsiderationsThere are several items which should beconsidered when selecting leak pinpointingequipment. Table D-1, Comparison ofLeak Detectors, provides a general check-list to ensure items are not overlooked.

A partial listing of-companies that produceleak detectors follows. These companiesare not recommended or endorsed by theAir Force.

D.8.1 Nonselective DetectorsThermal Gas SystemP.O. Box 803Roswell, GA 30075(404) 667-3865

D.8.2 Halogen-Selective DetectorsLeybold-Inficon, Inc.Two Technology PlaceEast Syracuse, NY 13057(315) 434-1246

SenTech CorporationP.O. Box 429052020 Production DriveIndianapolis, IN 46242(317) 248-1988

D-9


Yokogawa Corporation of America2 Dart RoadShenandoah Industrial ParkNewnan, GA 30265-1094(800) 447-9656

D.8.3 Compound-Specific DetectorsFoxboro CorporationEMO Division, P.O. Box 500600 N. Bedford StreetEast Bridgewater, MA 02333(508) 378-5400

Gas Tech, Inc.8407 Central AvenueNewark, CA 94560(510) 794-6200

D.8.4 Fluorescent DyesSpectronics Corporation956 Brush Hollow RoadP.O. Box 483Westbury, NY 11590(800) 274-1988

D-10

Appendix E – Equipment to Reduce Refrigerant Release During Maintenance and Operation of AC/R Systems

Appendix E — Equipment to Reduce Refrigerant ReleaseDuring Maintenance and Operation of

Air Conditioning and Refrigeration Systems

ABSTRACT This appendix discusses the equipment available to reduce refrigerant releaseduring operation and servicing. It addresses the Environmental Protection Agency (EPA)requirements for re-use of refrigerant removed from air conditioning and refrigeration (AC/R)equipment.

E. 1 Introduction

EPA requires AC/R equipment owners andmaintenance technicians to implementcertain practices to minimize refrigerantloss. This appendix discusses equipmentthat can be added to AC/R equipment orused by maintenance technicians servicingthe equipment to meet these requirements.It explains the EPA performance require-ments for the equipment. It addresses theEPA requirements for re-use of refrigerantremoved from AC/R equipment.

E.2 Recovery and RecyclingEquipment

Recovery equipment must meet certainevacuation standards to minimize refriger-ant losses during service that requiresopening the refrigeration system. EPA isgrandfathering equipment manufactured orimported before 15 November 1993, aslong as it meets the evacuation require-ments listed in Table E-1, Required Levelsof Evacuation for Appliances Except forSmall Appliances, MVACS, and MVAC-Like Appliances. Currently, there areno requirements to retrofit or replace

grandfathered equipment. Recovery andrecycling equipment manufactured orimported on or after 15 November 1993must be tested and certified by a third-party, EPA-approved testing laboratory ororganization. EPA is requiring verificationof performance for vapor recovery effi-ciency and efficiency of noncondensiblepurge devices on recycling machines. Allcertified recycling and recovery equipmentmust have a manufacturer’s or importer’slabel indicating that it was certified andshowing who certified the equipment (seeAppendix A, Update on Refrigerants:Translating the Laws, Regulations, andPolicies into Practice). Equipment manu-factured or imported after 15 November1993 must meet the evacuation require-ments listed in Table E-1.

E.2.1 Evaluation CriteriaMany manufacturers offer a variety ofrecovery equipment. In making an in-formed choice, consideration should begiven to:● safety, including cutouts for high pres-

sure, low pressure, and high tempera-ture;

● Underwriters Laboratory (UL) approv-al;

E-1

Appendix E — Equipment to Reduce Refrigerant Release During Maintenance and Operation of AC/R Systems

Table El. Required Levels of Evacuation for AppliancesExcept for Small Appliances, MVACS, and MVAC-Like Appliances1

Inches of Mercury Vacuum”Using Equipment Manufactured:

Before On or AfterType of Appliance 15 Nov 1993 15 Nov 1993

HCFC-22 appliance- normally containing less than 200 0 0pounds of refrigerant

HCFC-22 appliance” normally containing 200 pounds 4 10or more of refrigerant

Other high-pressure appliance- normally containing less 4 10than 200 pounds of refrigerant(CFC-12, -500,-502, -144)

Other high-pressure appliance- normally containing 200 4 15pounds or more of refrigerant(CFC-12, -500,-502, -144)

Very high-pressure appliance (CFC-13, -503) o 0

Low-pressure appliance (CFC-11, HCFC-123) 25 29

* Relative to standard atmospheric pressure of 29.9" Hg** Or isolated component of such an appliance1 Federal Register, Vol. 58, No. 52, Friday, May, 1993, pg. 28

● maintenance requirements (that is,number of parts requiring replacement,the recommended frequency of replace- ●

ment, and cost);● versatility in meeting different job

functions; E.

with tanks supplied by its manufac-turer; andif the unit is equipped with low-lossfittings.

3 Recovery, Recycle, and● the cylinder or tank capacity holding Reclaim- Definitions

the refrigerant while work is beingdone on the refrigeration system; The process of removing refrigerant from

● recovery rate of the equipment (should a refrigeration system is recovery. Whenbe such that the total charge can be equipment operation indicates contamina-recovered in one hour maximum); tion or refrigerant deficiency, refrigerant

● price of filter replacements; can be recovered and recycled on-base. If● whether the unit uses interchangeable contamination is severe, or exacting stan-

storage tanks or can it be used only dards must be met, refrigerant must be

E-2

Appendix E – Equipment to Reduce Refrigerant Release During Maintenance and Operation of AC/R Systems

reclaimed off-base. Once refrigerants arecontaminated or mixed, complicated proce-dures must be used for separation. Recla-mation by refrigerant distillation can sepa-rate some refrigerants. If the refrigerant iscontaminated such that it cannot be sepa-rated by distillation, it must be sent to anauthorized treatment facility for disposal.

E.3.1 RecoveryRecovery is the act of removing refriger-ant, in any condition, from a refrigerationsystem in either an active or passive man-ner, arid storing it in an external container.Recovery is mandatory if the system is tobe opened to the atmosphere. If an equip-ment component that requires work can beisolated, then only the isolated section ofthe equipment needs to be evacuated.Internal refrigerant storage should be usedat every opportunity.

E.3.2 RecyclingRecycling is the act of reducing contami-nants in the recovered refrigerant by oilseparation with single and multiple passesthrough devices such as replaceable filtercore driers. These devices reduce mois-ture, acidity, and particulate matter. Recy-cling can be advantageous for dryingrefrigerants that contain moisture (notwater) or removing particulate.

E.3.3 ReclamationReclamation is the act of purifying, test-ing, and certifying used refrigerant to newproduct specifications by means whichmay include distillation. Chemical analysisof the refrigerant is required to assure thatappropriate product specifications are met.Reclamation of refrigerants from a systemthat is in the process of repairs (in most

cases) is not required. It is mandatory iffree water is standing in the system (forexample, such as a tube failure) or ifmotor bum-out has occurred. Refrigerantsrecovered from equipment are required tobe reclaimed if they are being transferredto a new owner (a different base is notconsidered a new owner).

E.4 Low-Loss Fittings

EPA defines in 40 C.F.R. Part 82 (1993)a low-loss fitting as any devicethat is intended to establish a connectionbetween hoses, air-conditioning and refrig-eration equipment, recovery or recyclingmachines, and is designed to close auto-matically or manually when disconnected,minimizing the release of refrigerant fromhoses, air-conditioning or refrigerationequipment, and recovery or recyclingmachines. EPA requires that recovery orrecycling machines manufactured orimported after 15 November 1993 possesslow-loss fittings. It is recommended thatlow-loss fittings be added to refrigerationequipment connection points and serviceequipment hoses.

E.5 High-Efficiency PurgeUnits

Purge units are used with low-pressurechillers and refrigerant recovery equipmentto remove noncondensibles that may enterthe system. Traditional purge unit designscan expel large amounts of refrigerant.High-efficiency purge units allow noncon-densibles to be vented while releasingrelatively small quantities of refrigerant.There are two levels of high efficiency:(1) one group discharges approximately

E - 3


0.7 to 1.0 pounds of refrigerant per poundof noncondensibles, and (2) ultra high-efficiency units discharge 0.0005 poundsof refrigerant per pound of noncondens-ibles. With the discharge information, run-time, and amount of refrigerant and non-condensibles processed per unit time, themaintenance technician can determine therun-time needed to cause refrigerant lossesin excess of EPA limits. Choose a purgeunit that contains a safety system toprevent excessive purging due to malfunc-tion or a large leak. These safety systemslimit the time that a purge unit may oper-ate to assure that a control malfunctionwill not allow the purge unit to operatecontinuously.

E.5.1 Low-Pressure Chiller Purge UnitsEPA has not established any requirementsfor chiller purge units. However, AirForce policy is to replace older purge unitswith new, high-efficiency purge unitsequipped with run-time meters.

E.5.2 Recycling Equipment Purge UnitsEPA has established the maximum purge-10ss limit for recycling equipment purgeunits at five percent of the total refrigerantbeing recycled. As of 15 May 1995, thepurge-loss limit will be reduced to threepercent of the total refrigerant being recy-cled.

E.5.3 Servicing Purge SystemsMost purge systems require regular ser-vice. Purge tanks and oil separators mustbe cleaned, gasket materials must be re-newed, purge compressors must beoverhauled, and so forth. These functionsshould be conducted in accordance withthe purge system manufacturer’s guide-lines. To open the purge system for

service, isolate it from the chiller refriger-ation system and recover the refrigerantfrom the purge unit. To provide a conve-nient, efficient means of accomplishingthis on an ongoing basis, permanent accessand isolation valves should be installed inthe system when the new high-efficiencyunit is

E. 6

installed.

Low-Pressure SystemsPressurization Methods

Low-pressure systems can be under avacuum when they are not in operation.Their purge systems remain in operation tokeep air and moisture out of the system. Ifthe machine leaks, it will cause the purgeto operate more often, discharging refrig-erant along with noncondensibles. Theinstallation of a pressurization system cansolve this problem. There are two types ofsystems, blanket heater and water heat-er/pump, both operating on the principleof increasing system pressure through theaddition of heat to the refrigerant.

E.6.1 Blanket HeaterThe most common pressurization system isan electric-resistant blanket heater installedbetween the outer shell of the evaporatorand its insulation, jacket. Because it ismounted on the underside of the shell, it iscommonly known as the “belly” heater. Ablanket heater is used to prevent refriger-ant air infiltration by heating the refriger-ant until the pressure is at or nearly atatmospheric. The blanket heater also canbe used to raise the system pressure aboveatmospheric pressure to allow leak testing.Typically, temperature or pressure sensorsmonitor the condenser conditions and are

E-4


used to control the blanket heater. Toprevent system over-pressurization andsubsequent loss of refrigerant, the accura-cy of temperature or pressure sensorsshould be checked prior to energizing theblanket heater.

E.6.2 Water Heater/PumpThe second type of system uses a smallelectric water heater and circulating pumppackage. It heats and circulates waterthrough the evaporator tubes to raise therefrigerant temperature and, consequently,the system pressure. Prior to initiating theheating process the evaporator should beisolated from the distribution piping sys-tem. The heat addition to the water istypically controlled by monitoring thewater temperature once it has exited the

evaporator. To prevent system over-pres-surization and subsequent loss of refriger-ant, the temperature sensor should bechecked prior to starting the water heat-er/pump system.

E. 7 Re-Use of RecoveredRefrigerants

EPA allows refrigerant remaining on-siteto be returned to AC/R equipment ortransferred between equipment owned bythe same entity with or without beingrecycled or reclaimed. Refrigerant chang-ing ownership must be reclaimed toARI 700-88. This standard requires achemical analysis to verify the purity ofthe refrigerant before it can be re-used.

E-5 (E-6 Blank)


Appendix F — Refrigerant Leak Mitigation through Equipment Maintenance and Service Practices

Appendix F — Refrigerant Leak Mitigation throughEquipment Maintenance and Service Practices

ABSTRACT: This appendix addresses refrigerant leak mitigation through equipmentmaintenance and service practices. The Environmental Protection Agency (EPA) has severalrequirements and recommendations to reduce, if not eliminate, refrigerant loss when maintainingor servicing equipment. These include major changes from the methods used in the past. Thenew methods are more rigid and tasks will require more time to complete. Personnel who install,service, or repair refrigeration equipment must be certified.

F.1 Background

Many preferred refrigeration service andmaintenance practices commonly used inthe past resulted in the routine release ofsignificant quantities of refrigerant to theatmosphere. EPA has promulgated newregulations in response to Clean Air ActAmendments (CAAA), Title 6, which areintended to force changes in these practicesto minimize the loss of refrigerant. Thesenew laws and regulations have seriousimplications for air conditioning and re-frigeration (AC/R) owners, operators, andmaintenance personnel.

F.1.1 Technician TrainingThe training of chiller operators and main-tenance and service personnel is the firstline of defense for minimizing refrigerantloss. Service and maintenance personnelshould be familiar with procedures tominimize refrigerant emissions, the use ofnew safety equipment, and techniques forproper refrigerant handling.

F.1.2 Technician CertificationAny person who performs maintenance,service, or repair to AC/R equipment thatcould reasonably be expected to releasechlorofluorocarbons (CFCs) or hydro-chlorofluorocarbons (HCFCs) into theatmosphere must be certified. Performanceof these duties by improperly trainedpersonnel can waste valuable refrigerantand result in violation of the law.

F.1.2.1 EPA requires certification of allindividuals who maintain, install, service,or repair AC/R equipment. It has estab-lished four categories of technician certifi-cation associated with the ability to handleand service refrigerants and associatedequipment. Three of these categories arefor specific types of equipment. The fourthis an universal category. Technicians mustbe certified by an EPA-approved certifyingorganization by 14 November 1994. Formore information see Handbook, Chap-ter 2, Conservation Efforts for the BaseRefrigerant Management Program, and

F-1


Appendix A, Update on Refrigerants:Translating the Laws, Regulations, andPolicies into Practice.

F.2

Much

Minimizing Maintenanceand Service Emissions

refrigerant has been lost in pastyears due to the methods of maintainingand servicing equipment. ASHRAE Guide-line 3-1990 states: “Significant loss ofrefrigerant can be attributed to improperoperation and monitoring of equipmentoperation. Routine operating logs shouldbe kept so that the operator (or technician)knows how much refrigerant and oil areused. ” The WIMS Refrigerant Manage-ment Software provides the capability tocollect and organize maintenance andoperating data for all refrigeration sys-tems. The use of this system to replace theexisting “paper” maintenance and opera-tion logs will enhance the ability of a basemaintenance crew to spot adverse trendsand predict future refrigerant needs.

F.2.1 Service PracticesCurrent service practices revolve aroundcontainment of refrigerant within the sys-tem. For example, venting refrigerants tothe atmosphere is now illegal. It cannotimpact the environment if contained. Ser-vice practices which keep refrigerantsisolated from the environment as much aspossible are now required. The followingpractices are now banned by the CAAA.● Blowing vapor charge after removal of

liquid when opening equipment.● Refrigerant drums open to the atmo-

sphere.● Using refrigerants as cleaning solvents.

● Leak-testing with nitrogen if the systemcontains its refrigerant charge. Leaktesting with a trace gas, HCFC-22, ispermitted; see Appendix D, RefrigerantLeak Detection Methods and Equip-ment. (This will potentially contami-nate the refrigerant charge with non-condensible gases which will subse-quently require purging, thus resultingin an additional loss of refrigerant.)

● Operating systems in under-charged orover-charged modes.

● Changing oil filters at intervals morefrequently than required by manufac-turers’ recommendations or as indicat-ed by spectrographic oil analyses.

F.2.1.1 EPA requires low-pressure sys-tems undergoing minor servicing, such asoil changes, to be pressurized to atmo-spheric pressure to minimize the intrusionand subsequent purging of air. Methods,such as heat, that do not require subse-quent system purging must be used.

F.2.1.2 Purge run-time should be moni-tored. Many manufacturers suggest thatpurge systems operating in excess of onehour of run-time per week are indicativeof excessive leakage.

F.2.1.3 Purge systems require regularmaintenance and service to ensure properoperation. Purge tanks and oil separatorsmust be cleaned, gasket material renewed,and purge compressors overhauled. Thesetasks must now be performed with little orno loss of refrigerant by installing perma-nent access and isolation valves on the unitto service it with minimal emissions.These valves should be installed the next

F-2


time the machine is serviced. When servic-ing the purge unit, the liquid and vaporrefrigerant must be evacuated prior toopening it to the atmosphere.

F.2.1.4 Specified high-efficiency purgeunits should be evaluated as:● replacements for older, less efficient

units on existing chillers, or● new equipment on replacement chillers.Some of the high-efficiency purge unitscurrently on the market include high main-tenance components like floats and regulat-ing valves. Additional maintenance re-quirements should be considered in thespecification development process forpurge systems. See Appendix E, Equip-ment to Reduce Refrigerant Release DuringMaintenance and Operation of Air Condi-tioning and Refrigeration Systems, formore information on purge limits.

F.2.1.5 Oil should not be changed on anarbitrary schedule; instead, oil samplesshould be analyzed on a regular, scheduledbasis to check for contamination. Thisanalysis should determine the necessity foran oil and filter change. These tasks mustnow be performed with minimal refriger-ant loss. An oil sample port and isolationvalves should be installed around the filterat the first service opportunity.

F.2.1.6 Isolation valves for all equipmentsub-components should be installed to iso-late them for service and repair. Replacemissing system connection and refrigerantcylinder caps and ensure the seal is ingood condition. Using a Schrader corereplacement tool will allow the replace-ment of a leaking Schrader core without

having to open the system or isolate therefrigerant charge.

F.2.1.7 Refrigeration gauge sets shouldbe rebuilt with new seals, valve seats, andpacking to minimize refrigerant losses.Additional features that will further mini-mize refrigerant loss include:● quick-connect fittings on hoses;● four-valve manifolds to minimize the

amount of hose and manifold refriger-ant purging;

● quality, high-strength hoses to preventpossible rupture; and

● separate refrigeration gauge sets foreach refrigerant to avoid cross contam-ination.

F.2.1.8 Equipment service requiringremoval of the refrigerant charge can bedone with either a pumpout (active) or apump-down (passive) method.

F.2.1.8.1 The pumpout method is themost common for system refrigerant re-moval. It uses a self-contained recoveryunit, often referred to as a recovery/re-cycling machine. These machines arecapable of both liquid and vapor removal.It is best to remove as much of the refrig-erant in a liquid form as possible. Theequipment removes liquid at a much higherrate than that for vapor. The vapor chargemust then be removed using the recoveryunit. The system or isolated section mustbe evacuated to the level shown in TableE-1, Required Levels of Evacuation forAppliances Except for Small Appliances,MVACS, and MVAC-Like Appliances. Ahigher ambient temperature also facilitatesmore rapid recovery due to increasedsystem internal vapor pressure.

F-3


F.2.1.8.2 The pump-down process is pre-ferred. It uses the refrigeration system’scompressor to remove the refrigerant froma component and move it to an integralreceiver or another component of thesystem where it can be stored duringmaintenance. The isolated section must beevacuated to the level shown in Table E-1,Required Levels of Evacuation for Appli-ances Except for Small Appliances,MVACS, and MVAC-Like Appliances.

F.2.1.9 All preventative maintenancework plans should be modified to includeleak-checks of leak-prone areas of thesystem. Be assured that a brazed or weldedfitting will develop leaks. The followingitems should be checked regularly:● flanges and gaskets,● screwed piping at connections,● compressor seals,● deteriorated O-rings,● valves and cylinders,● missing valve caps,● purge system leaks,● receiver leaks,● flare fittings,● Schrader cores, and● sight glasses.

F.2.1.10 Certified technicians shoulddetermine the type of service work re-quired before opening the system. Previousservice records obtained from the WIMS,or operating logs, can provide backgroundon the equipment. This information can beused to develop a work plan which willensure that refrigerant losses are held tominimal levels.

F.3 Spectrographic Oil Analysis

Laboratory analysis of chiller oil is amethod of analyzing the mechanical condi-tion of equipment and pinpointing whentear-down and visual inspection is needed.A spectrographic oil analysis is inexpen-sive and usually has a quick turnaround.The cost ranges from $50 to $150 peranalysis. An analysis should be performedfor comfort cooling applications twice eachyear or every 2,000 to 2,500 hours ofoperation. Prior to taking a sample of theoil for analysis, a chiller must be in opera-tion at least one hour. Otherwise, anymetals that might be in the oil will nothave had sufficient time to be re-entrainedfrom the bottom of the machine and willnot be detected by the analysis. Withcomplete and accurate laboratory oil analy-sis testing, recommendations for appropri-ate action become more reliable.

F.3.1 Particulate EvaluationThe oil filter is also an important source ofinformation. Just as technicians can spotdebris trapped on the falter material, thelaboratory can identify these sediments tofurther evaluate system condition. Thisevaluation can be just as important as thetesting of the liquid oil sample.

F.3.2 Sources for Laboratory AnalysisThe following laboratories, as of the dateof this document, are capable of perform-ing an oil analysis which will indicatemoisture, acid, and various metals content.Only TAI Services and Trane Service Firstare familiar with equipment oil analysis

F-4


and, therefore, provide an analysis of thedata. The Air Force does not endorse anyof the following laboratories; the list isprovided for information purposes only.

Advanced Chemistry Labs3039 Amwiler Rd., Suite 100Atlanta, GA 30360(404) 409-1444

Southern Petroleum Labs8820 Interchange Dr.Houston, TX 77054(713) 660-0901

TAI Services Inc.1900 Lake Park Dr., Suite 300Smyrna, GA 30080-88741-800-554-4127

Trane Service First4500 Morris Field Dr.Charlotte, NC 28208(704) 398-4600

F.3.3 Analysis ReadingsInformation received from a laboratoryanalysis of chiller oil should include:● water suspension,● viscosity,● total acid number (TAN),● dielectric strength,● color, and● interracial tensionand an assessment of the condition of theequipment based on these analyses.

F.3.3.1 The amount of water suspendedin a lubricant is measured in parts per mil-lion (ppm). Water content in the chiller oilsample should not exceed 40 ppm for

reciprocating systems and 50 ppm forcentrifugal and rotary screw systems.

F.3.3.2 The viscosity, reported in centi-stoke (cSt) at 40° C (1120 F), measures afluid’s internal resistance to flow at agiven temperature in relation to time.Change in viscosity can indicate dilution,oxidation, improper servicing, or lubricantbreakdown.

F.3.3.3 The TAN indicates the amount ofacidic product present in a lubricant. Gen-erally, an increase in TAN, above that ofthe new product, indicates oil oxidation orcontamination with an acidic product.Total acid should not exceed 0.150 mgKOH per gram of oil sample.

F.3.3.4 The dielectric strength measuresthe insulating ability of a fluid. A lowvalue can indicate the presence of water orother conducting compounds.

F.3.3.5 Visual determination of a fluid’scolor serves as an indicator of the presenceof contaminants and system operatingconditions.

F.3.3.6 The analysis of interracial tensionis an indicator of the presence of com-pounds with a strong affinity for water.

F.3.4 Analysis of Metal ContentThe spectrographic analysis of chiller oilwill show the metal content within the oiland should indicate possible sources of thatparticular metal. Typical elements discov-ered in analyses and their available sourcesare listed below.

F - 5


Element Possible SourcesIron Shell/supports/

cylinder/tube sheetChromium Rings/cylinder/crankshaftNickel Tubes/crankshaftAluminum Pistons/bearings/impellerLead/Tin BearingsCopper Bearings/tubes/oil linessilver Solder/coolerSilicon Dirt/sealant/coolantBoron Additive/coolantSodium Brine/coolantPotassium AdditiveZinc Anti-wear additiveCalcium/Magnesium Brine/detergent additiveBarium Detergent additive

The results of all oil analyses should bepreserved in historical maintenance files.In many cases, rapid changes in valuesmay be more indicative of problems thanthe magnitude of the value at any givenpoint in time. In fact, the real strength ofspectrographic analysis is the ability tospot excessive wear rates of given compo-nents shown by rapidly increasing concen-trations of the elements listed above inrelation to operating hours between sam-ples. To properly spot these trends, theanalytical laboratory performing the testsmust be supplied with previous test data.

F.3.5 Disposing of Contaminated OilFederal, state, and local regulations mustbe followed in the disposal of contami-nated oil. Per 40 C.F.R. section 261.3(1993), used refrigerant oils are not classi-fied as hazardous wastes, providing thefollowing conditions exist:l used refrigeration oils are not mixed

with other hazardous wastes;● used refrigeration oils will be recycled

or reclaimed for future use;

● used refrigeration oils are not mixedwith used oils from other sources; and

● used refrigeration oils do not containany contaminants, such as heavy met-als, which will render it a characteris-tic waste when analyzed using theToxicity Characteristic Leaching Proce-dure per 40 C.F.R. section 261.24(1993).

F.3.5.1 It is the responsibility of the gen-erator of a potentially hazardous waste todetermine whether a material should beclassified as a hazardous waste. Local andstate codes may be even more stringentthan federal regulations. Therefore, baseenvironmental officers should be consultedprior to disposing of any potentially haz-ardous waste.

F.3.5.2 When an oil analysis indicatesthat the refrigerant oil should be replaced,care should be taken to avoid the atmo-spheric release of refrigerant which maybe in solution in the oil. This can be ac-complished by pumping the oil into asealed, reusable container. A refrigerantrecovery system can then be used to pull avacuum on the head space above the oil inthis container. This configuration willcause the refrigerant to “outgas” from theoil. The out-gassed refrigerant will then becaptured by the refrigerant recovery sys-tem. This recovered refrigerant can thenbe returned to the refrigeration system orplaced in proper storage containers. In nocase should refrigerant oil be pumped intoa vented container allowing the uncon-trolled loss of refrigerant to theatmosphere.

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F.4 Chiller Tube-Testing

A vital element of a successful preventivemaintenance program that minimizes emis-sions is a regularly scheduled chiller tube-testing program. It prevents refrigerantcontamination caused by tube rupture,ensures tube integrity and efficiency, andcan provide early warning.

F.4.1 Eddy Current Tube-TestingEddy current tube-testing is a method thatmeasures the thickness of the tube as theprobe passes from one end to the other.This method can identify potential leakareas before they occur and prevent un-scheduled chiller downtime, lost produc-tion or cooling, major chiller damage, andcontamination of the refrigerant charge.Refrigerant contaminated by water in-leakage will require reclamation. To pro-tect the refrigerant charge, eddy currenttube-testing should be performed at leastevery three years for a chiller. This analy-sis, if performed by an outside contractor,costs approximately $1,500 per analysis.An eddy current tube-testing device can bepurchased from most refrigeration equip-ment suppliers for $20,000 to $30,000.

F.5 Additional EPARequirements

The EPA requires equipment service andrefrigerant usage records to be maintainedfor three years. This applies to all comfortcooling and refrigeration equipment withan operating charge of 50 pounds orgreater.

F.5.1 Recordkeeping Satisfiedwith WIMS

The WIMS Refrigerant Management Soft-ware can provide the refrigerant usage andservicing history for each piece of equip-ment as required by EPA. It will alsomonitor the progress of the Base Refriger-ant Management Program (BRMP) bytracking refrigerant inventory and con-sumption. Information of the use of theWIMS Refrigerant Management Softwarecan be found in Appendix G, Work Infor-mation Management System (WIMS).

F.5.2 Repairing LeaksCommercial refrigeration equipment withover 50 pounds of refrigerant (for exam-ple, cold storage plants) must be repairedof all leaks within 30 days if the equip-ment is leaking at a rate which will exceed35 percent of the total charge during a12-month period. Equipment, other thancommercial refrigeration, containing 50 ormore pounds of refrigerant (for example,comfort cooling) must be repaired of allleaks within 30 days if the unit leaks at arate exceeding 15 percent of the totalcharge during a 12-month period. Equip-ment does not require repair if, within 30days after leak identification (as describedabove), a plan is developed for retirementwithin one year. A copy of the plan mustbe available at the site of the equipment.Some state or local regulations, codes, andordinances may impose more stringentrequirements than the EPA regulations.Therefore, base environmental officersshould be consulted prior to electing acourse of action to either repair a leak orreplace a piece of equipment.

F-7 (F-8 Blank)


Appendix G – Work Information Management System (WIMS)

Appendix G — AFCESA Work InformationManagement System (WIMS)

Software Release 940715

ABSTRACT: This appendix explains the Work Information Management System (WIMS)and, specifically, the WIMS Refrigerant Management Software. It explains how to use thesystem to help the base Refrigerant Manager (RM) and technicians implement the RefrigerantManagement Plan (RMP).

G. 1 Refrigerant ManagementSystem Overview

G.1.1 Purpose of SoftwareThe Refrigerant Management System(RMS) program (module) is made up ofseveral submodules designed to provide theBase Civil Engineer (BCE) with a mean-ingful way to manage refrigerationequipment and refrigerant supplies. TheRefrigerant Management System sub-modules are listed below and discussed indetail in their individual sections:●

●

●

●

Refrigeration Equipment Inventory(MREQUD)Refrigeration Equipment Service(MRESUD)Refrigerant Bench Stock Adjustment(MRTRUD)Upward Reporting Data Log(MRURUD)

The Refrigerant Management System isdesigned to aid the Refrigerant Manager(RM):●

●

●

Track refrigerant consumption forindividual pieces of equipment;Monitor refrigerant inventories;Prioritize equipment repairs.

and,

When used correctly, these applicationswill fulfill the Environmental ProtectionAgency (EPA) requirements to recordservice data on units using chlorofluoro-carbons (CFCs) and hydrochlorofluoro-carbons (HCFCs).

G.1.2 Special Features

G.1.2.1 User’s InterfaceThe module’s user interface has beenaltered from the standard WIMS interface.When adding transactions, an equipmentitem selection (directory) screen is dis-played instead of a detail screen. When arecord has been selected, all necessaryequipment information will be automatical-ly entered by the program onto the detailscreen. This reduces typing.

G.1.2.2 Input Data ValidationNumerous information validation checksare performed to ensure meaningful datawill be collected. For example, whenentering a new transaction, the RefrigerantQuantity file must contain a numericvalue. The transaction will not be ac-cepted if the value is greater than theequipment item’s capacity.

G-1


G.1.2.3 Selectable FieldsSome data fields are selectable fields toprevent invalid entries. These selectorscontain lists of valid terminology that canbe chosen for a particular field. Place thecursor on the data field, press PF14(Select) and the selector list will display.Place the cursor next to your choice, placean X in the blank, and press ENTER tocommit the selector choice.

G.1.2.3.1 Selectable data lists are a safetyfeature to prevent invalid entries in thedata field while ensuring system-wideconsistency of terms. These selector filescontain validation lists that prevent mis-spellings, provide up-to-date lists ofequipment, consistently used abbreviations,and other terminology or lists that shouldbe static throughout the entire program.

G.1.2.3.2 Some selectors are neithermodifiable nor transactable by the bases orMAJCOMs.

G.1.2.4 Archiving (PF28)The data from this application should bearchived two years from the date it wasentered, When the application is firstbrought on the screen, the module isreviewed for records two or more yearsold. If they exist, the program will inform

the user that records should be archived.

G.1.2.5 Equipment StatusThe Equipment Status field will initiallyreflect the current status per the EquipmentInventory file. If the Status is modifiedon this screen, the Equipment Inventorysubmodule will be updated automatically.

G.1.2.6 Data Reporting RequirementsThe software allows data to be upwardreported to HQ AFCESA/EN through theMAJCOM. PF27 is used by the base andMAJCOM RMs to upward report newtransactions to HQ AFCESA/EN. Thiskey will be displayed only after refrigerantservice records have been input. Datamay not be modified by either HQAFCESA or the MAJCOM. This data isused for trend analysis only. Upwardreporting should be accomplished by thetenth working day following the end ofeach quarter.

G.1.2.7 SecurityThe access to change information through-out the Refrigerant Management System isgranted through the Generic User Rightssystem (IRGTUD). Listed below are therights that can be granted to users of theRefrigerant Management System (RMS) atthe discretion of the Base Civil Engineer-ing’s (BCE) Refrigerant Manager (RM).

Add (PF11)

Modify (PF9)

Delete (PF12)

Upward Reporting(PF27)

Archive (PF28)

Allows the user to add records to the data file.

Allows the user to modify existing records in the data file.

Allows the user to delete existing records from the data file.

Allows base level users to transmit Refrigeration Manage-Management System transactions to their MAJCOM, andMAJCOM users to transmit the latest base level records to HQAFCESA/EN.

Allows the user to archive records that are over two years old.

G-2


Note: There may be variations in which G.2 Main Menuuser rights are granted to each user.Some user rights (modify or delete) bear The Refrigerant Management Systema great deal of responsibility and care (RMS) main menu (Figure 1) lists allmust be taken to issue only those rights submodules in the system, and all reportsnecessary to individual users. that can be developed in these submodules.

HQ Air Force Civil Engineering Support Agency Tuesday 94/06/14 01:21 PM * 1** 2*

Hello : Mr Rich Bauman ENB * 3*MREFR : Refrigerant Management System - Version 93/11/03 899 * 4*

* 5 *To Select a Function Press (PFKEY) or Position Cursor and Press (ENTER) * 6 *

* 7*(1) * Refrig Equipment Serviced Service Reports: * 8*

(18) * Refrig Service Log Report * 9 *(3) * Refrig Bench Stock (19) * Refrig Consumption Report *10*

* 1 *

(5) * Refrig Equipment Inventory* 2 *

Refer Inventory Reports: * 3 *(22) * Refrig Bench Stock Report * 4 *(23) * Refrig Quantities Report * 5 *(24) * Refr ig Equip Inventory Report * 6*

(9) * Upward Reportig Status* 7 *

(25) * Refrig Equip Capacity Report * 8 ** 9 **20** 1 ** 2 ** 3 *

(16) * Exit * 4 ** *

Figure 1. Refrigerant Management System Main Menu

G.3 Refrigerant EquipmentInventory (MWQUD)

G.3.1 Refrigerant Equipment Inventory(MIREQUD), Main Menu, PF5

This program (module) is a collection ofpertinent information on all base refrig-eration equipment including, size, refriger-ant capacity, and operational status. Theinformation must be accurate because it isused for various calculations and logicchecks in other parts of this software.

G.3.2 Screen and Field DescriptionsData File: MREQ in MMXXDATA

Control File: MREQ in MMXXCTL

listsThe Air Conditioning/RefrigerationEquipment (Figure 2) directory screenall the equipment loaded in the file byfacility, unit, and model number. AirConditioning/Refrigeration Equipmenttransaction data can be manipulated fromthe Directory screen (Figure 2), or theInput (Detail) screen (Figure 3). PF keysare assigned to data entry functions. SeeAttachment 1 for a list of all assigned PFkeys and their functions. Definitions ofspecific entries on the Air Conditioning/Refrigeration Equipment Input (Detail)screen are as follows.

G-3


A c t i v e A i r C o n d i t i o n i n g / R e f r i g e r a t i o n E q u i p m e n t

I n s t

XLWVXLWVXLWVXLWVXLWVXLWVXLWVXLWVXLWVXLWVXLWVXLWVXLWVXLWVXLWV

F a c i l i t y U n

004620046200474005460054600548005490058000647007270072900741007470084501001

w 01w 02w 01

0912010101

w 0101010101

w 0101

M o d e l

CGABC606AE10FHK23CGABC206AD10BFHK13TTA120A300AACGABC304AC10ABH23CGABC304AE00ARBHCGABC606AE00FHK23CGAA1001EV51AA5A4C361EFRRAWC-101CASCGACD111RNNLV623CPRVWFCGADC25GAGA1ECRVCGADC25GAGA1ECRVCGABC206AE0032KHSCGACC506KANFF603GPVCGACC806RANJJ40G3MCGAA053HF53CC5C4A361EMF

Serial

J84K81833J84B80295FH7193855J83E71400J85C80779J85H82124L84M243954895G45922688J92M84032J92M84029J92M84030J84K81750J87K82731J86K72542L84M24435

Refrig

R-22R-22R-22R-22R-22R-22R-22R-22R-22R-22R-22R-22R-22R-22R-22

Position the cursor and press ENTER to display the entire record.(1)Keys (5)Next (7)Up (8)Find

(10)Queru (13)Help (14)Path (15)Print (16)Retrn(29)Info (30)Histry(31)Rpts

Figure 2. Air Conditioning/Refrigeration EquipmentDirectory Screen (MREQUD)

Base Name:Facility Number:

Description:

Capacity:

Refrigerant Qty:

Manufacturer:Serial #:

Comments:

Air Conditioning/Refrigeration Equipment

TYNDALL AFB MAJCOM: ATCXLWV 462 WCHILLER, HERMl RECIP Unit #: 1

6 0 . TN (TN, HP) Status: I *IN SERVICE*

122. LB Type: R-22

TRANE Model: CGABC606AE10FHK23J84K81833 Date Manufactured: 19841001

(yyyymmdd)CHILLER HAS TWO CIRCUIT EACH HAS 61 LB. R-22

- Opt ional Fields for chi l led water uni ts -AFCESA Condition Assessment: Mult i Site Potential:

(1)Keys (3)Desc [5] Next(10) Quey

(8)Find(13)Help (15)Print (16) Retrn(29)Info (32)Exit

Figure 3. Air Conditioning/Refrigeration EquipmentInput (Detail) Screen (MREQUD)

Note: If an entry is incorrect or has G.3.2.1 Facility Numberchanged since initial input, the entire Identifies where the AC/R equipment isrecord must be deleted (PF12) in the Air located.Conditioning/ Refrigeration Equipmentprogram, and re-entered as a new item. G.3.2.2 Description

G-4


This is a selectable field. To determine various types of equipment that can bethe proper entry, a standardized listing can entered in the description field. To ensurebe accessed by pressing PF14 (Select) standardization across the Air Force, items(Figure 4). This is a valid list of all the cannot be added to this list by the user.

Equipment Description

CHILLER, HERM ABSORP DRINKING FOUNTAINCHILLER, HERM CENTRIF ICE MACHINECHILLER, HERM RECIP REFRIGERATIONCHILLER, HERM SCREW WINDOW AIR CONDITIONERCHILLER, HERM SCROLLCHILLER; OPENED ABSORPCHILLER, OPENED RECIPCHILLER, OPENEND CENTRIFCHILLER, OPENEND SCREWCHILLER, SEMIHERM ABSORPCHILLER, SEMIHERM CENTRIFCHILLER, SEMIHERM RECIPCHILLER, SEMIHERM SCREWDEHUMIDIFIERDIRECT EXPANSIONDIRECT EXPANSION RECIPDIRECT EXPANSION ROTARYDIRECT EXPANSION SCROLL

Place an "H" next to an entry and press ENTER to select.(1)Keys ( 2 ) F i r s t (8)Find

(13)Help (15)Print (16) Retrn(29) Info (32)Exit

Figure 4. Equipment Description Selector File (MREQUD)

G.3.2.3 Unit #If there is more than one unit in a facility,each unit must have a unique number; forexample: 1, 2, 3. Use a local numberingsystem when available, as long as thecombination of the facility number andunit number provide a uniqueidentification.

places. Denote whether the measurementis in tons (TN) or horsepower (HP). Mostentries will be in tons.

G.3.2.5 StatusThis is a selectable field which can beidentified by using PF14 (Select)(Figure 5). The automatic default foradding a piece of equipment is I.

G.3.2.4 Capacity ●

Manufacturer-rated capacity for the unit ●

can normally be found on the nameplate. ●

The screen has space for two decimal ●

I is for In ServiceR is for RepairD is for DecommissionedM is for Mothballed

Status Indicators

D DECOMMISSIONEDI IN SERVICEM MOTHBALLEDR UNDER REPAIR

Figure 5. Status Indicators SelectorFile (MREQUD)

G-5


G.3.2.6 Refrigerant Qty.Manufacturer-rated capacity for the unitshould be found on the equipment’s nameplate. The screen can accommodate up totwo decimal places: "9999.99 .”

Note: When entering numbers to theright of the decimal point, enter anumber in both fields to place thenumbers in the correct position. A

ENTER is pressed. If 0.5_is entered, itwill be translated to 0._ 5”.

G.3.2.7 TypeType of refrigerant is a selected fieldidentified through PF14 (Select)(Figure 6). To input new refrigerant typesyou must access Refrig Bench Stock(PF3) on the Main Menu. Use Add foradding a new bench stock transaction, and

number placed in the tenths space will then Add again to add a new refrigerant.move to the hundredths space when

Refrigerant TypesI n s t Refer Type Location MAJCOMXLWV Ammonia TYNDALL AFB ATCXLWV LiBr TYNDALL AFB ATCXLWV R-11 TYNDALL AFB ATCXLWV R-113 TYNDALL AFB ATCXLWVXLWVXLWVXLWVXLWVXLWVXLWVXLWVXLWV

R-114 TYNDALL AFB ATCR-115 TYNDALL AFB ATCR-12 TYNDALL AFB ATCR-123 TYNDALL AFB ATCR-134A TYNDALL AFB ATCR-22 TYNDALL AFB ATCR-500 TYNDALL AFB ATCR-501 TYNDALL AFB ATCR-502 TYNDALL AFB ATC

Place an "X" nex t to an ent ry and press ENTER to se lec t .

G.3.2.8

Figure 6.

Manufacturer, Model,Date Manufactured

Type Selector File - Locations andRefrigerant Types (MREQUD)

and Note: Do not make up a serial number,since this may lead to more than one

Figure 7. Data from the unit having the same number.Refer tonameplate or other reliable source.

G.3.2.9 Serial #This number must be unique for eachpiece of equipment on the base to ensurethe program can uniquely identify eachunit. If this number is not available fromnameplate data, a random number must begenerated, while in Add or Modify mode,by selecting PF17 (Serial) from the Input(Detail) screen.

G.3.2.10 CommentsUsed for recording any refrigerantmanagement comments.

G.3.2.11 AFCESA ConditionAssessment

The condition is one of four numericcodes. It is an overall condition andshould reflect the status of the unit at thetime of evaluation. It is the evaluator’s

G-6


- Optional Fields for chilled water units -AFCESA Condition Assessment: Mult i Site Potential:

(1)Keys (3)Desc(10)Query (13)Help (14)Select (15)Print (16)Retrn

(17)Serial (29)Info (32)Exit

Figure 7.

impression and should not

Air Conditioning/Refrigeration Equipment Input(Detail) Screen (MREQUD) Data Entry ModeShowing PF17, Serial, Option

require any Lists every unit by facility and unitsignificant work effort to determine. Noengineering studies should be needed todetermine this code.

G.3.2.12 Multi-Site PotentialThis is for chilled water units only. Thedata field identifies the possibility that thechilled water from this unit, along withother units, could be provided by a newcentrally chilled water plant. The numbercan go up to 9999 (no decimals).

G.3.3 Standard ReportsThe software generates two standardreports from data input through the AirConditioning/ Refrigeration Equipmentscreen. They are:

G.3.3.1 Main Menu, PF 24 (Figure 8):Refrig Equip Inventory Report- By Facility

number. This report provides generalinformation on the entire refrigerationsystem at the base.

G.3.3.2 Main Menu, PF 25 (Figure 9):Refrig Equip Capacity Report -By Refer Type

Lists, by type of refrigerant, all units,refrigerant charges for each unit, and totalinstalled charge for all units. This reportprovides general information on the entirerefrigeration system.

G.3.4 Special Features

G.3.4.1 Model and Serial NumbersThe manufacturer’s model and serialnumbers may be difficult, or impossible todetermine. When necessary, the refrig-erant manager should generate a new serialnumber to identify the equipment. A newserial number can be generated using

G-7


REPORT DATE 94/06/22 Refrig Equip Inventory Report - By Facility PAGE 1

VERSION 4.01.000.000 93/05/31 (MREQFAC IN MMXXRPT)

FACILITY DESCRIPTI0N UNIT STATUS CAPACITY UM TYPE UOLUME- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

XLWV 115XLWV 115XLWV 147XLWV 147XLWV 147XLWV 147XLWV 147XLWV 150XLWV 302XLWV 302XLWV 313XLWV 313XLWV 2521

CHILLER, SEMIHERM CENTRIF 1 I 259.09 TNCHILLER, SEMIHERM CENTRIF 2 I 259.08 TNCHILLER, SEMIHERM CENTRIF D 120.00 TNCHILLER; SEMIHERM CENTRIF I 120.00 TNCHILLER, SEMIHERM CENTRIF I 120.00 TNCHILLER, SEMIHERM CENTRIF 2 I 120.00 TNCHILLER, SEMIHERM CENTRIF I 120.00 TNCHILLER, SEMIHERM CENTRIF I 150.00 TNDIRECT EXPANSION RECIP 1 I 40.00 TNDIRECT EXPANSION RECIP I 40,00 TNCHILLER, SEMIHERM CENTRIF 1 I 210.00 TNCHILLER, SEMIHERM CENTRIF 2 I 2110.00 TNREFRIGERATION 3 I 5.00 TN

CFC-11CFC-11CFC-12CFC-12CFC-11CFC-11CFC-11CFC-113CFC-12CFC-12CFC-12CFC-12CFC-502

640.05640.05340.00340.00340.00340.00340.00500.00250.00250.00900.00900.0010.00

Figure 8. Refrig Equip Inventory Report - By Facility (MREQFAC)

REPORT DATE 94/06/22 Equipment Capacity Inventory - By Refer Type PAGE 1

VERSION 4.02.000.000 93/12/01 (MREQCAP IN MMXXRPT)

REFER TYPE CAPACITY UM DESCRIPTION UNIT FACILITY STATUS- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

CFC-11 259.08 TN CHILLER, SEMIHERM CENTRIF 1 XLWV 115 ICFC-11 259,08 TN CHILLER, SEMIHERM CENIRIF 2 XLWV 115 ICFC-11 120.08 TN CHILLER, SEMIHERM CENTRIF XLWV 147 ICFC-11 120.00 TN CHILLER, SEMIHERM CENTRIF 2 XLWV 147 ICFC-11 129.00 TN CHILLER, SEMIHERM CENTRIF XLWV 147 I

SUBT0TAL: 878,08

CFC-113 150.00 TN CHILLER, SEMIHERM CENTRIF XLWV 150 ICFC-113 150.80 TN CHILLER, SEMIHERM CENTRIF XLWV 6300 I

SUBTOTAL: 300.00

Figure 9. Refrig Equip Capacity Report - By Refer Type (MREQCAP)

PF17 (Serial) from the Refrigerant no longer be monitored. This must beEquipment Serviced Input (Detail) screen. accomplished through the RefrigerationSee Field Description under Serial #. Equipment Serviced, Main Menu, PF1 fileAlso, the equipment should be marked by changing the Status field to a D forwith the new number for future reference decommissioned.using stencils or engraved plates.

G.3.4.3 Reactivate (Delete/Move) aG.3.4.2 Move Records to History File History FileEquipment items may be moved to the To reactivate a history record, use thehistory file if refrigerant consumption will PF28 (Move) under the Air Conditioning/

G-8


Refrigeration Equipment. After thehistory file is reactivated the record statusmust be modified from D, for decommis-sioned, to one of the following statusindicators. Modify the Status to:● R for Under Repair;● I for In Service; or● M for Mothballed.The reactivated file will also show up onthe list under the Refrig EquipmentInventory submodule.

G.3.4.4 Changing Information onExisting Entry

After using PF5 to get to the Air Condi-tioning/Refrigeration Equipment screen,position the cursor on the entry to modify,and press Modify (PF9). This will accessthe original entry screen. Make themodifications; press ENTER to save themodifications.

Note: Manufacturer, Model, and Serial# cannot be modified. To change theseentries the entire record must be deletedand a new record added with the neces-

sary changes. The record can be deletedfrom the Air Conditioning/ RefrigerationEquipment screen or the screen thatshows the current information on thatspecific piece of equipment.

G.4 Refrigerant EquipmentServiced (MRESUD)

G.4.1 Refrig Equipment Services(MRESUD), Menu, PF1

This submodule tracks the amount ofrefrigerant used to service each piece ofequipment in the Refrig EquipmentInventory. It contains the upward report-ing capabilities for all the submodules inthe Refrigeration Management program.

G.4.2 Screen and Field DescriptionsData File: MRES in MMXXDATAControl File: MRES in MMXXCTL

G.4.2.1 The first screen accessed withPF1 is Refrigerant Equipment Serviceddirectory screen (Figure 10). Thedirectory screen lists all the service

Active Refrigerant Equipment Serviced

l n s t F a c i l i t y U n i t M a n u f a c t u r e N a m e M o d e l N u m b e r D a t e

XLWU 00462 W 01 T R A N E CGABC606AE10FHK23 19940611XLWU 00462 W 01 T R A N E CGABC6069AE10FHK23 19940627XLWU 00546 09 T R A N E CGABC304AC10BH23 19940207XLWU 00548 01 TRANE CGABC606AE00FHK23 19940325XLWU 01046 01 T R A N E CGACC601KBNGG623G 19940322XLWU 01060 01 T R A N E CGAA1001ED51AA5C361EFRXLWU 01140

1994041101 T R A N E CGACC306KBNDD303FGPU

XLWU 0180119940217

01 TRANE CGAA0804RJ51CC4C4C361JRA 19930927XLWU 01801 01 TRANE CGAA0804RJ51CC4C4C361JRA 19930927

P o s i t i o n t h e c u r s o r a n d p r e s s E N T E R t o r e c o r d .(1)Keys(9)Modify(10)Query (11)Add

(8)Find(12)Delete(13)Help (14)Path (15)Print (16)Retrn

(27) Upward(28)Archu (29)Info (30)Histry(31)Rpts

Figure 10. Refrigeration Equipment ServicedDirectory Screen (MRESUD)

G - 9


transactions that have occurred over thelast two years. Two years is an importantlength of time because EPA requiresservice records be maintained for threeyears. With two years of records stored inthe Refrigerant Management program andone year in taped storage, EPA require-ments are met.

G.4.2.1.1 If more information is neededon an individual transaction, move the

ENTER. The Air Conditioning/ Refrig-eration Equipment Serviced Input (Detail)screen (Figure 11) will be displayed.From this screen you can Modify (PF9)the remarks and the technician’s name;Add (PF11) a totally new service record;and, access the Air Conditioning/Refrig-eration Equipment Inventory using PF17(Equip).

G.4.2.1.2 To view History records,cursor to that transaction and press press PF30 (History).

Air Conditioning/Refrigerant Equipment Serviced

Instl /Bldg: XLWU / 546 Manufacture: TRANETYNDALL AFB Model Number: CGABC304AC10ABH23

Unit Number: 9 Serial Number: J83E71400

Refrig Type: R-22 Oil Change: N (Y/N)Trans Type: I (I=Install in Machine) Filter Change: N (Y/N)

(R=Remove from Machine) Oil Qty Added:Refrig Cond: U (U=Usable, N=Not Usable) Hour Meter:Trans Qty: 64 . lbs Equip Status: I

Remarks:

Technician: ROSARIO, ROBERTO Trans Date: 19940207Signature:

(1)Keys (2) F i rs t (3)Desc (4)Prev (5)Next (8)Find(9)Modify(10)Query (11)Add (13)Help (15)Print (16)Retrn

(17)Equip (29)Info (32)Exit

Figure 11. Air Conditioning/Refrigeration EquipmentServiced Detail Screen (MRESUD)

G.4.2.2 Most transactions from the Conditioning/Refrigeration EquipmentRefrigerant Equipment Serviced screenwill be accomplished through Add (PF11).The Add function can be accessed fromeither the directory or the Input (Detail)screen. In pressing Add from the directoryscreen, the Select the Equipment Item tobe Serviced screen (Figure 12) will bedisplayed. To pick the piece of equipmentfor a service transaction, press PF17(Equip). The user will be taken to the Air

Inventory. A Find (PF8) key is availableto aid the search. After finding the rightpiece of equipment, press ENTER todisplay the specific piece of equipmentscreen.

Note: After accessing the RefrigerationEquipment Inventory, press PF16 (Retrn)to return to the Air Conditioning/Refrigeration Equipment Serviced screen.

G-10


Select the Equipment Item to be ServicedInstl Facility Unit Manufacture Model

XLWU 00462 W 01 TRANE CGABC606AE10FHK23XLWU 00462 W 02 TRANE CGABC206AD1OBFHK13XLWU 00474 W 01 TRANE TTA120A300AAXLWU 00546 09 TRANE CGABC304AC109BH23XLWU 00546 12 TRANE CGABC304AE00ABHXLWU 00548 01 TRANE CGABC606AE00FHK23XLWU 00549 01 TRANE CGAA1001EU51AA5A4C361EFRXLWU 00588 01 TRANE RAWC-101CASXLWU 00647 W 01 TRANE CGACD111ANNLU623CPRVWF

Figure 12. Select the Equipment Item to be Serviced—Screen (MRESUD)

The next screen is the Air Condition- Model Number, Serial Number, anding/Refrigeration Equipment Serviced Refrig Type filled in. The softwareInput (Detail) screen (Figure 13). Inform- retrieves this information from the Refrigation on service performed on a specific Equipment Inventory submodule. The re-piece of equipment can be added on this maining screen fields to be filled are listedscreen. The screen should already have below.Instl/Bldg, Manufacturer, Unit Number,

G.4.2.2.1Type in Y

G.4.2.2.2Type in Y

Air Conditioning/Refrigeration Equipment Serviced

Instl /Bldg: XLWU / 546 Manufacture: TRANETYNDALL AFB Model Number: CGABC304AC10ABH23

Unit Number: 9 Serial Number: J83E71400

Refrig Type: R-22 O i 1 Change: N (Y/N)Trans Type: I (I= Intstall in Machine) Filter Change: N (Y/N)

(R=Remove from Machine) Oil Qty Added:Refrig Cond: U (U=Usable, N=Not Usable) Hour Meter:Trans Qty: 64 . lbs Equip Status: I

Remarks:

Technician: ROSARIO, ROBERTO Trans Date: 1994e2e7Signature:

(1)Keys (2) First (3)Desc (4)Prev(9)Modify(10)Query (11)Add

(5)Next (8)Find(13)Help (15) Print (16) Retrn

(17) Equip (29)Info (32)Exit

Figure 13. Air Conditioning/Refrigeration EquipmentServiced Input (Detail) Screen (MRESUD)

Oil Change G.4.2.2.3 Oil Qty Addedfor yes; N for no. Type in number (up to 999; no decimals)

of quarts of oil used during the oil change,Filter Change or amount added during this servicing

for yes; N for no. without an oil change.

G-11


G.4.2.2.4 Hour MeterIf the unit has an hour meter, record thetime shown. This number goes up to999,999 (no decimals).

G.4.2.2.5 Trans TypeType in an I representing the technicianinstalling refrigerant to the unit. Type inan R representing the technician removingrefrigerant from the unit.

G.4.2.2.6 Refrig CondType in U for usable; N for not usable.

G.4.2.2.7 Trans QtyType in the number of pounds of refriger-ant that was either installed or removedduring this servicing. The number can beup to 99,999.99. The program will notallow installing or removing more refrig-erant in the unit at one servicing than theunit can hold. If it holds 300 pounds perthe Refrig Equipment Inventory submod-ule, then up to 300 pounds can be installedor removed. It is very important to havethe correct quantity for every servicetransaction. The report which computesthe unit’s refrigerant consumption rate usesthese quantities for the final calculation.

Note: When entering numbers to theright of the decimal point, enter anumber in both fields to place thenumbers in the correct position. Anumber placed in the tenths space willmove to the hundredths space whenENTER is pressed. If 0.5_ is entered, itwill be translated to 0._5.

G.4.2.2.8 Equip StatusThe computer will display a status on thescreen. It will be the status from the lastservice transaction, and will be either I forIn Service, R for Under Repair, or M forMothballed. It will not show D forDecommissioned. Once a unit is decom-missioned, it is moved to the History fileautomatically, and cannot have a servicetransaction placed against it. ParagraphG. 3.4.1 on Refrig Equipment Inventoryexplains how to make a unit active once ithas been decommissioned.

G.4.2.2.9 RemarksA suggested use for this area is to write inwhat was done during the servicing.

G.4.2.2.10 TechnicianThis is a selectable field. Use PF14 toshow the list of technicians who work atthe base. To choose a name, place an Xnext to the name, and press ENTER.

Note: Modifications can be made to thisselector file. Names can be added to thelist using PF11, or deleted from the listusing PF12.

G.4.2.2.11 Trans DateThis is the date the transaction takes place.You can input service transactions whichoccurred on dates prior to the current date.It is very important to have the correctdate for every service transaction. Thereport which computes the unit’s refriger-ant consumption rate uses these dates forthe final calculation.

G-12


G.4.2.2.12 Signature G.4.3 Standard ReportsThis place is reserved for signature of the This module generates two standardtechnician who accomplished the work. reports.Print a hard copy of this screen and give itto the technician to fill out after he/she G.4.3.1does the work. The signature indicates thework was completed and signed off, andmakes inputting the data to the computereasier. Use of this procedure is a local This report lists in chronological order alldecision that may be started by the base as the issues and receipts with amounts andpart of an overall Refrigerant Management types of refrigerants identified along withprogram. the responsible technician.

They are:

Main Menu, PF18 (Figure 14):Refrig Service Log Report(Also Known as the RefrigerantIssue/Receive Log - By Date)

REPORT DATE 94/06/22 Refrigerant Issue/Receive LOg - By Date PAGE 1

VERSION 4,01,000,000 93/02/01 (MRESLOG IN MMXRPT

DATE Y/M/D (I)SSUE AM0UNT RFR TYPE (U)SABLE/ TO/FROM----------------- (R)ECEVE ------ ---------- (N)OT USABLE ----------------------------------

1993/04/29 I 10.00 CFC-11 U PAT DAUGHERTY1993/05/055 I 10.00 CFC-11 U RICH BAUMAN NC1993/05/05 I 30.00 CFC-11 U PAT DAUGHERTY1993/10/29 I 30.00 CFC-11 U PAT DAUGHERTY1993/11/05 I 15.00 CFC-11 U PAT DAUGHERTY1993/11/05 I 40.00 CFC-11 U1994/01/01 I

RICH BRAUMAN NC10.00 CFC-11 U RICH BRAUMAN NC

1994/01/29 I 10.00 CFC-11 U PAT DAUGHERTY1994/02/07 I 64.00 R-22 U ROSARIO, ROBERTO1994/02/17 I 44.00 R-22 U ROSARIO, ROBERTO1994/03/11 I 10.00 CFC-12 U PAT DAUGHERTY1994/04/11 I 18.00 CFC-12 U PAT DAUGHERTY1994/04/1 8 R 00 CFC-12 U PAT DAUGHERTY

Figure 14. Refrigerant Issue/Receive Log (MRESLOG)

G.4.3.2 Main Menu, PF19 (Figure 15):Refrig Consumption Report ●

(Also Known as the RefrigerantConsumption Rates - By Fac-ility, Equipment, and Service ●

D a t e ●

This report provides the informationnecessary to comply with the EPA leak ●

rate restrictions. IT IS THE MOSTIMPORTANT REPORT IN THISSOFTWARE PROGRAM.● The % used column is the leak rate for

the listed unit based on the most recent

service data.The information to determine this leakrate comes from the data entered in theRefrig Equipment Serviced file.The % used is an annual rate.If the rate is over 99%, the notation is99+.The % used is the percent of totalcharge the unit will leak in the nexttwelve months based on the amountleaked over the period between the lasttwo servicing.

G-13


Refrigerant Consumption Rates - by Facility, Equipment, & Suc Date

Version 4.02.000.000 93/11/01 MRESFAC MMXXOBJ

Fac i l i t y Unit Description Suc Date Charge Type x used- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -XLWU 313 1 CHILLER, SEMIHERM CENTRIF 940611 35.00 CFC-12 23XLWU 313 1 CHILLER, SEMIHERM CENTRIF 940811 22.00 CFC-12 14XLWU 313 1 CHILLER, SEMIHERM CENTRIF 941013 10.00 CFC-12 6XLWU 6300 CHILLER, SEMIHERM CENTRIF 940512 400.00 CFC-113 99 +XLWU 115 1 CHILLER, SEMIHERM CENTRIF 931105 15.00 CFC-11 9XLWU 115 1 CHILLER, SEMIHERM CENTRIF 940505 20.00 CFC-11 6XLWU 115 1 CHILLER, SEMIHERM CENTRIF 940509 60.00 CFC-11 99 +XLWU 115 1 CHILLER, SEMIHERM CENTRIF 940513 1.00 CFC-11 29XLWU 115 1 CHILLER, SEMIHERM CENTRIF 940621 639.05 CFC-11 99+XLWU 115 1 CHILLER, SEMIHERM CENTRIF 940621 38.05 CFC-11 99 +XLWU 115 2 CHILLER, SEMIHERM CENTRIF 940507 50.00 CFC-11 8XLWU 147 2 CHILLER, SEMIHERM CENTRIF 940515 340.00 CFC-11 99

Figure 15. Refrigerant Consumption Rates - by Facility,Equipment, & Svc Date (MRESFAC)

The specific calculation used to deter-mine this rate can be found in theRefrigerant Manager’s Handbook inChapter 2. If the unit is used forrefrigeration and the rate is higher than35%, or used for something other thanrefrigeration and the rate is higher than15%, EPA regulations are violated. Anyunits exceeding or violating EPA regu-lations must be repaired within 30 days,or a retirement plan developed within 30days which will be completed withintwelve months.

G.5

G.5.1

REFRIGERANT BENCHSTOCK ADJUSTMENT(MRTRUD)

Refrigerant Bench StockAdjustment (MRTRUD) MainMenu (PF3)

This module is a listing of the refrigerantissued or received by the RefrigerantManager (RM). When the RM receivesrefrigerant from a technician or othersource for bench stock, a transaction must

be entered to increase the recorded stocklevel of the refrigerant received. Like-wise, when refrigerant is issued to atechnician or to someone outside CE, atransaction must be entered to decrease therecorded stock level.

Note: The Refrig Equipment Servicedsubmodule does not update the RefrigBench Stock submodule.

G.5.2 Screen and Field DescriptionsData File: MRTR in MMXXDATAControl File: MRTR in MMXXCTL

G.5.2.1 The first screen of the Refriger-ant Bench Stock Adjustment program isRefrigerant Turn-In and Receiving Filedirectory screen (Figure 16). The screenall transactions accomplished through theAdd key (PF11). If a mistake is made en-tering a new transaction, it must be deletedusing PF12. A specific transaction can becalled up from this screen by positioningthe cursor next to the transaction toreview, and pressing ENTER.

G-14


Active Refrigerant Turn-In and Receiving File

Inst Refrigerant D a t e Iran Cond Tran Qty MAJCOM

XLWU R-11 19940311 R U 1890.00 ATCXLWU R-22 19930924 R U 100.00 AETCXLWU R-22 19940214 R U 100.00 ATCXLWU R-22 19940308 R U 125.00 ATCXLWU R-22 19940323 R U 125.00 ATCXLWU R-22 19940325 R U 125.00 ATCXLWU R-22 19940412 R U 125.00 ATCXLWU R-22 19940412 R U 125.00 ATCXLWU R-22 19940412 R U 125.00 ATCXLWU R-582 19940311 R U 290.08 ATC

Position the cursor and press ENTER to display the entire record.(1)Keys (8)Find

(1O)Query (11)Add (12)Delete(13)Help (14)Path (15)Print (16)Retrn(28)Archu (29)Info (30)Histry(31)Rpts

Figure 16. Refrigerant Turn-In and Receiving FileScreen (MRTRUD)Directory

G.5.2.2 Most transactions under theRefrigerant Turn-In and Receiving Filedirectory screen will be accomplishedthrough the Add (PF11). When in Addmode, the Refrigerant Stock AdjustmentInput (Detail) screen (Figure 17) is

accessed. This screen is used every time arefrigerant transaction occurs. With theseinputs the computer keeps a running totalof the refrigerant in the BCE’s inventory.The running total is not updated by anyother submodules in the RIMS software.

Refrigerant Stock Adjustment

Installation Code: TYNDALL A Major Command: ATC

Refrigerant Type : R-11 YYMMDDTransact ion QtY : 1890 . 00 Lbs Transact ion Date: 19948311

Transact ion Type : R (1 = Issue to CE Technican)(2 = Received from outside of CE)(3 = Received from CE Technican )(4 = Issued to Outside CE)

Refrigerant Cond : U (U = Usable, N = Unusable)

Usable Inventory Qty: 1898 . LbsUnusable Inventory Qty: Lbs

NameI s s u e d t o Technician:Received From Outside CE:Received From Technician:I s s u e d t o Outside CE:

(1)Keys (3)Desc (5)Next (8)Find(10)Query (11)Add (13)Help (15)Print (16)Retrn

(29)Info (32)Exit

Figure 17. Refrigerant Stock Adjustment Detail ScreenDirectory Screen (MRTRUD)

G-15


Each issue and receipt must be accom-plished as a separate transaction underAdd. The four input definitions for theRefrigerant Stock Adjustment screen are asfollows:1 = Issue to CE TechnicianThis tracks the refrigerant signed out toeach technician. It could be a quantity ofrefrigerant for a specific unit or for manyunits. Each issue must be recorded with aseparate transaction.2 = Received From Outside of CEAny refrigerant that comes to the inven-tory from other than a CE technician.This could be from Base Supply, Contract-ing, GOCESS, GOCESS, or interbasetransfer. Each receipt must be recordedwith a separate transaction.3 = Received From a CE TechnicianThis tracks the refrigerant returned toinventory by each technician. The turn-incould be due to base procedures requiringdaily turn-in of unused refrigerant, orrefrigerant recovered from a mothballed ordecommissioned machine for storage orreclaiming. Each receipt must be recordedwith a separate transaction.4 = Issued to Outside CEThis will occur when refrigerant is sent toanother base, or to a contractor forreclaiming. Each issue must be recordedwith a separate transaction.

Note: Before an Add can occur, allrefrigerant types used by the base mustbe identified.

This is accomplished by selecting PF14 onthe Refrigerant Stock Adjustment screen,at the Refrigerant Type field. TheLocations and Refrigerant Types screen(Figure 6) is accessed. Again, select PF1lto Add the refrigerants used by the base.

G.5.2.3 Refrigerant Cond is eitherUsable (U) or Unusable (N). The pro-gram keeps a separate running total onboth.

G.5.2.4 Usable Inventory Qty is a cur-rent total of good refrigerant in inventory.It is composed of all transactions for aspecific refrigerant up to but not includingthe current transaction.

G.5.2.5 Unusable Inventory Qty is acurrent total of contaminated refrigerant ininventory. It is composed of all trans-actions for a specific refrigerant up to butnot including the current transaction.

G.5.2.6 Issued to Technician andReceived From Technician are selectablefields through PF14 (Select). Using PF14will give you a list of all technicians thatthe RM can issue refrigerant to or receiverefrigerant from.

G.5.3 Standard ReportsThis submodule generates two standardreports from data input through theRefrigerant Stock Adjustment screen. -

They are:

G.5.3.1 Main Menu (PF22) (Figure 18)- Refrig Bench Stock Report

This Bench Stock Transaction Log - ByDate report provides a listing of alltransactions in ascending chronologicalorder, the earliest transaction first.

G.5.3.2 Main Menu (PF23) (Figure 19)- Refrig Quantities Report

This Refrigerant Inventory report gives thecurrent total of each refrigerant used onbase and managed by the software.

G-16

Appendix G — Work Information Management System (WIMS)

REPORT DATE 94/06/22

AFR TYPE- - - - - - - - - -

CFC-11CFC-11CFC-113CFC-12CFC-500CFC-582CFC-11CFC-113CFC-113CFC-500CFC-11CFC-11CFC-11

AMOUNT- - - - - -

1001000010000100001000010000

64010000

100800

555050

T/R CONO- - - - - - -

1 U2 U2 U2 U2 U2 U3 U4 U33 U1 U1 U1 U

Bench Stock Transaction Log - By Date P a g e 1From: All Thru 940622VERSION 4.01.000.000 93/02/01 (MRTRLOG IN MMXXRPT)

DATE=Y/M/D AGENCY- - - - - - - - - - - - - - -

1993/04/291994/04/281994/04/281994/04/281994/04/281994/04/281994/04/291994/04/291994/04/291994/04/091994/05/111994/05/111994/05/11

PAT DOUGHERTYINITIAL INVENTORYINITIAL INVENTORYINITIAL INVENTORYINITIAL INVENTORYINITIAL INVENTORYPAT DOUGHERTYRECLYCLERPAT DOUGHERTYRICH BAUMAN NCPAT DOUGHERTYPAT DOUGHERTYPAT DOUGHERTY

Figure 18. Bench Stock Transaction Log (MRTRLOG)

REPORT DATE 94/06/22 Refrigerant Inventory PAGE 1

VERSION 4.02.000.000 93/12/01 (MRQTINV IN MMXXRPT)

MAJCOM BASE NAME RFR TYPE GOOD QTY BAD QTY- - - - - - - - - - - - - - - - - - - -- - - - - - - - - - - - - - - - - - - - - - - - - - -

AETC TYNDALL CFC-11 10995.50 0

TOTAL QTY FOR REFRIGERANT TYPE: 10995.50 0

AETC TYNDALL CFC-113 90.00 0

TOTAL QTY FOR REFRIGERANT TYPE: 90.00 0

AETC TYNDALL CFC-12 10000.00 0USAFE AVIANO CFC-12 0 0

Figure 19. Refrigerant Inventory (MRQTIN)

G.5.4 Special Feature: Tracking for PF11 (Add) to add a new installationOther Bases (Inst), refrigerant type (Refer Type), base

For organizations that will be trackingrefrigerant usage for other bases/locations(Air National Guard and USAFE), theother base’s installation code, base name,and MAJCOM should be entered. UsePF14 (Select) on the Refrigerant StockAdjustment Screen (Figure 17) to accessthe Locations and Refrigerant TypesScreen (Figure 6). From this screen, use

name, and MAJCOM. This file is usedby all the Refrigerant Management sub-modules to ascertain the necessaryrefrigerant for individual bases. Whenadding records to track usage for anotherbase, care must be taken to ensure thatrefrigerant from their bench stock is keptseparate.

G-17


Note: Always ensure that the Management Upward Reporting Resultsinstallation code is entered correctly. screen (Figure 20) displays the dates files

G. 6

G.6.1

sent from different bases and MAJCOMsUpward Reported Data Logs to higher headquarters. This helps the

(MRURUD) MAJCOMs and AFCESA know how cur-rent information is in their data files.

Upward Reported Data Logs(MRURUD) - Main Menu (PF9) G.6.2 Management Benefits

This submodule is for MAJCOM and Analysis and interpretation of the WIMSAFCESA use. The Refrigerant refrigerant reports enable the RM to:

Refrigerant Management Upward Reporting Results

M A J C O M B A S E N A M E M e r g e D a t e / T i m e A r r i v e

There are no records in the file.

(15)Print (16)Retrn(29)Info (31)Rpts

●

●

●

●

Figure 20. Upward Reporting Data Log

Establish equipment repair prioritiesbased on consumption rates. This ●

allows the concentration of limited laborresources to where they can do the mostgood.

●

Compare projected refrigerantinventories to consumption rates toensure continued mission support.

●

Use the consumption records to helpprioritize conversion or replacement of

●

equipment.Compare different equipment repair andconvert/replace strategies with theireffect on estimated refrigerant depletion

G-18

rates.Identify low-use equipment for possiblemothballing for extended periods oftime to eliminate leakage.Estimate the labor requirements neededto maintain equipment at minimumrefrigerant consumption levels.Develop metrics to measure the successof conservation efforts.Provide a list of buildings which, due totheir proximity and system types, arepotential candidates for replacementwith small chilled water plants.

Appendix G — Work Information Management System (WIMS)

G. 8 Definition of Terms

In-Service: When a unit is operational.

Under Repair: When a unit is tempor-arily down for repair.

Mothballed: When a unit is taken outof service for the winter or non-airconditioning season, including the removalof its refrigerant, and will be rechargedand put back in service at the start of thenext cooling season.

Decommissioned: When a unit is perman-ently removed from service.

Usable: Describes the condition of therefrigerant. Usable refrigerant can beplaced in a unit without recovery orreclamation.

Unusable: Describes the condition of therefrigerant. Unusable refrigerant cannotbe placed in a unit without first beingrecovered or reclaimed.

AFCESA Condition AssessmentDefinitions:4 - An intolerable condition, wherecomponents have failed or failure isimminent.3 - A serious condition, but conditions are

tolerable. Failure is probable but work-arounds can be established.2 - All equipment is operational. Routinepreventive maintenance is required topreserve reliability.1 - System is fully operational and nowork in the infrastructure program isrequired.

Calculation for Multi-Site Potential:

First, use the procedure for determiningpossible locations for central chilled waterplants detailed in the RefrigerantManagement Handbook, Appendix H.

Second, for each possible locationdetermine the approximate supply linelength (round off to the nearest hundredfeet: 100, 200) needed to connect allunits. Assign that same number (distance)to each unit in the group. For example, ifthere are five units that could be served byone plant, and it would take approximately1100 feet of supply line to connect allunits, assign the number 1100 to the datafield for all five units. Follow thisprocedure for each possible location. Iftwo plants require the same line distance,round up or down to the nearest 100 (1000or 1200) so each group can be identifiedseparately.

Note: Provide only approximatedistances between buildings.

G-19 (G-20 Blank)

PF Keys

Key

1

5

7

8

9

10

11

12

13

14

15

16

17

17

27

28

28

29

30

31

32

Function

Keys

Next

u p

Find

Modify

Query

Add

Delete

Help

Path

Print

Retrn

Serial

Equip

Upward

Move

Archv

INFO

Histry/Active

Rpts

Exit

Description

Displays the PF Key functions

Displays the next full screen of records

Moves the display up one record

Allows

Allows

Allows

Allows

Allows

the search for a specific record

modification of a selected record

user-designed inquiries

addition of new records to the file

deletion of selected record(s)

Displays documentation on this application

Resorts the data by an alternate path

Prints the screen being displayed

Used to return to the previous screen or exit out ofprogram

Used to select unique equipment serial numbers from theAir Conditioning/Refrigeration Equipment program

Used to access the Air Conditioning/RefrigerationEquipment inventory from the Refrigeration EquipmentServiced program

Upward reports Refrigeration System data from theRefrigeration Equipment Serviced program

Used to move records to history, or from history to active

Archives records to history after two years (RefrigerationEquipment Serviced program)

Allows access to all the INFO documents

Switch between Active and History Files

Displays Reports

Used to Exit the program

Appendix G - Attachment 1

Appendix H — AC/R Equimnent Survey Guide and Equipment Data Collection Survey Forms

Appendix H — AC/R Equipment Survey Guideand

Equipment Data Collection Survey Forms

ABSTRACT: This appendix will assist the base Refrigerant Manager (RM) conducting a surveyof air conditioning and refrigeration (AC/R) equipment. The purpose of the survey is to assessand record the condition of equipment that uses chlorofluorocarbons (CFCs) or hydrochloro-fluorocarbons (HCFCs) as a refrigerant. This information will be used to assemble a RefrigerantManagement Plan (RMP).

H.1 Introduction

This appendix provides instructions andbackground information for performing asurvey of AC/R equipment using UtilitiesData Sheets, the AC/R Equipment SurveyForm for Water Chillers, and the AC/REquipment Survey Form for Air Condi-tioning & Refrigeration Equipment. Blankcopies of these forms are included asattachments to this appendix. They can bephotocopied and used to complete thesurvey.

H.11 Required ItemsThe following items are required to per-form the survey:● AC/R equipment survey forms,● a three-ring binder for carrying survey

forms, and● a portable refrigerant leak detector,

(see Appendix D, Refigerant LeakDetection Methods and Equipment.

H.1.2 Recommended ItemsIn addition to the required items, the fol-lowing items are recommended to performthe survey:

● extra battery power for the portableleak detector,

● extra sensors and filters for leak detec-tors,

● a flashlight, and● hearing protection (ear plugs).

H.2 Completing the UtilitiesData Sheet

Utility bills for electric and natural gasservices provide a record of the consump-tion and cost of these utilities. This infor-mation will be useful in evaluating thevarious electric- and gas-powered retrofitor replacement alternatives discussed inAppendices M, Evaluating Water Chillersfor Replacement or Retrofit Potential, N,Chiller Selection Guide, O, Assessing thePotential of Central Chilled Water Plants,P, Heat Recovery Alternatives for Refriger-rant Chillers, and Q, Assessing the Poten-tial of Thermal Energy Storage. The Utili-ties Data Sheet (Attachment 1) organizesthis information into a useful form. Aseparate sheet is needed for each separateelectric or gas service billed to the base.Complete the Utilities Data Sheet using

H-1

Appendix H — AC/R Equipment Survey Guide and Equipment Data Collection Survey Forms

utility bills for the preceding 12 months.See the base civil engineer’s (BCE’s)Resource Management group for thisinformation.

H.3 Organizing the Survey

Make one copy of the appropriate blanksurvey form (either for water chillers orAC/R equipment) for each piece of equip-ment using CFCs or HCFCs as a refriger-ant.

H.3.1 Data RetrievalAccess the Work Information ManagementSystem (WIMS) Refrigerant ManagementSoftware for data on each piece of equip-ment that uses CFCs or HCFCs. Recordthe facility number, unit number, datemanufactured, and refrigerant quantity andtype on Part I of the survey form.

H.3.2 Sort FormsSort the survey forms by refrigerant type,refrigerant quantity, age, and location(optional). This is recommended so unitsare surveyed in order of importance. Sortin the following order:●

●

●

●

●

separate the forms for CFC- andHCFC-units into piles;sort each pile in descending order byrefrigerant quantity;retaining this order, sort each pile byage, placing older units on top ofyounger units of equal refrigerantquantity;place the CFC pile on top of theHCFC pile, andif more than one person is conductingthe survey or to reduce travel time,sort survey forms by location.

H-2

H.3.3 Map LocationsOn an up-to-date, to-scale Base Site Planshowing the facilities, mark the approxi-mate location of each unit and its unitnumber. If locations can not be determinedprior to the survey, they must be deter-mined during the survey.

H.3.4 Mapping Water ChillersUsing compass or circle template, draw acircle around each chiller (or chiller plant)of radius equal to its capacity in tons. Thiscircle is the “capacity radius” of the chill-er. For example, a 1,000-foot radius circlewould be drawn around a 1,000-ton chiller(or chiller plant); a 200-foot radius circlewould be drawn around a 200-ton chiller(or chiller plant). Overlapping circlesindicate a potential to combine these chill-ers into a central system. Further assess-ment of this potential will be made duringthe survey.

H.4 Performing the Survey

The instructions and additional informationin this section relate directly to the AC/REquipment Survey Form for water chillers(Attachment 2); however, they pertain tothe Survey Form for air conditioning andrefrigeration equipment (Attachment 3) aswell. Both Forms are divided into fiveparts:Part I. General DataPart II. Service DataPart III. Assessment of Mechanical

RoomPart IV. Assessment of EquipmentPart V. Action Items


H.4.1 Complete Part IPart I is for recording general data thatmay be available at the site of the equip-ment. This information is then used toverify and update the WIMS RefrigerantManagement Software.

H.4.1.1 Line 1 - One of the end-productsof this survey is an up-to-date AC/Requipment database. This is accomplishedby completing Part I by inspection. Fol-lowing the survey, any additions andcorrections will be input to the WIMSRefrigerant Management Software. Inputwill be made easier if the additions andcorrections are clearly indicated. Refer toequipment by facility number, followed bythe unit number, (that is, 4355-l). If theequipment does not have a unit number,assign one to it — for example, "1," "2,""3" – up to the total number of units inthe facility. Status of Equipment is either:● I - In Service,● D - Decommissioned,● M - Mothballed, or● R - Under Repair.

H.4.1.2 The condition assessment of eachunit is based on page 3 of the Air Condi-tioning and Refrigerant Equipment Form(Attachment 3) and page 5 of the WaterChillers Form (Attachment 2).

H.4.2 Complete Part IIPart II is for recording service informationthat may be available at the site of theequipment. This information is then usedto verify and update the WIMS RefrigerantManagement Software.

H.4.2.1 Line 2- Complete Part II, Ser-vice Data if this information is available in

a service log book kept near the unit.Transfer this information to the WIMSRefrigerant Management Software. An up-to-date service log is required by EPA. Ifno service log is currently kept, oneshould be started as soon as possible. SeeAppendix G, Work Information Manage-ment System (WIMS), for information onsetting up a service log in WIMS and theuse of WIMS to track refrigerant con-sumption.

H.4.2.2 Line 2A - Record the two mostrecent additions of refrigerant. This in-formation will be used to compute theunit’s refrigerant consumption rate. Therefrigerant consumption rate will determinewhat, if any, action is required to complywith the EPA regulations.

H.4.2.3 Line 2B - Use this section to re-cord rebuilds, major repairs, or overhaulsperformed on the machine over the pastfive years. This information will be usedto gauge the cost of maintaining this ma-chine, and to project future major servicework. It will affect the schedule for re-placement or retrofit.

H.4.3 Complete Part IIInformation recorded in Part 111 is used toassess the condition of the room containingthe AC/R Equipment.

H.4.3.1 ETL 91-7 requires ASHRAE15-1992, Safety Code for MechanicalRefrigeration be followed for new constru-ction or when chillers are retrofitted orreplaced (see also Appendix J, Applicationof ASHRAE Equipment Room Design Re-quirements). A preliminary assessment ofthe mechanical room is necessary to

H-3


estimate the cost of renovating the room tomeet ASHRAE 15-1992. It is also usefulto identify difficulties in replacing thechiller. To complete:

H.4.3.2 Line 3 - If the chiller is locatedoutside, skip to the next section.

H.4.3.3 Line 3A - Make a quick (free-hand, five-minute maximum time-effort)sketch of the mechanical room containingthe chiller, noting the following wherethey exist (all dimensions should be visualestimates):

H.4.3.3.1 Room dimensions and height -Example: 40’(L) x 25’(W) x 15’(H). Thisinformation will be used to estimate venti-lation requirements.

H.4.3.3.2 Door locations and sizes - Thiswill indicate a removal path for the chillerand how the room might be modified tocomply with ASHRAE 15-1994.

H.4.3.3.3 Louver locations and sizes andExhaust fan locations and sizes - This willindicate the capacity of the existing venti-lation systems for comparison withASHRAE 15-1994 requirements.

H.4.3.3.4 Open floor area for new equip-ment - This will indicate the amount ofextra space available to locate additionalchillers or pumps (if desired).

H.4.3.3.5 Flame-producing equipment -Provide a brief description of the type andlocation of flame-producing equipment inthe room. This is any piece of equipmentproducing a visible open flame, eitherinternal or external to the equipment.Examples: boilers, unit heaters, waterheaters, door heaters which are gas- or oil-fired.) Note if: (1) it is separated from the

chiller by a wall with a door and (2) itscombustion air is ducted in from outsidethe room.

H.4.3.3.6 Refrigerant or oxygen monitors- Show types, manufacturer, model num-ber, and locations of each refrigerant oroxygen monitor. A refrigerant monitor isan instrument which measures the con-centration of refrigerant in the room. It islikely to be mounted on a wall near thechiller and may have remote sensors locat-ed at the base of the chiller. An oxygensensor is an instrument which measures theconcentration of oxygen in the room. It isnecessary for use with refrigerants such asCFC-11, CFC-12, HCFC-22, CFC-113,CFC-500, and CFC-502 whose predomi-nant exposure hazard is asphyxiation (de-pletion of oxygen). Oxygen sensors aretypically wall-mounted.

H.4.3.3.7 Self-contained breathing ap-paratus (SCBA) - Show the location ofSCBA apparatus. A self-contained breath-ing apparatus is used for entering themechanical room in an emergency situationfollowing a release of refrigerant withinthe room. It should be located in a promi-nent location near the entrance to themechanical room.

H.4.3.3.8 Exterior walls - Show exteriorwalls. They indicate how the mechanicalroom might be expanded to accommodatemore equipment, or modified to complywith ASHRAE 15-1994.

H.4.3.3.9 Chiller location - Show chillerlocation. Chiller locations indicate the easeof replacement and compliance withASHRAE 15-1994.

H-4


H.4.3.4 Line 3B (Water Chiller Formonly) - Rank the relative ease of replacingthe chiller according to the followingdefinitions:● Easy - little disassembly required and

little disturbance to equipment, walls,or structures;

● Moderate - some disassembly requiredand/or some disturbance to equipment,walls, or structures; and

● Difficult - major disassembly requiredand/or major disturbance to equipment,walls, or structures.

H.4.3.5 Line 3C (Water Chiller Formonly) - Briefly describe what appears to bethe easiest way to get the chiller out of theroom. How much disassembly would berequired? What equipment would need tobe moved out of the way? What buildingwalls or structures would need to be al-tered, and, if a multi-chiller installation, inwhat order would they need to be remov-ed?

H.4.4 Complete Part IVPart IV requires the surveyor to assess thecondition of AC/R equipment.

H.4.4.1 Line 4 - Compressor full loadamps (FLA) and volts are found on themain equipment tag. These will be used toestimate the existing full load efficiency.

H.4.4.2 Line 5 - (Water Chiller Form)CFC-11, CFC-113, and HCFC-123 are“low-pressure refrigerants”. This meansthat the operating pressure within theevaporator is less than atmospheric. It isrecommended they be equipped with high-efficiency purge units and evaporatorheater/pressurization systems.

H.4.4.2.1 Line 5A - Is the unit equippedwith an evaporator heater/pressurizationsystem? An evaporator heater/press-urization system is used to elevate thepressure in the evaporator during idleperiods so that air will not be drawn intothe machine through any leaks that may bepresent. (See Appendix E, Equipment toReduce Refrigerant Release During Main-tenance and Operation of Air Conditioningand Refrigeration Systems, for furtherexplanation and types of systems.)

H.4.4.2.2 Line 5B - Is the unit equippedwith a purge unit? A purge unit is a devicethat removes air from the refrigerant inorder to improve performance and reducecorrosion of the internal surfaces. (SeeAppendix E for further explanation ontypes of purge units and their efficiencies.)

H.4.4.2.2.1 Line 5B1- The efficiency ofpurge units (ability to contain refrigerantwhile extracting air) varies greatly amongindividual units. Older units are, typically,far less efficient than newer units. The tagdata you provide will help determine if thepurge is losing excessive refrigerant andshould be replaced.

H.4.4.2.2.2 Line 5B2 - Knowing how thepurge unit is being operated is essential toestimating the leakage on the low-pressureside of the machine.

H.4.4.2.2.3 Line 5B3 - The discharge ofa purge unit is capable of a significant re-frigerant release. For this reason it mustbe piped to the outdoors.

H.4.4.2.2.4 Line 5B4 - If “high efficien-cy” is stated somewhere on the purge, note

H-5


it here. (See Appendix E for more infor-mation on purge units and purge unitefficiency.)

H.4.4.2.3 Line 5C - The hour meter on apurge unit records the time the unit wasactively venting. Logging of purge run-time is highly recommended.

H.4.4.2.3.1 Line 5C1 - Record currentreading of the hour meter.

H.4.4.2.3.2 Line 5C2 - A recent recordof purge unit operation will be useful inestimating the leakage on the low-pressureside of the machine. (See Appendix F,Refrigerant Leak Mitigation throughEquipment Maintenance and Service Prac-tices, for more information on acceptablepurge unit run-time.)

H.4.4.3 Line 6 - Record the current read-ing on the chiller run-time hour meter, ifavailable. A record of the run-time will beuseful in estimating load and operatingcosts for the evaluation of replacement orretrofit alternatives.

H.4.4.4 Line 7 - A pressure-relievingdevice is installed on all water chillers toprevent over-pressurization. This can beeither a rupture disk or a combinationrupture disk and pressure relief valve.

H.4.4.4.1 Line 7A - Pressure relief forwater chillers is required to be piped to theoutside. Exposure to refrigerants is ahealth hazard.

H.4.4.4.2 Line 7B - A pressure-reliefvalve is recommended in the vent piping.

It should automatically reseat after activa-tion to prevent loss of a total refrigerantcharge should the rupture disk fail.

H.4.4.4.3 Line 7C - A rupture disk is apressure-relieving device incapable ofreseating itself.

H.4.4.4.4 Line 7D - A properly installedvent system will have a rupture disk be-tween the chiller and a self-reseating pres-sure-relief valve. The purpose of the rup-ture disk is to protect the valve from cor-rosion and possible reseating problems.There should be a way to tell if the rupturedisk has burst so that it can be replaced.

H.4.4.5 Line 8 - An important outcomeof this survey is the identification of re-frigerant leaks. All potential leak points,such as brazed and welded joints, gaskets,flanges, shaft seals, and valve stems,should be tested. Identify the leak locationson the chiller with either a marker or atag. EPA defines a “major” leak repair asinvolving the removal of major compo-nents such as the compressor, condenser,evaporator, or auxiliary heat exchangercoil. A “minor” leak repair does not entailthe removal of major components. Majorleaks require immediate action as dis-cussed in line 14J. Minor leak repairsshould be performed by maintenance per-sonnel as soon as possible.

H.4.4.5.1 Line 8A -minor leaks found. Aabove.

H.4.4.5.2 Line 8B -major leaks found. Aabove.

List the number ofminor leak is defined

List the number ofmajor leak is defined

H-6


H.4.4.5.3 Line 8C - Provide a brief de-scription of the leak (for example, com-pressor shaft seal, liquid line filter-drier,valve stem on compressor service shut-offvalve, inlet flange on condenser, tubingconnection). Indicate whether the leakrequires “major” or “minor” repair, asdefined above.

H.4.4.6 Line 9 - The type of facilityserved by this chiller indicates the systemload profile, or the cooling load demandover time. This information will be used inthe selection and staging of replacementalternatives.

H.4.4.7 Line 10 - It is useful to know ifthe chilled water system is already a cen-tral plant (serving more than one facility).Identifying central plants by circling themon the plan will assist in the analyses tofollow.

H.4.4.8 Line 11 - Whether or not thischiller is part of a multi-chiller plant issignificant in the selection and schedulingof replacement or retrofit alternatives.Multi-chiller plants can be identified by ashared, chilled water supply header.

H.4.4.8.1 Line 11A - Enter the unit num-bers of all other units sharing the samechilled water supply header. Check to seethey are correctly located on the Base SitePlan.

H.4.4.8.2 Line 1123 - This informationwill be used to estimate the least-costreplacement or retrofit scenario for thechiller plant.

H.4.4.9 Line 12 - Water-cooled chillershave condenser water piping leading to acooling tower. Air-cooled chillers haverefrigerant piping leading to a condensingunit, usually mounted on the same frame.

H.4.4.9.1 Line 12A - A “dedicated” cool-ing tower serves only this chilled watersystem. A “central” cooling tower servesmore than one chilled water system.

H.4.4.9.2 Line 12B - Provide a brief de-scription of the type and number of tow-ers. Copy important tag data such as man-ufacturer, model, serial no., unit no., andyear manufactured.

H.4.4.9.3 Line 12C - Assess the generalcondition of the cooling tower(s) usingassessment codes as defined on the surveyform.

H.4.4.9.4 Line 12D - Provide a brief de-scription of the type of condensing unitand its condition. For example: Are allfans operational? Are finned surfacesstraight and clean? Is the unit structurallysound? Copy important tag data such asmanufacturer, model, serial number, unitnumber, and year manufactured.

H.4.4.9.5 Line 12E - Assess the generalcondition of the condensing unit usingassessment codes as defined in line 12C ofthe survey form.

H.4.4.10 Line 13 - Use this space to con-tinue your responses to this section, or tomake additional comments regarding yourinspection of the equipment.

H-7


H.4.5 Complete Part VPart V is for noting specific conditionswhich contribute to leakage or are a risk tohealth and safety and should be correctedas soon as possible.

H.4.5.1 Line 14 - By following the in-structions on the survey form, most of the“Action Items” applicable to this chillershould be checked by the completion ofthis survey. Facility Number, Unit Num-ber, Surveyor, Date, and Base informationneed to be repeated at the top of page 6.This page can then be distributed separate-ly from the other pages of the form. Eachof these action items contribute directly torefrigerant leakage or as a risk to healthand safety. Every action item “checked”should be corrected by maintenance per-sonnel as soon as possible.

H.4.5.1.1 Line 14A - For line 5A, aninspection was made to determine whetherthe low-pressure machine had an heater/-pressurization system on the evaporator.Check this box if line 5A was marked“No. “

H.4.5.1.2 Line 14B - For line 5B, thepurge unit was surveyed. If this is a low-pressure chiller, and does not have a purgeunit, one must be installed. Check this boxif line 5B was marked “No. ”

H.4.5.1.3 Line 14C - For line 5B3,whether or not the purge discharge waspiped to the outside was determined.Check this box if line 5B3 was marked“No.”

H.4.5.1.4 Line 14D - For line 5B4, itwas determined whether or not the purge

was a high-efficiency type. Check this boxif line 5B4 was marked “No. ”

H.4.5.1.5 Line 14E - For line 7A, it wasdetermined whether or not the pressurerelief for the evaporator and condenserwas piped to the outside. Check this box ifline 7A was marked “No. ”

H.4.5.1.6 Line 14F - For line 7B, it wasdetermined whether or not a pressure reliefvalve was installed in the vent pipe for theevaporator and condenser. Check this boxif line 7B was marked “No.”

H.4.5.1.7 Line 14G - For lines 7C and7D, it was determined whether or not arupture disk was installed in (1) the ventpipe for the evaporator and condenser and(2) whether or not it was installed betweenthe chiller and the pressure relieve valve.Check this box if either line 7C or 7D wasmarked “No. ”

H.4.5.1.8 Line 14H - Check this box ifinformation was obtained for lines 2A and2B, or if service data for this unit is notcurrently being logged on the WIMS Re-frigerant Management Software.

H.4.5.1.9 Line 14I- Check this box ifany “minor” leaks were found (refer toline 8A).

H.4.5.1.10 Line 14J - Check this box ifany “major” leaks were found (refer toline 8B). Determine whether the leaksrequiring a major repair effort are signifi-cant in terms of refrigerant loss. If leaksare obviously significant, mark the unit forimmediate retirement. If the significanceof the leak cannot be determined, mark the

H-8


unit for further evaluation (fixing all minor retirement (that is, develop a plan forleaks and closely tracking consumption). If retirement and have it retired in one yearEPA leak rate requirements cannot be met, per EPA requirements).schedule the equipment for immediate

H-9 (H-10 Blank)


AC/R EQUIPMENT SURVEY - UTILITIES DATA SHEET

**************************************************************************UTILITY USE AND COST DATA FOR THE PRECEDING 12 MONTH PERIOD

**************************************************************************

Your Name: Base: Date:

Description of Service:

Name & Address of Utility:

Service Rep.: Phone No.:

TOTALS XXXXXXXXX

Attach aperiod.

Remarks:

copy of the rate schedule effective for the prcedeing 12 month

BILLING PERIOD CONSUMPTION DEMAND COST

FROM TO # DAYS UNITS: (NEAREST $) $/UNIT

Page 1 of 1 Appendix H - Attachment 1


AC/R EQUIPMENT SURVEY FORM

FOR WATER CHILLERS

Surveyor: Date: Base:

***************************************************************************I. GENERAL DATA

***************************************************************************

1. Complete the following.

Facility Number:

Description:

Capacity: (Tons, HP)

Refrigerant Qty: (lb)

Manufacturer:

Serial #:

Condition Assessment (See 12.C for

Unit No.:

Status of Equipment:

Date Mfg’d:

Refrigerant Type: R -

Model:

Definitions) :

Description of Load: [ ]Comfort Cooling [ ]Process Cooling

Is chiller located correctly on the Base Site Plan? [No, Yes]Make correction on the plan <

Remarks:

***************************************************************************II. SERVICE DATA

***************************************************************************

2. Complete the following for service work performed recently.

A. Refrigerant Added:

Quantity: (lb) Hour Meter:


Date:

Date:

B. Major Service Work (rebuilds, major repairs, overhaul):



FOR WATER CHILLERS

*************************************************************************III. ASSESSMENT OF MECHANICAL ROOM

***************************************************************************

3. Is the chiller located in a mechanical room? . . . . . [No, Yes]Skip to 4 <

> A. Sketch the room below. Note the following.

*****

Room dimensions & height *Door locations & sizes *Louver locations & sizes *Exhaust fan locations & sizes *Open floor area for new equip. *

Flame-producing equipmentRefrig. or oxygen monitorsSelf-contained breathing App.Exterior wallsChiller location

> B. Ease of Replacement: [ ]Easy [ ]Moderate [ ]Difficult

> C. Briefly describe the work required to replace chiller:

Appendix H - Attachment 2 Page 2 of 6


FOR WATER CHILLERS

***************************************************************************IV. ASSESSMENT OF EQUIPMENT

***************************************************************************

4. Compressor Full Load Amps (FLA): volts :

5. Is chiller low-pressure (R-n, or R-113)? . . . . . . . [No, Yes]

> A. Heater/Pressurization System on Evaporator?. . . . . . [No, Yes]Check Action Item A (last page) <

> B. Does chiller have a purge? . . . . . . . . . . . . [No, Yes]Check Action Item B (last page) <

>

>

>

>

>

> C.

1.

2.

6. Does

1.

2.

3.

4.

Manufacturer: Year Built:

Model: Serial #:

Other:

Mode of operation: . . . . . . . [Manual, Off, Auto, ?]

Is discharge piped to outdoors? . . . . . . . . [No, Yes]Check Action Item C (last page) <

Is purge high-efficiency type? . . . . . . [No, ?, Yes]Check Action Item D

Does purge have an hourIf yes:

(last page) <

meter? . . . . . . . . . [No, Yes]

Current reading:

Past three readings (if logged):

Date: Reading:

Date: Reading:

Date: Reading:

chiller have a run-hour meter? . . . . . . . . . .[No, Yes]Current reading: <



FOR WATER CHILLERS

7. Pressure-relief for evaporator and condenser:

A. Vent piped to outside? . . . . . . . . . [No, Yes]Check Action Item E (last page) <

B. Pressure-relief valve (PRV) installed? . . . . . .[No, Yes]Check Action

C. Rupture diskCheck Action

D. Rupture diskCheck Action

8. Survey the chiller

Item F (last page) <

installed? . . . . . . [No, Yes]Item G (last page) <

installed between chiller & PRV? . . .[No, Yes]Item G (last page) <

with portable leak detector. Mark each leaklocation with a tag or marker. (See Survey Guide for definition ofmajor and minor leaks.

A. How many minor leaks were found?Check Action Item I (last page) if any <

B. How many major leaks were found?Check Action Item J (last page) if any <

C. Briefly describe the leaks:

9. Identify each & every type of

StorageClubDiningCommunityHospitalLiving QuartersRetail Store

facility served by this chiller.

Maintenance ShopsAssembly HallsTraining/SchoolClinics & DispensariesLarge Offices (> 8,000 SF)Small Offices (< 8,000 SF)

10. Is chiller serving more than one building? . . . . . . [No, Yes]Circle buildings served on base plan <

11. Are other chillers serving the same load? . . . . . . [No, Yes]If yes:

A. Enter their unit numbers:

B. Are they located in the same room? [No, Yes]



FOR WATER CHILLERS

12. Is the chiller water cooled? . . . . . . . . . . . . . [No, Yes]

13.

> A. Cooling tower(s) serves this system only? . . . . [No, Yes]

> B. Describe the cooling tower(s):

> C. Condition Assessment Code for Cooling Tower(s):

1 =

2 =

3 =

4 =

Fully Operational Condition. System isreliable and fully functional.Operational Condition. Routine preventive main-tenance is required to preserve reliability.Serious but Tolerable Condition. Failure isprobable, but work-arounds can be established.Intolerable Condition. Major componentshave failed or failure is-imminefit.

> D. Briefly describe condensing unit:

> E. Condition Assessment Code for Condensing Unit:

Remarks:



FOR WATER CHILLERS

Facility Number: Unit Number:


***************************************************************************v. ACTION ITEMS

***************************************************************************

14. Check items below which require immediate action. Give a copy ofthis page to the Base Refrigerant Manager.

A.

B.

C.

D.

E.

F.

G.

H.

I.

J.

o Install a Heater/Pressurization System on Evaporator

o Install High-Efficiency Purge Unit

oooooooo

Appendix H - Attachment 2

Pipe Purge Discharge to Outside

Verify if Purge is High-Efficiency Type. If Not,Replace with a High-Efficiency type.

Pipe Pressure-Relief Vent for Evaporator andCondenser Outside

Install Pressure Relief Valve (PRV) in Vent Pipe forEvaporator and Condenser

Install Rupture Disk in Vent Pipe for Evaporator andCondenser. Install Upstream of PRV.

Start/update an equipment service log on the WIMS.

Repair Minor Refrigerant Leaks

Major leaks found - repair, retire, or scheduleretirement of the unit within 30 days. See Appendix Bof the Refrigerant Management Handbook for moreinformation.

Page 6 of 6


FOR AIR CONDITIONING AND REFRIGERATION EQUIPMENT


***************************************************************************I. GENERAL DATA

***************************************************************************

1. Complete the following.

Facility Number: Unit No.:

Description: Status of Equipment:

Capacity: (Tons, HP) Date Mfg’d:

Refrigerant Qty: (lbs) Refrigerant Type: R -

Manufacturer: Mode 1:

Serial #:

Condition Assessment (See Page 3 for Definitions):

Description of Load: [ ]Air Conditioning [ ]Refrigeration

Is unit locatedMake correction

Remarks:

correctly on the Base Site Plan? [No, Yes]on the plan <

***************************************************************************II. SERVICE DATA

***************************************************************************

2. Complete the following for service work performed recently.

A. Refrigerant Added:



B. Major Service Work (rebuilds, major

Date:

Date:

repairs, overhaul) :




*************************************************************************III. ASSESSMENT OF MECHANICAL ROOM

***************************************************************************

3. Is the unit located in a room? . . . . . . . . . . . . [No, Yes]Skip to 4 <

> A. Sketch the room below. Note the following.

****

Room dimensions & height * Flame-producing equipmentDoor locations & sizes * Refrig. or oxygen monitorsLouver locations & sizes * Self-contained breathing App.Exhaust fan locations & sizes * Exterior walls

* Unit location




***************************************************************************IV. ASSESSMENT OF EQUIPMENT

***************************************************************************

4. Compressor Data (if separate from other components):

Manufacturer: Model No.:

Serial No.: Year Built:

Full Load Amps (FLA): volts :

Condition Assessment (See Code Descriptions Below):

Remarks:

5. Evaporator/Air Handling Unit Data (if separate from othercomponents) :




Remarks:

6. Condensing Unit/Cooling Tower Data (if separate from othercomponents) :




Remarks:

*********** Condition Assessment Code Descriptions ************ 1 = Fully Operational Condition. System is ** reliable and fully functional. ** 2 = Operational Condition. Routine preventive ** maintenance is required to preserve reliability. ** 3 = Serious but Tolerable Condition. Failure is ** probable, but work-arounds can be established. ** 4 = Intolerable Condition. Major components ** have failed or failure is imminent. *****************************************************************




7. Survey each component of the system with portable leak detecto.Mark each leak location with a tag or marker.

A. How many leaks were found?Check Action Item B (last page) if any <

B. Briefly describe the leaks:

----------------------------------------------------------------------

Facility Number: Unit Number:


***************************************************************************v. ACTION ITEMS

***************************************************************************

8. Check items below which require immediate action. Give a copy ofthis page to the Base Refrigerant Manager.

A. o Start/update an equipment service log on the WIMS.

B. o Repair Refrigerant Leaks


Appendix 1 — Funding Alternatives for Base Refrigerant Management Program

Appendix I — Funding Alternatives forBase Refrigerant Management Program

ABSTRACT: This appendix provides information on obtaining alternative funding for projectsin support of the Base Refrigerant Management Program (BRMP). The three specializedprograms are the Energy Conservation Investment Program (ECIP), the Federal EnergyManagement Program (FEMP), and the Pollution Prevention Program (PPP).

I. 1 Introduction

This chapter contains information onfunding sources for equipment, tools,management initiatives, and facility con-tracts supporting a BRMP. The threespecialized programs to support suchprojects are ECIP, FEMP, and PPP. Thisappendix provides a description of thesethree programs, as well as specific exam-ples on how to accomplish the paperworkto justify a project for any of these fundingavenues. These programs have specificadvocates and points of contact (POC) ateach base and major command(MAJCOM). All actions involving theseprograms must be coordinated with theseadvocates.

1.2 Program Definitions

1.2.1 Energy Conservation InvestmentProgram

The ECIP is a Military Construction(MILCON)-funded program to improvethe energy efficiency of existing Depart-ment of Defense (DoD) facilities. Theprojects funded through ECIP improve theliving and working environment of DoDpersonnel, enhance mission capabilities,and greatly decrease the negative

environmental effects of DoD energysystems. In the Air Force, the specificpurpose is to help bases reduce energyconsumption and costs, provide savings inoperating costs, and achieve the energygoals. This includes construction of new,high-efficiency energy systems or theimprovement and modernization of existingsystems. Public Law 102-486 makes eachmilitary service responsible for identifyingand accomplishing all energy conservationmeasures with a payback period of tenyears or less.

1.2.2 Federal Energy ManagementProgram

The FEMP is a MILCON and/or Opera-tions and Maintenance-funded programthat covers energy conservation, renewableenergy, and water efficiency projects. Italso covers the identification and design ofthese projects and the program support,such as training and awareness. FEMP canbe used to fund Military Family Housing(MFH) projects.

1.2.3 Pollution Prevention ProgramThe PPP program includes all work neces-sary to eliminate or reduce undesirableimpacts on human health and the environ-ment to include the use of processes,

I-1

Appendix I — Funding Alternatives for Base Refrigerant Management Program

practices, products, or management ac-tions. PPP requirements span the AirForce budget with finding in such appro-priations as: Military Construction (3300);Operations and Maintenance (O&M)(3400); Research, Development, Testing,and Evaluation (RDT&E) (3600); AircraftProcurement (3010); Missile Procurement(3020); and Other Procurement (3080).Program and budget pollution preventionproject requirements in accordance withthe associated rules for each appropriation.The functional offices of primary responsi-bility (OPRs) are responsible for require-ment advocacy with civil engineering asthe lead agency for PPP consolidation,tracking, and management.

1.3

1.3.1

Criteria for Each Program

ECIP and FEMP ProgrammingCriteria

Priority is given to projects that producethe highest savings-to-investment ratio(SIR) and the discounted payback (DPB)period. SIR and DPB are terms used withlife-cycle cost analyses. For more detailsee section I.4, Justification and Documen-tation. Projects must have a SIR greaterthan 1.25 and a DPB of ten years or less.Additional consideration can be given toprojects that substitute renewable energyfor nonrenewable energy. Because there isuncertainty over future force levels andbase structure, a sensitivity analysis mustbe conducted to determine if there is likeli-hood that expected changes might alter theeconomic benefits. Increased risk identi-fied as the result of a sensitivity analysismay be used to lower a project’s program-ming priority.

1.3.2 PPP Programming CriteriaPPP requirements can be divided intorecurring and nonrecurring categories.

1.3.2.1 Recurring: pollution preventionoperations and services (O&S). Annualrecurring, “must do” services and projectsare associated with “keeping the gatesopen. ” Recurring, “must do” requirementsinclude:

● periodic updates of management plansand analyses of pollution preventioninitiatives required by law or policy;

● baseline survey updates;● other overhead costs;● education, training, and awareness pro-

grams;● operations and maintenance costs for

PPP tracking systems and hazardousmaterial pharmacies;

● pollution prevention opportunity assess-ments; and

● environmental certifications and licens-es, only as part of a mandatory trainingcourse.

1.3.2.2 Nonrecurring requirements aredivided into three levels: P1, P2, and P3.P1 includes projects and services that:● eliminate dependence on ozone deplet-

ing chemicals;● satisfy federal, state, and local pollu-

tion prevention laws and regulations;and

● satisfy pollution prevention ExecutiveOrders.

P2 requirements are those required to meetfuture federal or DoD legal requirementsor Air Force Pollution Prevention ActionPlan goals, objectives, and sub-objectives.

I-2


P3 projects and services go beyond AirForce Pollution Prevention Action Plangoals, DoD goals, and legal requirements.The BRMP requirements will probably fallunder level PI. The following are nonre-curring projects and services.●

●

●

Projects which reduce/eliminate the AirForce demand for ozone depletingcompounds (ODCs). Typical ODCprojects include: halon and refrigerantrecyclers and reclamation costs, airconditioner purge units/heaters, aque-ous parts washers, storage containersfor ODC banking, limited air condi-tioner retrofits from chlorofluorocarbon(CFC) to hydrochlorofluorocarbon(HCFC) (if they are cost-effective; noODC inventory exists and no recy-clable ODC market exists), leak detec-tors, and automatic shutoff valves.Pollution prevention managementplans, where required by law.Projects to find acceptable materialsand processes to replace existing mate-rials and processes in facilities.

I.3.2.3 Requirements not eligible for PPPinclude, but are not limited to the follow-ing types of projects.●

●

●

●

Nonenvironmental projects-projectsprimarily justified for nonenviron-mental reasons which include environ-mental requirements in scope.Maintenance projects-resulting frompoor infrastructure maintenance.Air conditioning projects—replacing airconditioning equipment using CFCswith HCFCs, unless criteria in para-graph 1.3.2.2 is met.Depot-level equipment-the DefenseBusiness Maintenance Area (DBMA) inthe Defense Business Operations Fund

has been established to pay for thereplacement of depot-level equipmentcosting more than $25,000. Equipmentmeeting this definition should be bud-geted through the DBMA capital assetbudget.

● Acquisition projects.● Energy conservation MILCON pro-

jects.

1.4 Justification andDocumentation

I.4.1 ECIP and FEMP Justificationand Documentation Process

Facility energy conservation retrofit pro-jects costing $300,000 or more are admin-istered through the ECIP program asMILCON projects. FEMP follows thesesame roles but also includes O&M. Pro-jects are evaluated on the basis of highestSIR, as calculated by the life-cycle costmethod contained in this guidance. Pro-jects must meet the following program-ming criteria.●

●

●

Projects are ranked on the basis of thegreatest potential life-cycle cost pay-back, as indicated by the SIR and pay-back period. Additional considerationis given to projects that substituterenewable energy for nonrenewableenergy.Projects must have a SIR greater than1.25 and discounted payback period often years or less.The basic objectives of ECIP are ener-gy conservation and energy cost sav-ings. In order for a project to be eligi-ble for the program, at least 20 percentof its annual dollar savings must beattributed to energy British thermal unit(Btu) savings.

I-3

Appendix I – Funding Alternatives for Base Refrigerant Management Program

I.4.2 Economic AnalysisEach discrete portion of the project mustbe life-cycle cost-effective or essential toaccomplishment of the other portions ofthe project. Care must be taken to ensureenergy savings are not credited to multipleprojects.

I.4.2.1 Life-cycle cost (LCC) analysismust follow the criteria and standardscontained in "Tri-Service Memorandum ofAgreement on Criteria/Standards for Eco-nomic Analysis/Life-Cycle Costing forMILCON Design," Attachment 1. TheConstruction Engineering Research Labo-ratory (CERL) computer program LifeCycle Cost in Design (LCCID), is recom-mended. The program was mailed to theMAJCOM Energy engineers on 27 May1993.

I.4.2.2 Other tools that can assist in theeconomic analysis are:

● “Life-Cycle Costing Manual for theFederal Energy Management Pro-gram, ” NIST Handbook 135 (currentversion 1987), and

● NIST Building Life-Cycle Cost (BLCC)computer program, version 4.1 (1994).

Available by calling Advance Sciences,Inc., at (703) 243-4900. Also helpful is thedocument

Present Worth Factors for Life-CycleCost Studies in the Department ofDefense, NISTIR 4942-1 (current ver-sion 1994). Included in this documentis a Memorandum of Agreement onCriteria/Standards for Economic Analy-sis/Life Cycle Costing for MILCON De-sign, dated March 18, 1991, which

includes further information on thebasic life-cycle analysis assumptionsand criteria.

I.4.2.3 A recommended simplified eco-nomic analysis summary format is provid-ed in Attachment 2 of this appendix. Inusing this form all costs are determined asof the date the analysis is made.

I.4.2.4 A LCC analysis for each overallproject and for each discrete retrofit action(for example, storm windows, insulation,economizer) included within the projectwill be performed and included with theDD form 1391 project documents submit-ted for consideration. In preparing ananalysis:●

●

●

●

base it on an economic life of 25 yearsor the anticipated life of the retrofitaction or facility, whichever is less(Attachment 3);use the actual current cost of energy atthe facility;for the purpose of ranking qualifiedprojects, all discounted dollar savings(100 percent) will be used for comput-ing the SIR;the estimated construction cost. laborand material costs, and the actual cur-rent unit costs of the energy at thefacility analyzed (cost to the govern-ment, not stock fund prices) will beused as the basis for all LCC calcula-tions.

I.4.3 Project DocumentationProject submittal will include the follow-ing.

I-4


I.4.3.1 DD Form 1391 with the normalMILCON line item detail. DD Form 1391will include the notation ECIP at thebeginning of the title block and a line itemidentification, description, location, currentworking estimate (CWE), total projectSIR, annual dollar savings, and energysavings in million British thermal units(MBtu).

I.4.3.2 Classification of projects underone of the ten categories listed in Attach-ment 3. A project is classified in a catego-ry if 75 percent of the scope of the projectfalls into the category. Projects which donot contain 75 percent on any one categoryshall be identified as “Facility EnergyImprovement. ”

I.4.3.3 A copy of all the life-cycle analy-ses for each discrete portion and for theoverall project. Use the format provided inAttachment 2 for reporting the LCC analy-sis on DD Form 1391c.

I.4.3.4 Supporting documentation consist-ing of basic assumptions and basic engi-neering and economic calculations showinghow savings were determined. Computer-generated summaries are acceptable, pro-vided they conform to the above guidance.

I.4.3.5 Use metric units in support of thegoals established under the ExecutiveOrder 12770 Metric Usage in FederalGovernment Programs, dated 25 July1991.

I.4.3.6 Clearly defined conservation mea-sures that will provide the energy savingsand the specific facilities affected by theproject.

I.4.3.7 A statement regarding whether ornot the installation affected by the projectis being considered for closure or realign-ment. If so, provide an explanation whythe project should be considered in light ofthe closure or realignment.

I.4.3.8 A detailed statement on how youplan to verify savings after the project isoperational/installed.

I.4.3.9 Electronic input via ‘PDC,’ con-sisting of the program initial input screenwith Program Type - 'ECP' and PDP =ECIP, plus DD Form 1391.

I.4.4 Program CredibilityTo maintain the program credibility of theECIP and FEMP and provide and explaincurrent project data which are not inagreement with data as approved by Con-gress, it is essential that documentation bediligently maintained by installations,MAJCOMS, and design and constructionagents. This documentation should include,for example, scope and scope changes,design projections, and auditable trails ofcost, cost avoidance, energy savings, SIRS,and simple amortization. Each level ofcommand should assist in maintaining theaudit trails to provide quick, positiveresponses to DoD and Congress.

I.4.5 Management ResponsibilitiesEach organization, within its area of re-sponsibility, ensures:● Projects are included in the ECIP and

FEMP at a rate appropriate to accom-plish the objectives of the NationalEnergy Conservation Policy Act andthe objectives of DoD criteria.

I-5

Appendix I – Funding Alternatives for Base Refrigerant Management Program

●

●

●

●

●

All projects are designed and construct-ed within the original scope as submit-ted to Office of the Secretary of De-fense (OSD) and Congress.Adherence to this guidance will notdecrease the program efforts to contin-ue accomplishment of all cost-effective,low cost/no cost, energy conservationactions which might serve to reduce thescope of an ECIP or FEMP project.Funds authorized and appropriated forECIP and FEMP projects are notdiverted or reprogrammed withoutspecific approval from DoD.Savings estimates and program criteriacompliance are recomputed, and re-ported to Systems Engineering Direc-torate Headquarters Civil EngineerSupport Division (HQ AFCESA/EN),whenever scope, savings, or cost esti-mates are changed by more than tenpercent.Readily auditable supporting documen-tation,- including basic engineering andeconomic calculations, are maintainedfor each project.

I.4.6 Energy Savings ConversionFactors

For the purpose of calculating energysavings, use the following conversion fac-tors:

Purchased electricity3,413 Btu/kWh 3.6 MJ/kWh

Purchased steam1,340 Btu/lb 1.41 MJ/lb

Distillate fuel oil138,700 Btu/gal 38.6 MJ/L

Natural gas1,031,000 Btu/ 38.85 MJ/cu mCu ft

LPG, propane, butane95,000 Btu/gal 24.6 MJ/L

Bituminous coal24,580,000 Btu/ 28,592 MJ/metric tonshort ton

Anthracite coal25,400,000 Btu/ 29,546 MJ/metric tonshort ton

Residual fuel oilAverage thermal content ofoil at each installation

I.4.6.1 Purchased energy is defined asbeing generated off-site. For special cases,where electric power or steam is obtainedfrom on-site sources, use the actual aver-age gross energy input to the generatingplant.

I.4.6.2 The term “coal” does not includelignite. Where lignite is involved, use theBureau of Mines average value for thesource field.

I.4.7 PPP Documentation ProcessPPP is a new program, being held to line-item approval through the Air Staff re-source allocation process. As such, line-item validation and avocation by theappropriate Air Staff oversight office isrequired so they can provide advocacy forthis program.

I.4.7.1 The required PPP documentationis included in the WIMS-EnvironmentalSystem Pollution Prevention (WIMS-ESPP) module.

I-6


I.4.7.2 No new PPP requirements can be (HQ USAF/CEVV) without a correspond-submitted to Prevention Division, ing A-106 listing. The WINS-ES PP mod-Directorate of Environmental Quality, ule includes additional data fields neededHeadquarters U.S. Air Force to manage projects.

I-7 (I-8 Blank)


ATTACHMENT 1

MEMORANDUM OF AGREEMENTON

CRITERIA/STANDARDS FOR ECONOMIC ANALYSES/LIFE-CYCLE COSTINGFOR MILCON DESIGN

I. PURPOSE

1.1 The purpose of this Memorandum of Agreement (MOA) is to establish criteria andstandards for performing economic analyses and life-cycle cost studies used in supportof design decisions for projects in the Military Construction (MILCON) Program (thatis, to support the selection from various alternatives of components/systems being con-sidered as elements in facilities design). These criteria and standards apply to all designdecisions regardless of when they are made in the planning, programming, design, andprocurement process. This agreement does not apply to economic analyses and life-cyclestudies used to make project-justification decisions during the planning and programmingprocess.

II GENERAL

2.1 Economic analyses shall be conducted as part of the design process to ensure that theselection/rejection of design alternatives is not based solely on construction costs, butalso on least life-cycle costs (LCC), that is, lowest total cost of ownership. The depthand degree of formality of these analyses shall be determined on a case-by-case basis toensure that the cost of performing an analysis is clearly outweighed by the potentialbenefits derived. Results of generic studies or results of previous analyses of alternativessimilar to those currently under consideration may be used in lieu of performing a newstudy, provided the previous study was based on similar design conditions, criteria, andmethods. Previous studies should be updated only as required to reflect changes of condi-tions significant enough to impact the design decision. All economic analyses and otherjustification for the selection of a design alternative, whether a previous study or a newone, shall be clearly documented in the appropriate section of the project design analysis.

III. METHODS

3.1 All analyses shall consider the total LCC for design alternatives, where the LCC includesall costs and benefits associated with an alternative over its expected life, including butnot limited to construction/procurement, energy, maintenance, operation, repair, replace-ment, alteration, disposal costs, and retention values. The present value discountingapproach shall be used to adjust for the differences in timing of costs and benefits unless

Page 1 of 3 Appendix I – Attachment 1

otherwise specified by other directives or by public law. The basic discount factor forfinding the present value of a future amount is calculated as follows:

Discount Factor = 1

( 1 + d )n

where: d =n =

appropriate discount rate, andthe time period over which the discounting is done.

Discounting should be applied to all costs and benefits over the appropriate analysis period.Specific criteria include:

a)

1)

2)

b)

c)

Discount Rates: The discount rates are expressed in “real” terms (i.e., over andabove the rate of inflation for the economy as a whole).

Nonenergy-Related Studies: An annual “real” discount rate of 10 percent shouldbe used in evaluating all nonenergy-related economic studies.

Energy-Related Studies: All energy-related economic studies (studies in whichenergy costs are relevant, regardless of their magnitude relative to other costs)shall use the current discount rate published by the National Institute of Standardsand Technology (NIST) in their annual supplement to NIST Handbook 135 anddisseminated by the appropriate Service Headquarters Office.

Analysis Period: The analysis period shall be the date of the study (DOS)through the economic life of the facility as a whole. The economic life shall notbe taken beyond 25 years from the scheduled beneficial occupancy date (BOD)for the project unless specifically approved by the appropriate Service Headquar-ters Office. Such approval cannot be granted for energy-related studies as it isprecluded by statute.

Cash Flow: In general, cash flow used in the analysis will be based on theestimated calendar dates on which the events and costs/benefits are project-ed/scheduled to occur. Construction/procurement costs may be assumed to beincurred as a single lump sum, preferably at the time corresponding to themidpoint of the construction/procurement process. Other cash flows that occurperiodically throughout the year (for example, cost of fuel, electricity, water,maintenance) may be assumed to be incurred as a single lump sum, preferably atmidyear. In the circumstances where the above assumptions add unnecessarily tothe complexity of the calculations, all cash flows maybe assumed to occur at theend of the year in which they are actually scheduled/projected to occur.

Appendix I – Attachment 1 Page 2 of 3

d) Benefits and Costs: All benefits and costs will be expressed in terms of constantdollars that reflect the purchasing power of the dollar on the DOS (i.e., constantDOS dollars). The rate of inflation of the economy as a whole will be excludedfrom all LCC calculations. (The rate of inflation is irrelevant to the LCC analysisresults since all benefits and costs are expressed in terms of constant DOS dollarsand discounted using a “real” discount rate which reflects the time value ofmoney over-and-above the general rate of inflation.)

e) Future Benefits and Costs: In projecting future benefits and costs, an allowancefor future price-level changes will be made only for particular benefits and costsexpected to change at rates higher or lower than the general rate of inflation. Insuch cases, the rates of change used in the analysis will be the “differential” rates(i.e., the anticipated differences between the actual projected rates of change andthe general inflation rate).

1) Nonenergy Studies: For nonenergy studies, the differential rate of future price-level change shall generally be assumed to be zero, except in those cases wherethere is reliable information/data to the contrary.

2) Energy Studies: Fuel/energy costs shall have differential escalation rates aspublished by NIST in Handbook 135 and disseminated as indicated in paragraph3.1.a (2) above. All nonenergy costs shall have a zero differential escalation rate.

IV. COMPUTER-AIDED CALCULATIONS

4.1 All computer-aided calculations for MILCON design economic studies will beaccomplished using the Life-Cycle Cost In Design (LCCID), a computer program foreconomic analysis developed by the U.S. Army Corps of Engineers ConstructionEngineering Research Laboratory (CERL) or a version thereof which has been certifiedby CERL as equivalent.

s i g n e d signed

RICHARD C. ARMSTRONG RUSSELL T. RESTON, ColonelChief Engineering Division SAF/FMCEDirectorate of Military Program HQ USAFHQUSACE

H. ZIMMERMANsigned

Assistant Commander forEngineering and DesignNAVFACENGCOM



ATTACHMENT 2

LIFE-CYCLE COST ANALYSIS SUMMARYEnergy Conservation Investment Project (ECIP) Program

LOCATION: REGION NO. PROJECT NUMBER:PROJECT TITLE: FISCAL YEAR:DISCRETE PORTION NAME:ANALYSIS DATE: ECONOMIC LIFE: YEARSPREPARED BY:

1. INVESTMENTA. CONSTRUCTION COST $B. SIOH $C. DESIGN COST $D. SALVAGE VALUE COST $E. TOTAL INVESTMENT (1A + lB + lC - lD) $

2. ENERGY SAVINGS (+) / COST (-)ANALYSIS DATE, ANNUAL SAVINGS, UNIT COST & DISCOUNTED SAVINGS

UNIT COST SAVINGS ANNUAL $ DISCOUNT DISCOUNTED$/MBtu (1) MBtu/YR (2) SAVINGS (3) FACTOR (4) SAVINGS (5)

FUEL

A. ELECT $ x = $ x = $

B. DIST $ x = $ x = $

C. RESID $ x = $ x = $

D. NAT G $ x = $ x = $

E. COAL $ x = $ x = $

F. TOTAL $ $

3. NON-ENERGY SAVINGS (+) / COST (-)A. ANNUAL RECURRING (+/-) $

(1) DISCOUNT FACTOR (TABLE A)(2) DISCOUNTED SAVINGS/COST (3A X 3A1) $

B. NON-ENERGY SAVINGS (+)/COST (-)

SAVINGS (+) YEAR OF DISCOUNT DISCOUNTED SAVING(+)ITEM COST (-) (1) OCCUR (2) FACTOR(3) COST (-) (4)

(1) $ $

(2) $ $

(3) $ $

(4) TOTAL $ $

4.

5.

6.

7.

C. TOTAL NON-ENERGY SAVINGS (+)/COST (-) (3A2+3B44) $

FIRST YEAR DOLLAR SAVINGS 2F3 +3A+(3B44/(YRS ECONOMIC LIFE)) $

TOTAL NET DISCOUNTED SAVINGS (2F5 +3C) $

SAVINGS TO INVESTMENT RATIO (SIR) = (5/1E) =

SIMPLE PAYBACK PERIOD (ESTIMATED) (SPB) = (lE/4) =


LOCATION: Price Suppor t C t r REGION NO. 2 PROJECT NUMBER: 38806

PROJECT TITLE: ECIP: Insulate Steam Lines FISCAL YEAR: YR1992

DISCRETE PORTION NAME: Insulate Warehouse Steam Distribution Lines

ANALYSIS DATE: AUG 1991 ECONOMIC LIFE: 25 YEARSPREPARED BY: J. Hooten

1. INVESTMENTA. CONSTRUCITON COST $200.800B. SIOH $ 12.048C. DESIGN COST $ 12,048D. SALVAGE VALUE COST $E. TOTAL INVESTMENT (1A + lB + lC - lD) $224,896

2. ENERGY SAVINGS (+) / COST (-)ANALYSIS DATE, ANNUAL SAVINGS, UNIT COST & DISCOUNTED SAVINGS

UNIT COST$/MBtu (1)

FUEL

A. ELEECT $ 16.23

B. DIST $

c. RESID $ 6.61

D. NAT G $

E. COAL $

F. TOTAL

SAVINGSMBtu/YR (2)

x 11 =

x =

x 27.919 =

x =

x =

27.930

ANNUAL $SAVINGS (3)

$ 179

$

$ 184.545

$

$

$ 184.724

DISCOUNT DISCOUNTEDFACTOR (4) SAVINGS (5)

x 15.85 = $ 2,830

x = $

x 28.23 = $ 5.209,694

x = $

x = $

$ 5.212.524

3. NON-ENERGY SAVINGS (+) / COST (-)A. ANNUAL RECURRING (+/-) $ 0

(1) DISCOUNT FACTOR (TABLE A)(2) DISCOUNTED SAVINGS/COST (3A X 3A1) $

B. NON-ENERGY SAVINGS ( +)/COST (-)

SAVINGS (+) YEAR OF DISCOUNT DISCOUNTED SAVING(+)ITEM COST (-) (1) OCCUR (2) FACTOR(3) COST ( - ) (4)

(1) $ $

(2) $ $

(3) $ $

(4) TOTAL $ $

C. TOTAL NON-ENERGY SAVINGS (+)/COST (-) (3A2+3B44) $

4. FIRST YEAR DOLLAR SAVINGS 2F3 + 3A+ (3B44/(YRS ECONOMIC LIFE)) $ 184.724

5. TOTAL NET DISCOUNTED SAVINGS (2F5 +3C) $5212.524

6. SAVINGS TO INVESTMENT RATIO (SIR) = (5/lE) = 23.18

7. SIMPLE PAYBACK PERIOD (ESTIMATED) (SPB) = (lE/4) = 1.22

Appendix I – Attachment 2 Page 2 of 4

SAMPLE FORMATLIFE-CYCLE COST ANALYSIS FOR ENERGY CONSERVATION INVESTMENT

1992MCA (AS OFLFA= 1.08

DATE 09 AUG 1991PROJECT NUMBERPROJECT. TITLE:INSTALLATION:LOCATION:

PROGRAM PROJECTS

38806 S REVISION DATE: 07 NOV 199111/22/1991 AT 07:41:48) 09 AUG 1991

FY 92 PROGRAM38806ECIP: Insulate Stream LinesCharles Melvin Price Spt CtrIllinois

SECTION 11- ECONOMIC ANALYSIS

11C CONSIDERATION OF ALTERNATIVES

Maintain Status QuoInsulate Steam Distribution System

11D ECONOMIC JUSTIFICATION SUMMARY

Life-Cycle Cost Analysis Data Base

1. Investment costs were calculated using R. S. Means estimating publications. Total investment costs,including contingency and SIOH= $224,896

2. Energy savings were calculated using various energy conservation publications.

a. Documents included:

(1) Architects & Engineers Guide to Energy Conservation in Existing Building, DOE, 1979

(2) ASHRAE Fundamentals, 1985

(3) The 1975 Energy Management Guidebook, published by editors of Power Magazine, McGraw HillInc, NY, NY, 1975

b. Distillate fuel oil will not be affected by the project. Initial firing of the boilers uses #2 fuel oil. Firingup procedures at the beginning of the heating season will not change.

Distillate fuel oil savings = O

c. Residual fuel oil (#6 fuel oil) is the primary fuel used in the central heating plant steam distributionsystem.

(1) Data base:

(a) Boiler data -- temperature at 100 psi = 170° C (338° F), 80 psi = 162° C (324° F)

(b) Assume average steam/condensate temperature in the line = 116° (240°) to 121° C (250° F)

(c) To be conservative, assume some of the lost heat from the pipes will find its way to theground level, due to both the large amount of heat lost and the circulation built up by both the temperaturegradient and the unit heater blowers. Assume 25 percent of the lost heat is returned to the floor level.


(2)

(3)

(4)

Current situation -- No insulation on steam or condensate line in warehouse 2. No insulation on thecondensate lines in warehouse 3. The steam line in warehouse 3 does have insulation installed.

(a) Heat loss calculations:

Q (bare) = T x L T = 7-month heating season = 5040 hourswhere Q (bare) = bare pipe seasonal heat loss L = unit length of pipeHL = unit heat loss

(b) Heat loss

Pipe Size BtuH/10’ 10’ Lengths (L) Q(MBtu/season)

1/2 in. 1125 226.8 1,285.956

3/4 in. 1350 154.0 1,047.816

1 1/2 in. 2300 226.8 2,629.066

2 1/2 in. 3250 913.7 14,966.406

4 in. 5160 446.4 11,609.257

6 in. 7360 12.0 445.133

Total Q (bare = HL x T x L= 31,983.634

Proposed Situation: Install 2 inches of insulation on all bare steam and condensate lines inwarehouse 2 and 3.

(a) Heat loss calculations:

Pipe Size BtuH/11 Length (LF) Q(MBtu/season)

1/2 in. 12 2268 137.169

3/4 in. 13 1340 100.901

1 1/2 in. 20 2268 228.614

2 1/2 in. 26 9137 1,197.312

4 in. 55 4464 1,237.421

6 in. 75 120 4 5 . 3 6 0

Total Q (insulated) = HL x T x L= 2,946.777

Residual fuel savings = Q (bare) - Q (insulated)

Q (lost) = 31,983.634 MBtu/yr - 2,946.777 MBtu/yr = 29,036.857 MBtu/yr

Not all heat lost from the pipes will be lost to the facility. Even though the warehouses have high bays, we canassume 20 percent of the heat is recycled through the buildings.

Therefore, Q (lost) = 29,037 MBtu/year x 0.75 = 21,777 MBtu/yr.

Considering boiler efficiency of 78 percent, this equates to a residual fuel input equal to21,777 MBtu/yr/0.78 = 27,919 MBtu/yr.

Appendix I — Attachment 2 Page 4 of 4

Category

1.

2.

3.

4.

5.

6.

ATTACHMENT 3

ENERGY CONSERVATION PROJECT TYPES(Recommended Economic Analysis Life)

Title

EMCS or HVACControls (10 years)

Steam and CondensateSystems (15 years)

Boiler Plant Modifications(20 years)

Heating, Ventilation, AirConditioning (HVAC)(20 years)

Weatherization(25 years)

Lighting Systems(15 years)

Description

Projects which centrally-controlenergy systems with the ability toautomatically adjust temperature,shed electrical loads, control motorspeeds, or adjust lighting intensities.

Projects to install condensate lines,cross connect lines, distributionsystem loops, repair or install insula-tion, and repair or install streamflow meters and controls.

Projects to upgrade or replace centralboilers or ancillary equipment toimprove overall plant efficiency; thisincludes fuel switching or dual fuelconversions.

Projects to install more energy-effi-cient heating, cooling, ventilation, orhot water heating equipment; thisincludes the HVAC distributionsystem (for example, ducts andp i p e s ) .

Projects improving the thermal enve-lope of a building; this includesbuilding insulation (wall, roof, foun-dation, doors), windows, vestibules,earth berms, and shading.

Projects to install replacement light-ing systems and controls; this wouldinclude day lighting, new fixtures,lamps, ballasts, photocells, motionsensors, IR sensors, light wells, andhighly reflective paint.


Category

7.

8.

9.

10.

ENERGY CONSERVATION PROJECT TYPES(Recommended Economic Analysis Life)

Title Description

Energy Recovery Projects to install heat systems exch-(20 years) angers, regenerators, or heat reclaim

units, or recapture energy lost to theenvironment.

Electrical Energy Systems Projects that will increase the energy(20 years) efficiency of an electrical device or

system or reduce costs by reducingpeak demand.

Solar Systems Any project utilizing renewable(10 years active) energy; this includes active solar(20 years passive and PV) heating, cooling, hot water, industri-

al process heat, photovoltaic (PV),wind, biomass, geothermal, andpassive solar applications.

Facility EnergyImprovements(20 years)

Appendix I — Attachment 3

Multiple-category projects or thosethat do not fall into any othercategory.

Page 2 of 2

Appendix J — Application of ASHRAE Equipment Room Design Requirements

Appendix J – Application of ASHRAE EquipmentRoom Design Requirements

ABSTRACT: This appendix discusses the mechanical equipment room design requirements forrefrigeration systems covered by ASHRAE 15-1994, “Refrigerant Quality Rule 4“. Specifically,this appendix discusses refrigeration system placement within the mechanical equipment room;ventilation requirements; doors, passageways and access; open flame devices; and pressure-reliefpiping.

J.1 Introduction

ETL 91-7 requires all new mechanicalrooms be designed to meet the require-ments of ASHRAE 15-1994. ETL 91-7also requires existing mechanical rooms tobe upgraded to comply with this standardwhen existing equipment is either retro-fitted or replaced. ASHRAE 15-1994defines a set of minimum requirements toensure the safety of personnel workingwithin equipment rooms. The standard alsodefines requirements that ensure theoperability and maintainability of equip-ment located in equipment rooms. Most ofthe equipment rooms located in Air Forcefacilities will be subjected to ASHRAE15-1994, “Refrigerant Quality Rule 4“ dueto the quantity and type of refrigerants en-countered in these facilities. This ruleapplies to all low-probability systems, inall occupancy classifications, using either aGroup Al or B1 refrigerant (see TableC-1, Physical Properties of Refrigerants,in Appendix C, Refrigerant Storage Rec-ommendations and Requirements). Othermechanical equipment room operational re-quirements, such as safety equipment andplacement of leak detection devices, arediscussed in more detail in Appendix B,

Refrigerant Sensors and Monitoring ofEquipment Rooms.

J.2 Refrigeration SystemPlacement

Placement of chillers in a mechanicalequipment room depends on various fac-tors, including:● access for service work,● proximity to other equipment in the

mechanical equipment room, and● air flow through the mechanical equip-

ment room for ventilation.Clearances should be considered as mini-mum requirements for normal operation,maintenance, service, and repair of equip-ment. ASHRAE 15-1994 calls for clearhead room of 7.25 feet below equipmentsituated over passageways. This require-ment is designed to prevent piping andequipment from being installed in a loca-tion which will constitute a physical hazardto people or equipment moving throughaisleways. While these clearances aregenerally the guiding factor for positioningthe chillers in the mechanical equipmentroom, attention must also be paid to airflow patterns resulting from interaction ofthe ventilation system and the equipment in

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the mechanical equipment room to avoidareas of stagnation.

J.2.1 Chiller PlacementChillers should be placed between theventilation inlet and outlet and should notcreate areas of air stagnation. Figure J-1,Multiple Chiller Equipment Room Layouts,shows both good and bad examples ofconfigurations for multiple chiller mechan-ical equipment rooms. Arrangement A inthe figure is an example of how chillersshould be placed, whereas Arrangement Bexemplifies an arrangement which wouldcreate stagnant areas between the chillers.

J.3 Ventilation VolumeRequirements

Mechanical equipment room volume re-quirements are covered in ASHRAE15-1994. This standard splits ventilationair requirements into Natural andMechanical ventilation based on locationof the equipment.

J.3.1 Natural VentilationASHRAE 15-1994 states:

When a refrigeration system is locatedoutdoors more than 20 feet from anybuilding opening and is enclosed by apenthouse, lean-to or other open struc-ture, natural ventilation may beemployed as an alternative to mechani-cal ventilation.

The outdoor structure must not be connect-ed to any occupied building by any meansto include doorways, pipe tunnels or elec-trical conduit raceways, ventilation, or

ductwork. Figure J-2, Remote MechanicalEquipment Room, shows an example of aremote mechanical equipment room.

J.3.1.1 ASHRAE 15-1994 also states:The free-aperture cross section forventilating the machinery roomshould amount to at least:

F = G0 . 5

Where:F = The free opening area in

square feet.G = the weight of refrigerant in

pounds in the largest sys-tem, any part of which islocated in the machin-ery room.

The location of the opening (or openings)shall consider the density of the refriger-ant. For example: if the refrigerant in useis heavier than air (that is, the specificgravity of the refrigerant is greater thanone) the opening(s) should be located at orclose to floor level. If the refrigerant islighter than air, the opening(s) should belocated close to the ceiling of the mechani-cal room for maximum ventilation effect.As an example, consider a chiller with an800 lb charge. The free opening area insquare feet would be calculated as follows:

F = 8000.5 = 28 ft2

Thus, a five-foot by six-foot openingwould slightly exceed this square footagerequirement.

J.3.2 Mechanical VentilationWhen mechanical rooms do not meet therequirements described above as a naturalventilation system, then mechanical

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Figure J-1. Multiple Chiller Equipment Room Layouts

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Appendix J – Application of ASHRAE Equipment Room Design Requirements

O f f i c e

O f f i c e

Refr igerat ionSystem

Lean-to or Other Structure withNatural Ventilation.

▲

More

Than

20

Feet▼

Figure J-2. Remote Mechanical Equipment Room

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Appendix J —Application of ASHRAE Equipment Room Design Requirements

ventilation must be provided. ASHRAE15-1994 states the following with respectto mechanical ventilation:

. . . The minimum mechanical ventila-tion required to exhaust a potentialaccumulation of refrigerant due toleaks or a rupture of the system shallbe capable of removing air from themachinery room in the following quan -tity:

Q =Where:

Q =

G =

100 x G0.5

the air flow in cubic feet perminute in purge modethe weight of refrigerant inpounds in the largest sys-tem, any part of which islocated in the machin-ery room.

Using the same example charge of 800 lb,the air flow in cubic feet per minute wouldbe calculated as follows:

Q = 100 x 800°5 = 2800 CFM“Q” represents the minimum air flow theventilation system must provide to purgethe mechanical equipment room of refrig-erant vapors. According to ASHRAE15-1994, it is not necessary to continuous-ly run the ventilation at this volume,provided:a)

b)

c)

Ventilation is provided when occupiedat least at 0.5 cfm per square foot ofmachinery room area or 20 cfm perperson; and,Operable, if necessary for operatorcomfort, at a volume required to main-tain a maximum temperature rise of-80 C (180 F) based on all of the heat-producing machinery in the room.Mechanical room ventilation must alsobe designed to remove sensible heat

loads generated by the equipmentlocated in the room. This flow rateshould be designed to maintain thetemperature in the room no higher than-80 C (180 F) higher than the outdoorambient temperature. Note that mostelectrical devices (motors, switchgear,for example) are designed to operate inan environment where the ambient tem-perature does not exceed 40° C(104° F). This requirement must bemet whether or not the equipmentroom is occupied and may impose therequirement for higher ventilation flowrates than those required for dilutionventilation of refrigerant gases.

J.3.2.1 Two distinct ventilation rates aredefined for the mechanical equipmentroom: (1) normal ventilation at a rate of0.5 cfm per square foot (or more, if exces-sive heat is produced in the room), and isrequired any time the mechanical equip-ment room is occupied and (2) the purgeventilation rate, based on the weight ofrefrigerant in the refrigeration system.

J.3.2.2 If the mechanical equipment roomis occupied, the ventilation system must beoperated to provide the normal ventilationrate. This can be accomplished by runningthe fan continuously, starting it automati-cally by a motion detector, or by providinga fan switch near the mechanical equip-ment room entrance(s). If a switch isprovided, a sign or other prompt should beused to indicate the requirement for venti-lation during occupancy. A simple methodof assuring operation of the purge ventila-tion system would be to interlock theventilation system with the room lighting.

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J.3.2.3 The purge ventilation rate isrequired whenever there is a build-up ofrefrigerant in the mechanical equipmentroom, as indicated by the refrigerant vapormonitor. Ventilation at purge volume mustbe automatically initiated by the monitor’salarm contacts. A switch for manual initia-tion is also suggested and should be locat-ed outside the main entrance to the me-chanical equipment room.

J.3.2.4 A single ventilation system can bedesigned to serve both purge ventilationand normal ventilation requirements. If thenormal ventilation flow rate requirementsare higher than the purge ventilation flowrate requirements, no additional purgerequirement is needed since the ventilationsystem will operate constantly when theroom is occupied. If the purge ventilationflow rate is higher than the normal ventila-tion flow rate, two-speed fan motors,variable-speed fan motors, or additionalexhaust fans can be employed to increasethe flow rate from the normal ventilationflow rate to the purge ventilation flow ratewhen the mechanical room is occupied.Again, the initiation of this higher flowrate can be accomplished by the use ofmotion detectors or interlocks with arealighting circuits.

J.4 Location of Vents

Locations for the ventilation system’s inletand discharge must be properly positionedto provide efficient ventilation of themechanical equipment room. ASHRAE15-1994 generally addresses this require-ment as follows:

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. . . The discharge of air shall be tothe outdoors in such a manner as not tocause inconvenience or danger. Open-ing for supply air shall be positioned toavoid intake of exhaust air. Provisionshall be made for supply air to replacethat being exhausted. Air supply andexhaust ducts to the machinery roomshall serve no other area.

J.4.1 Separate Ventilation SystemThe equipment room ventilation systemmust be separate from the systems thatprovide ventilation to other parts of thebuilding. The fans and ductwork used toventilate the equipment room must notsupply any other part of the building, andthe discharge must not interfere with anyfresh air intakes. Because some of the fansmay not run continuously, it is importantto locate the discharge of each fan where itwill not be inadvertently blocked while thefan is off. Make-up or outside air must beproperly conditioned to avoid damage fromlarge, rapid temperature swings or freezingtemperatures.

J.4.2 Exhaust Fan Provides PurgingThe exhaust fan must provide purging ofrefrigerant from the equipment room. Toremove refrigerants, which are heavierthan air, the exhaust fan inlet should belocated near the equipment (if possible)and close to the floor, rather than at ceil-ing height. Refrigerants released into anequipment room tend to drop to the floorand fill the room from the bottom, unlessdisturbed by air turbulence. Maximumprotection for equipment room occupantsis provided when the intake of the exhaust


fan is located below the normal breathingzone as shown in Figure J-3. SuggestedExhaust Fan Location. It is important thatthe ventilation provide for an “air sweep”across all refrigeration equipment.

J.4.2.1 When exhaust fans are used tokeep the equipment room cool or removesmoke from accidental fire, they are typi-cally installed in the ceiling because heatand smoke both rise. However, if theventilation system is used to exhaust re-frigerants and remove heat or combustionproducts from the mechanical equipmentroom, provisions must be made for inletsat both floor and ceiling levels. This canbe accomplished using either separate fansor a ducted fan with inlets at the floor andceiling, as shown in Figure J-4, Dual DuctExhaust.

J.4.2.2 The total ventilation volume re-quired during refrigerant purging couldcome from the sum of both the ceiling andfloor-level fans. However, to provide themost effective purge of refrigerant, thefloor-level fan should be capable of meet-ing the calculated refrigerant purge rate. Aducted system can be used with or withoutflow control dampers. If dampers areused, they should be designed and con-trolled to provide maximum exhaust fromthe floor-level inlet when a refrigerantalarm condition is detected. The inlet tothe fan should be located near the potentialleak source and away from the fresh airintake. This arrangement will produce asweeping action that draws fresh air acrossthe leak source on its way to the exhaustfan.

J.4.2.3 Figure J-5, Modifying an ExistingVentilation System, is a sketch of a me-chanical equipment room located in thecomer of a building. In Arrangement A,ventilation is provided via six louveredservice doors along one wall (fresh airinlet) and an exhaust fan mounted four feetabove the floor in an adjacent wall. Con-tinuous ventilation is provided at the re-frigerant purge volume. While this ar-rangement provides adequate air movementpast the chiller, it also creates a stagnantarea in one comer of the room. Ductingthe exhaust fan inlet across the oppositewall, as depicted by Arrangement B,would provide better air flow across theentire

J . 5

room.

Mechanical EquipmentRoom Doors, Passagewaysand Access

ASHRAE 15-1994 requires that:Each refrigerating machineryshall have a tight fitting door

roomor doors

opening outward, self closing if theyopen into the building, and adequate innumber to ensure freedom for personsto escape in an emergency. There shallbe no openings, other than doors, thatwill permit passage of escaping refrig-erant to other parts of the building.

Note that the louvered doors shown inFigure J-5 were used to provide the neces-sary service clearance for the chillers, andalso to provide a direct exit to the out-doors. Access to the machinery room isspecifically y restricted to authorized person-nel by ASHRAE 15-1994.

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Figure J-3. Suggested Exhaust Fan Location

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Figure J-4. Dual Duct Exhaust

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A r r a n g e m e n t A

Air

Inlet Via

3 Pairs

o f

Louvered Doors

Air

Inlet Via

3 Pairs

o f

Louvered Doors

Figure J-5. Modifying An Existing Ventilation System

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J. 6 Open Flame Devices

Where a mechanical equipment room con-tains a flame-producing device, as well asa refrigeration system, compliance withASHRAE 15-1994 recommends:

●

●

●

Ducting combustion air to the boilerfrom outside the equipment room toprevent air and refrigerants present inthe equipment room from entering theboiler.Erecting a partition wall which willphysically isolate the flame-producingdevice from the refrigerant-containingequipment, should space and egresspath constraints permit.Using the refrigerant sensor to shutdown the flame producing deviceshould the equipment room concentra-tion of refrigerant vapor exceed therefrigerant’s Allowable Exposure Limit(AEL).

J. 7 Pressure-Relief Piping

ASHRAE 15-1994 contains these generalrequirements for pressure-relief

Every refrigeration system shall beprotected by a pressure-relief device orsome other means designed to safelyrelieve pressure due to fire or otherabnormal conditions.

ASHRAE 15-1994 also includes veryspecific descriptions for determining whenpressure-relief devices are necessary andhow to size them. The original equipmentmanufacturer generally provides suchdevices on packaged systems, as well ason the major components of systems thatare built-up in the field. However,ASHRAE 15-1994 should be reviewed in

all cases to ensure compliance with thestandard.

J.7. 1 Piping Rupture DevicesOnce the equipment is installed, each ofthe rupture devices must be piped to a safelocation in accordance with the followingguidelines from ASHRAE 15-1994:

Pressure-relief devices and fusibleplugs on any system containing aGroup A3 or B2 refrigerant, and onany system containing more than110 lb of a Group Al refrigerant shalldischarge to the atmosphere at a loca-tion not less than 15 feet above theadjoining ground level and not lessthan 20 feet from any window, ventila-tion opening, or exit in any building. Alist of A3 and B2 refrigerants can befound in Appendix B of this document.The discharge termination shall befashioned in such a manner to preventdirect spray of discharged refrigeranton personnel in the vicinity and foreignmaterial or debris from entering thedischarge piping. Discharge pipingconnected to the discharge side of afusible plug or rupture member shallhave provisions to prevent plugging thepipe in the event the fusible plug orrupture member functions.

J.7.1.1 It is critical that the materialsused in the pipe and joints of the reliefdevice piping are compatible with therefrigerant that will be vented. Commonlyused and acceptable materials include steelor copper pipe. Use of PVC piping is notrecommended. Many adhesives employedin this type of piping construction have notbeen tested for refrigerant compatibility.Flexible connection devices used for vibra-

J-11


tion isolation must also be compatible withthe vented refrigerant. A flexible stainlesssteel pump connector (or its equivalent) isrecommended.

J.7.1.2 Vent pipes should also beequipped with a drip leg capable of hold-ing up to one gallon of liquid. Provide astandard 1/4” FL x 1/4” NPT cappedrefrigerant service valve to facilitate liquidremoval. Accumulated liquid should beremoved from the drip leg on a regularmaintenance schedule, at least once everysix months. Use appropriate refrigerant oilhandling procedures when draining thevent since refrigerant oil may be dis-charged in the exhaust from the purgeunit. This oil may, over time, accumulatein the drip leg. An example of a correctlypiped vent pipe is shown in Figure J-6,Suggested Refrigerant Vent Piping.NOTE: 1 gallon = 231 cubic inches. Thefollowing equation should be used to findthe length “L,” in inches, of pipe requiredfor the drip leg:

L = 294/d2

Where:d = the inside diameter, in inches,

of the pipe.

J.8 Purge Discharge

Purge units used to remove noncondens-able gas from the refrigeration systemshould have discharge lines piped accord-ing to the requirements for relief piping.Generally, the most convenient way toproperly exhaust the purge discharge to theatmosphere is to route it into the valve(rupture disc) vent pipe, The purgedischarge line must not contain any liquidtraps and should be sloped away from the

purge unit to prevent liquid from collectingat the purge unit. Additionally, care shouldbe taken to ensure that no liquid from thepurge discharge can collect at the pressure-relief valve or rupture disc. Connect thepurge discharge pipe on the chiller side ofany vibration isolation as shown inFigure J-6. Consult the manufacturer ofthe purge equipment for proper sizing ofthe purge discharge line.

J.8.1 Minimize LossPurge-related refrigerant loss should bekept as low as possible to minimize refrig-erant discharge to the atmosphere andavoid the expense of replacing lost refrig-erant. To minimize purge-related refriger-ant loss:● Choose a purge unit with a low refrig-

erant-to-noncondensable-gas dischargeratio that can operate while the chilleris off. The Environmental ProtectionAgency (EPA) has not established adefinition of “high efficiency” as itapplies to purge units. However, sever-al units are now commercially availablewhich are capable of achieving 0.0005pounds of refrigerant discharged perpound of air purged. See Appendix E,Equipment to Reduce Refrigerant Re-lease During Maintenance and Opera-tion of Air Conditioning and Refrigera-tion Systems, for a more detailed dis-cussion of purge systems.

● Routinely monitor the refrigerationsystem for leaks and properly repairany that are found. Routine logging ofpurge operation and chiller run-timeprovides an excellent indicator ofsystem integrity.

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Figure J-6. Suggested Refrigerant Vent PipingJ-13


J. 9 Occupied Space Contamina- room containing refrigeration equipment to

t ion be sealed and gasketed. This will preventthe possible spread of refrigerant vapor to

ASHRAE 15-1994 requires all access the occupied space of the building in casepanels in ductwork or air handling equip- of a catastrophic refrigerant loss.ment located in a mechanical equipment

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Appendix K — AC/R Energy Conservation Devices


ABSTRACT: The Air Force objective is cost reduction through energy conservation andimproved energy efficiency whenever possible. This appendix explores energy conservationdevices, and their application to both new and existing air conditioning and refrigeration (AC/R)systems.

K.1 Introduction

The phase-out of ozone-depleting com-pounds (ODC) will result in the systematicreplacement of existing refrigerationequipment. The replacements will be eithernew equipment using alternative refriger-ants or the retrofit of existing equipment toallow the use of alternative refrigerants.During this period of replacement andretrofit, numerous opportunities will ariseto specify and install devices to enhancethe energy efficiency of these new andretrofitted units. This appendix describesseveral devices which may be consideredfor installation and explains how theyaffect the performance of refrigerantsystems.

K.2 Conservation Devices

The following is a list of refrigerationaccessories that should be considered whenretrofitting or replacing an existing airconditioning (A/C) system. These itemshave been proven to increase, to someextent, the efficiency of a typical refrigera-tion cycle. The original equipment manu-facturer (OEM) should be contacted whenconsidering each of these devices:● desuperheaters,● liquid-suction heat exchangers,

● variable speed motor drives,● liquid subcoolers,● plate and frame heat exchangers, and● liquid pressure amplification.

K.2.1 DesuperheatersThe primary function of a desuperheater(sometimes referred to as a gas inter-cooler) is to recover waste heat normallyrejected by the A/C equipment and use itto heat domestic or process water.

K.2.1.1 The energy savings are signifi-cant. A typical 40-ton, air-cooled systemcan heat 192 gallons of water per hour. Ifthe 40-ton load is continuous and theelectrical rate is five cents per kWh, adesuperheater can save $37 per day, or$4,400 over 120 days of operation.

K.2.1.2 Desuperheaters are most com-monly used in direct expansion systemsthat range in size from 10 to 100 tons.They can be used on a variety of equip-ment such as: rooftop units, split systems,self-contained units, and air-cooled con-densing units.

K.2.1.3 A desuperheater is simply a heatexchanger designed to transfer heat fromthe superheated refrigerant vapor down-stream of the compressor to a water

K-1


stream. This heated water can be used fordomestic hot water or for space or processheating.

K.2.1.4 Some special considerations existin the application of desuperheaters. Localplumbing codes may require double-walledheat exchangers or a secondary heat ex-changer. They ensure a leak between therefrigerant and water side of the heatexchanger does not result in the contamin-ation of the potable water supply. Localplumbing codes should be consulted todetermine local requirements. Additional-ly, the physical location of the desuper-heater and the water pipelines may bevulnerable to freezes. Heat tracing andpipe insulation may be necessary to pre-vent potential freeze damage.

K.2.1.5 Circulating distribution is used inapplications that have a varying demandfor hot water or a need for extra hot wa-ter. After being heated by the desuper-heater, the water flows into a water stor-age tank. As long as the compressor is inoperation, a pump continuously circulateswater from the storage tank through thedesuperheater, raising the water tempera-ture with each pass.

K.2.1.6 Preheat distribution is used inapplications with continuous compressoroperation and a constant demand for hotwater. Water flows directly from thedesuperheater into the building’s waterheater.

K.2.1.7 The desuperheater is installed byplacing it directly into the equipment’srefrigerant piping system (in the hot gasline between the compressor and

condenser). A minor adaptation to the hotwater system is required, as well as a tapinto the compressor discharge line. De-pending on the application, the addition ofa pump and water storage tank may alsobe required. Contact the OEM for moredetailed information on desuperheaters fora specific application.

K.2.2 Liquid-Suction Heat ExchangersGenerally, liquid-suction heat exchangerssubcool the liquid refrigerant and super-heat the suction gas. They are used for oneor more functions.

K.2.2.1 The efficiency of the thermody-namic cycle for certain halocarbon refrig-erants can be increased when the suctiongas is superheated by removing heat fromthe liquid. This increased efficiency mustbe evaluated against the effect of pressuredrop through the suction side of the ex-changer, forcing the compressor to operateat a lower suction pressure. Liquid-suctionheat exchangers are most beneficial at low-suction temperatures. The increase in cycleefficiency for systems operating in the air-conditioning range (down to about 10 C(30° F) evaporating temperature) usuallydoes not justify their use.

K.2.2.2 To subcool the liquid refrigerantto prevent flash gas at the expansion valve,the heat exchanger should be located nearthe condenser or receiver to achieve sub-cooling before pressure drop occurs.

K.2.2.3 In certain applications, smallamounts of liquid refrigerant will returnfrom the evaporator to the compressor. Inthese situations, a suction-line accumulatorand liquid-suction heat exchanger

K-2


arrangement can be installed to trap liquidfloodbacks and slowly vaporize them. Heatpumps are susceptible to trapping liquidrefrigerant in the compressor suction linesduring the reversal of the refrigerant cycle.Additionally, if the design of an evaporatormakes a deliberate slight overfeed of re-frigerant necessary either to improve evap-orator performance or to return oil out ofthe evaporator, a liquid-suction heat ex-changer is needed to evaporate the refrig-erant. This overfeed is controlled by ad-justing thermostatic expansion values forminimal superheating of the refrigerantleaving the evaporator.

K.2.3 Variable Speed Motor DrivesVariable frequency motor drives operateby converting normal 60 Hz alternatingelectrical energy into direct current and,then, inverting the electricity back to analternating wave form of variable frequen-cy. This variable frequency electricaloutput allows the speed of a standardinduction motor to vary with the change inthe frequency of the output. Thus, energy-consuming devices such as pumps and fanscan be easily converted to operate within arange of speeds, therefore, matching per-formance capabilities to dynamic operatingconditions rather than at a single designpoint. The speed of centrifugal pumps andfans is directly proportional to the cube ofthe power input. A reduction to 50 percentof full speed equates to a correspondingreduction of input power to 12.5 percentof full-speed requirements.

K.2.3.1 Conventional, fixed-speed pumpsand fans are “throttled” by control valves,dampers, or inlet-guide vanes. Whencentrifugal pumps, fans, and chillers

service a wide range of flow rates, theyoperate much more efficiently when drivenby variable speed drives at reduced flowconditions. The savings can be significantin applications such as hot water supplysystems, chilled water supply systems, andvariable air volume (VAV) distributionsystems.

K.2.3.2 An additional benefit of a vari-able speed drive is to “soft start” largemechanical equipment. By starting motorsat reduced speed, gradually increasingmotor speeds to full operating condition,the dynamic torque induced in mechanicalcomponents during startup is reducedsignificantly.

K.2.4 Liquid SubcoolersSubcooling is a term used to describe thecooling of a liquid refrigerant, at constantpressure, to a point below the temperatureat which it was condensed. When a liquidrefrigerant can be subcooled, either bycold water or by some other means exter-nal to the refrigeration cycle, the refriger-ating effect of the system will beincreased. The subcooler can be a coil or aloop of tubing immersed in a spray tank. Itcan also be additional surface on the airintake side of the condensing coil. The useof a desuperheater may result in subcool-ing of liquid refrigerant by allowing aportion of the condenser to function as asubcooler.

K.2.4.1 The effect of subcooling is illus-trated in Figure K-1, Pressure-EnthalpyChart. Refrigerant vapor is condensed at atemperature of 38° C (100° F), and pointB represents subcooled liquid at 24° C(76° F). Liquid throttled from A to the

K-3


Figure K-1. Pressure-Enthalpy Chart

K-4


evaporator pressure will be at condition D,while C represents liquid throttled frompoint B. The refrigerant leaves the evapo-rator as saturated vapor at point E. Theadditional distance between C and D repre-sents gained refrigeration capacity. Thegain for this particular example can beshown to be over 11 percent of the origi-nal refrigeration effect. As a general rule,a one percent gain in system capacity canbe anticipated for each -17° C (2° F) ofliquid subcooling obtained from outside therefrigeration cycle.

K.2.5 Plate and Frame HeatExchangers

A plate and frame heat exchanger consistsof a number of pattern-embossed, gasketedchannel plates held together in a frame.Every other channel plate is turned 180degrees so the herringbone pattern givesrise to a lattice of contact points serving assupports for a complex system of channels.Gaskets are placed in grooves around theouter edge of the plate and around two ofthe punched holes in the comers of theplate. The plate spaces are screened offboth from the atmosphere and from theadjacent spaces, enabling two differentmedia to flow in two separate systems ofchannels in true countercurrent operation,completely separated from each other.

K.2.5.1 Fixed-surface plate and frameexchangers have no moving parts. Alter-nate layers of plates, separated and sealed(referred to as the heat exchanger core),form the heat-rejecting and heat-receivingfluid passages. Flat-plate heat exchangers(sometimes referred to as “plate andframe”) are considered to be the mostefficient type of heat exchangers. The

typical engineered performance allows theleaving temperature of the heated fluidstream to be within -17° C (1° F) of theentering temperature of the heat-rejectingfluid stream.

K.2.5.2 Simplicity and no moving partsadd to the reliability, longevity, minimumpressure loss, and safe performance ofthese exchangers. The heat exchanger isdesigned to be easily dismantled and reas-sembled. For high-fouling media, the heatexchanger plates can easily be disassem-bled for cleaning to remove fouling whichwould inhibit heat transfer.

K.2.5.3 The number of plates in the heatexchanger can also be changed to enable itto work under different operating condi-tions. Plate and frame heat exchangers canbe manufactured with channel plates ofacid-resistant stainless steel or less reactivematerials such as titanium and hastelloy.Standard gasket materials include Nitrileand EPDM, but other materials such asViton can also be supplied. Frames areproduced in mild steel and stainless steelversions.

K.2.5.4 Today, industry recognizes theplate and frame heat exchanger as the mostefficient type of heat transfer equipmentavailable. No other type of heat exchangerdelivers the high thermal efficiency, easymaintenance, reduced fouling, low cost,and close approach temperature.

K.2.5.5 Plate and frame heat exchangersare often used for cooling tower isolation.For instance, hydronic heat pump systems(see Figure K-2, Hydronic Heat Pump withOpen Cooling Tower) may use open circuit

K-5


Figure K-2. Hydronic Heat Pump with Open Cooling Tower

K-6


cooling towers to reject heat when in thecooling mode. The size of their fluidpassages make the individual water-sideheat exchangers in the heat pumps subjectto fouling by leaves, grass cuttings, andsimilar debris; the fouling can becontrolled with minimal loss of thermalefficiency by using a plate and frame heatexchanger to isolate the water from thecooling tower side.

K.2.5.6 Plate and frame heat exchangerscan also be used to allow an evaporativecooling tower to serve as a cooling source.Figure K-3, Free Cooling (Water-SideEconomizer) - Temperature Change, andFigure K-4, Free Cooling (Water-SideEconomizer) - Flow Rate, schematicallyrepresent two configurations of a chillerbypass system using condenser water tocool the chilled water stream by transfer-ring heat using a flat-plate heat exchanger.To accomplish this, the chiller is bypassedand shut down, conserving significantenergy and the cooling tower controls arereset to allow condenser water to be sup-plied at a lower temperature.

K.2.5.7 The evaporative cooling process,accomplished by a cooling tower, is limit-ed by the wet bulb temperature of theambient air. Theoretically, the condenserwater can be cooled to equal the wet bulbtemperature of the ambient air. As a prac-tical matter, most evaporative coolingtowers are only designed to cool the con-denser water to within -15° C (5° F) to-14° C (6° F) of the ambient wet bulbtemperature. Therefore, this type of ar-rangement has the capability to supplychilled water for space or process coolingload at a temperature from -14° C (6° F)

to -13° C (8° F) above ambient wet bulbtemperature using a plate and frame heatexchanger selected for a -17° C (1° F) to-17° C (2° F) approach. Figure K-3 repre-sents a configuration with full chilledwater flow at an elevated chilled watersupply temperature. Figure K-4 representsthe same system reset to supply chilledwater at normal temperature at a reducedflow rate. Either of these configurationsare feasible. The ability to use this type ofsystem is only limited by the availability ofsuitable ambient wet bulb conditions, coin-cident with the need for chilled water.

K.2.5.8 Plate and frame heat exchangersare also used in thermal storage systems.This configuration, shown in Figure K-5,Thermal Storage, uses a plate and frameheat exchanger to isolate a circulatedchilled water loop from a closed waterloop circulating through cold water storagebanks and a water chiller. The chillercontrols have been set to produce a leavingwater temperature of 3° C (38° F). This3° C (38° F) water is stored in a waterstorage tank which, in effect, acts as a“thermal capacitor. ” When demand forcooling is low, the chiller can continue tooperate to cool this large mass of water.Eventually, both of the cool water storagetanks will be cooled to 3° C (38° F).When the cooling load rises, the 3° C(38° F) chilled water from the first tankwill be supplied to the plate and frameheat exchanger where it will gain heatfrom the chilled water loop. It will beheated to a leaving temperature of 9° C(48° F), resulting in the cooling of thechilled water from 17° C (62° F) to 6° C(42° F). The 9° C (48° F) water leavingthe heat exchanger will blend with the cold

K-7


Plate Heat ExchangerCooling Tower Isolation

Figure K-3. Free Cooling (Water-Side Economizer) - Temperature Change

K-8


Plate Heat ExchangerCooling Tower Isolation

Figure K-4. Free Cooling (Water-Side Economizer) - Flow Rate

K-9


Figure K-5. Thermal Storage

K-10


water stored in the second cold waterstorage tank. The blended water from thesecond tank is recirculated to the chillerwhere it is again cooled to 3° C (38° F)before returning to the first cold waterstorage tank.

K.2.5.9 A thermal storage system like theone shown in Figure K-5 does not actuallyconserve energy. In fact, this type ofsystem will actually consume more energythan a simple closed chilled water loopdirectly connected to a chiller. This is dueto a loss in chiller efficiency resultingfrom the production of chilled water at alower (3° C (38° F) versus 6° C (42° F)in this case) temperature water. Systemslike this can, however, save energy dollarsby cooling the thermal mass during off-rate peak-time periods. In many locations,local utility companies will charge signifi-cantly lower rates for electricity duringoff-peak hours. If the rate structure at agiven base is structured in this way, suffi-cient energy dollars may be saved to makethis a financially-attractive alternative.

K.2.5.10 Electrical utility companies havedevised these off-peak rate structures toencourage consumers to use energy attimes when the demand is low. Electricityproduced to meet peak demands is oftengenerated using natural gas-fired turbines.They are more expensive to operate thannormal baseline sources (such as hydro-electric, nuclear, coal-fired).

K.2.5.11 Plate and frame heat exchangerscan also be used as shown in Figure K-6,Condenser Water Heat Recovery, to recov-er waste heat energy from the discharge ofa chiller cooling water stream. This

scenario allows this waste heat energy tobe recovered rather than be rejected at thecooling tower. Schemes like this are par-ticularly viable in situations where largevolumes of hot water are used, such ashospitals, cafeterias, and laundries.

K.2.6 Liquid Pressure AmplificationA significant amount of energy may bewasted if vapor is delivered to the expan-sion valve due to pressure losses in theliquid line from the condenser (for exam-ple, through hand valves, elbows, branchtees, and the pipe itself). Flash gas occurswhen an undesirable mix of liquid and gasis triggered by these pressure losses. Theeffect of flash gas in a refrigeration systemwill reduce the cooling efficiency of thecoil. Gas will occupy space within the pipethat would otherwise be occupied by theliquid.

K.2.6.1 In the past, this problem wasavoided by raising the pressure of therefrigerant entering the liquid line. Thiswas accomplished by increasing and main-taining a high pressure in the condenser.To do this, more energy input is requiredat the compressor and the overall cycleefficiency is lowered. A method has beendesigned to reduce power consumption andalso provide a method of reducing theamount of “flash gas” in the liquid line byovercoming the pressure losses within therefrigeration system.

K.2.6.2 Liquid pressure amplificationreduces “flash gas” in the liquid line bythe installation of a small centrifugal pumpin the liquid refrigerant line. The pumpincreases pressure to compensate for thesepressure losses with very little power

K-11

Appendix K — AC/R Enemy Conservation Devices

Figure K-6. Condenser Water Heat Recovery

K-12


consumption. When compared to elevating particularly applicable to direct expansionthe discharge pressure of the compressor, systems where the liquid receiver is locat-this can cut energy costs up to 40 percent, ed at extreme distances from the evapora-thus increasing the system’s working ca- tor or when the liquid refrigerant line ispacity. This type of system modification is subjected to unusually high temperatures.

K-13 (K-14 Blank)


Appendix L — Fundamentals of Cooling Load and Energy Analysis

Appendix L — Fundamentals of Cooling Loadand Energy Analysis

ABSTRACT: This appendix outlines the process for analyzing a building’s cooling loadrequirements and annual energy usage. An accurate and comprehensive cooling load and annualenergy usage profile is the basis for a properly-sized and -selected chilled water system.

L.1 Introduction

Energy conservation measures and buildingfunction changes since the design of theexisting cooling system may have changedthe maximum required cooling load for theair conditioning equipment. Over the nextfive years, additional conservation mea-sures may effect more changes. Thesechanges must be kept in mind when target-ing air-conditioning equipment for replace-ment or retrofit. The size of the equipmentshould be analyzed to correctly meet thedemand of today and the future. Load andenergy analyses are necessary for buildingsthat have undergone a significant changesince the chiller serving the building wasinstalled. If the building function has notchanged, but the chiller is never fullyloaded or is overloaded a substantialamount of the time, an analysis is neededto accurately size and economically selecta new chiller. By performing a detailedcooling load and energy analysis, a clearunderstanding of the building’s coolingneeds can be determined. Accurate loadmatching of the chiller(s) will reduceinitial capital cost and annual energyusage.

L.1.1 Building SurveyTo properly analyze a building and deter-mine its cooling load, a physical survey ofthe building is required. It is necessary toknow:● building material,● type and quantity of heat-generating

equipment,● occupancy,● orientation,● air handling system types, and● zoning.This information is determined by bothreviewing construction drawings and phys-ically surveying the building.

L.1.2 Cooling Load CalculationTo determine the maximum cooling capac-ity required from the chiller, a buildingpeak cooling load calculation must beperformed. This type of analysis can beperformed by following the guidelines .in the ASHRAE Handbook -1993, Chap-ter 26. Cooling load and energy analysiscalculations range from the simple to com-plex.

L.1.3 Energy AnalysisAn energy analysis determines the annualenergy consumption, usually on an hourly

L-1


basis. System part-load requirements canbe summarized in a cooling load profile.These data are used to determine the bestavailable alternative for cooling. The threeelements that, together, define the annualenergy usage are:1)

2)

3)

Space load - energy required to main-tain thermal comfort in the space.Equipment load - energy required bythe equipment that distributes the heat-ing or cooling medium to the con-ditioned space (for example, air han-dling units, pumps, fans).Plant load - energy required by thecentral plant equipment that convertsfuel or electricity to cooling effects(for example, chillers and coolingtowers).

L.1.3.1 A cooling load profile providesinformation allowing optimization of thechiller selection. The profile will identifythe amount of time the chiller is at 100percent (peak), 75 percent, 50 percent, and25 percent of full load. These values,along with energy cost data, are used toestimate the annual energy cost for thesystem. Because part-load efficiency variesbetween chiller types, these values shouldbe used when selecting a chiller. Matchingchiller characteristics to the load profileincreases overall system efficiency.

L.1.4 ProcedureThe following sections outline the basicsteps to determine the design load andannual cooling load profile for a givenbuilding. This analysis determines:● required capacity of the chiller(s),● total annual energy usage, and● the number of hours at part-load condi-

tions, defined as 100 percent (peak),

75 percent, 50 percent, and 25 percentof peak load.

L.2 Conduct Building Survey

Before conducting the survey, obtainconstruction drawings of the building.While performing the physical survey, talkto the building occupants and a buildingmanager or maintenance technician toobtain information not shown on the draw-ings. A building cooling load survey in-cludes the activities listed and discussedbelow.

L.2.1 Indoor and Outdoor ConditionsRecord the desired temperature and humid-ity for all spaces. These values may appearon the construction drawings, but theyshould be verified before proceeding.

L.2.2 Wall, Roof, Glass, andPartition Data

Record the construction, dimensions, andorientation. Shaded or glazed glass mayhave been added and should be noted.Much of this information can be found onthe drawings, but a spot check should beperformed to verify the information.

L.2.3 OccupancyRecord the number of people who occupyeach space and the activity level theymaintain. Determine the schedule of occu-pants, as it can impact the cooling load.

L.2.4 LightingRecord the number of fixtures, type,watts/fixture, and the usage schedule, ifapplicable. Determine if fluorescent light-ing system lamps or ballasts may havebeen upgraded from the original

L-2


installation. Lower wattage lamps or newT-8 style lamps may have been installed.Remember that wattage ratings on T-8lamps do not correlate with actual inputpower. For example, a four, 32-watt T-8lamp fixture with ballast draws approxi-mately 110 watts of power.

L.2.5 Other Internal Heat SourcesThese sources include computers, moni-tors, photocopying machines, coffee mak-ers, refrigerators, vending machines, andcooking equipment, among others. Recordthe number, type, and heat dissipated tothe space. Consider both sensible andlatent heat. This information can be deter-mined from amp-meter readings or esti-mated from nameplate data. Use cautionwhen taking nameplate data. These valuesare peak current requirements and may notrepresent steady-state current draw.

L.2.6 VentilationMeasure and record the rate of the outsideair entering the building through the airhandling systems. Design values will prob-ably be shown on the drawings, but ifpossible, the value(s) should be field veri-fied. The ventilation quantity should con-form to ASHRAE 62-1989 and any localrequirements.

L.2.7 InfiltrationIt is practically impossible to record infil-tration rates; however, they can be esti-mated by surveying for inleakage andbuilding pressure differences. A reviewand understanding of ASHRAE methodsfor estimating infiltration will allow anengineer to accurately survey an existingbuilding.

L.2.8 System OperationalCharacteristics

Determine if:●

●

●

●

chiller(s) is(are) shutdown during thewinter months and the shutdown peri-od,air handling systems use air-side econ-omizers,air handling systems use night setbackor shutdown, andchiller(s) is(are) integrated with anoperation schedule for duty cycling.

L.3 Conduct Cooling LoadCalculation

The method used to determine the coolingload is detailed in ASHRAE Handbook -1993, Chapter 26. The cooling load can becalculated manually for small buildings.Calculating the peak cooling load may alsobe estimated by taking measurements atthe appropriate time on an existing system(see section L.3.3). A computer programshould be used for large buildings.

L.3.1 Computer SoftwareDeveloping load calculations for buildingsof moderate or greater complexity canbecome laborious. Using a computer pro-gram can be of great benefit. In additionto saving time, computer programs forlarge building analyses provide the addi-tional calculations that would be impracti-cal to perform manually. For example, thecooling load may be calculated for eachhour of the design day so a load profilemay be plotted for that particular day.Some energy calculations are simply anextension of the load calculation. Theloads are calculated for each hour of eachday of the year (or some representative

L-3


sample) and building cooling loads areaccumulated over an annual period.

L.3.1.1 A list of companies offeringcooling load analysis software follow. Anycomputer programs used to conduct cool-ing calculations should use any of theASHRAE methods.

Elite Software Development, Inc.P.O. Drawer 1194Bryan, TX 77806(409) 846-2340

Carrier Air Conditioning CompanySyracuse, NY(315) 432-6000

The Trane CompanyCommercial Systems Group3600 Pammel Creek RoadLa Crosse, WI 54601-7599(608) 787-2000

Simulation Research Group 90-3147Lawrence Berkeley LaboratoryUniversity of CaliforniaBerkeley, CA 94720(510) 486-5711

L.3.2 Simplified Cooling LoadCalculation

The building maximum cooling load calcu-lation is presented in a simplified mannerin Figure L-1, Cooling Load Calculation.(Details of each equation are published inASHRAE reference material directed atthe novice as well as the experiencedengineer.)

L.3.3 Measure/Validate MaximumCooling Load

The calculated maximum cooling load maybe validated by taking measurements on an

existing system. For this method to beaccurate, measurements should be taken ona day that closely represents a designcooling day (maximum load conditions).For most systems, the peak load occurs ona hot, humid, sunny day with full internaloccupancy and equipment usage.

L.3.3.1 Peak cooling weather conditionsare usually easily recognized. Be careful toconsider the wet-bulb temperature. Internalconditions may be more difficult to identi-fy, but can be accurately estimated. Whendesign-day conditions occur, a measure-ment of chiller loading will define themaximum building cooling load. Measureand record:● chiller voltage across all phases;● chiller amperage readings of all phases;● outdoor conditions at the time of read-

ings (dry-bulb and wet-bulb tempera-tures, cloudiness, date, and time ofday); and

● entering and leaving chilled waterconditions and flow if available.

This information can be compared to therated capacity of the chiller to determinemaximum cooling load. For example, ifthe chiller is 95 percent loaded (electrical-ly), then the actual heat transfer can bedetermined from the manufacturer’s data.Alternatively, the chilled water flow,entering temperature, and leaving tempera-ture will define the heat transfer in Btu/hr.by:

Q = Flow (gal/min) x( TE N T E R I N G - TL E A V I N G) x 500

If desired, additional data may be com-piled for part-load weather conditions toestimate the cooling load profile.

L-4


1) The overall building cooling load (Q) can be expressed as:Q = QS P A C E + QR A + QS A

Where:Q S P A C E

= heat gain to the conditioned space,QRA

= heat gain to the return air side of airflow,Q S A

= heat gain to the supply side of airflow.

Each element of this equation may have both sensible and latent heat gain components.

2) QSPACE can be further defined as:Q S P A C E

= QW & R + QG L A S S + QP A R + QI N T

Where:QW&R

= heat gain through walls and roofs, both conduction and solar effectsQGLASS

= heat gain through glass, both conduction and solar effectsQPAR

= heat gain through partitions,QINT

= heat gain internal to the apace.

The elements of this equation, with the exception of QINT, will have sensible heat components only. If thespace under consideration has several zones (separately controlled areas), then QSPACE will be a summationof all zone space loads.

Furthermore, QINT can be expressed as:QINT = QP E O P L E + QL I G H T S + QE Q U I P + QI N F I L

Where:QPEOPLE

= heat gain from people within the space,QLIGHTS = heat gain from lighting within the space,Q EQUIP

= heat gain from equipment within the space,Q INFIL

= heat gain from infiltration.

Each element of this equation, with the exception of QLIGHTS, may have both sensible and latent heat gaincomponents.

3) Heat gain to the return side of airflow can be expressed as:QRA

= QP L E N U M + QR A F A N + QV E N T

Where:QPLENUM = heat gain to any return plenums or ductwork,QRAFAN = heat gain from any return air fans and motorsQVENT

= heat gain from fresh air ventilation.

Heat gain to return air plenums may include additional wall, roof, or floor heat gain, as well as apercentage of lighting heat gain. Heat gain to return air ductwork may also be present, although thesignificance is usually small.

Heat gain from fresh air ventilation is usually a very significant heat gain and should be carefullyconsidered. Although minimizing the amount of outside air can reduce the cooling load, extreme cautionmust be exercised because of problems that may develop with indoor air quality. (For additional informationregardiug indoor air quality, refer to ASHRAE 62-1989.)

Figure L-1. Cooling Load Calculation

L-5


4) Heat gain to the supply side of air flow may be expressed as:Q S A

= Q P L E N U M + QS A F A N

Where:QPLENUM = heat gain to any supply plenums or ductworkQSAFAN = heat gain from the supply fan and motor

Heat gain to supply air plenums may include additional wall, roof, or floor heat gain. Heat gain to supplyair ductwork may also be present, although the significance is usually small.

NOTE: For non-air systems (for example, packaged terminal air conditioners), QSA and QRA do not apply.

Figure L-1. Cooling Load Calculation (continued)

L.4 Perform Energy Analysis

The energy analysis determines how long,during a calendar year, the chiller is with-in certain ranges of its full load capacity.Knowing this information will assist theengineer in calculating energy costs fordifferent chiller selection alternatives. Fourranges of operation are sufficient for mostanalyses. More ranges will provide addi-tional accuracy. Energy calculations,especially computer-generated ones, willusually be able to output more than four;however, chiller performance is usuallygiven at four points -25, 50, 75, and 100percent of full-load capacity. In some cas-es, especially when evaluating a retrofit,the peak load will not equal 100 percent ofthe chiller capacity. When this is the case,the ranges describing the building’s part-load requirements will have to be alignedto corresponding capacity ranges for thechiller under consideration. This type ofadjustment also applies when multiplechillers are being used, such as in a centralchilled water plant.

L.4.1 Types of Energy AnalysesThere are several types of energy analyses,some of which are more complex (and

accurate) than others. The degree-day andbin methods are simple and can be calcu-lated manually. Both are accurate forperforming an energy analysis on simplebuildings. A dynamic method requiring theuse of a computer program is essential forperforming an energy analysis of complexbuildings.

L.4.1.1 The degree-day method uses theconcept of balance point. The balancepoint for a building is the outside tempera-ture at which the rate of heat transmissionto or from the building is zero. Whenoutside temperatures are different than thebalance point temperature, there will besome correlation between the temperaturedifference and energy usage. The accuracyof this type of calculation will vary basedon the building’s operational characteris-tics. The degree-day method works bestwhen most of the load results from varia-tions in the outdoor temperature.

L.4.1.2 The bin method uses the balancepoint concept, but breaks temperature datafor a locality into ranges or bins. Typi-cally, five-degree bins are used. Each binwill include the number of hours per yearthe locality experiences that particular

L-6


temperature range. For example, Nashvillewill experience 650 hours of 10° C(50° F) to 12° C (54° F) conditions duringa typical year.

L.4.1.2.1 The accuracy of the bin methodis somewhat higher that the degree-daymethod. Hours are used as an incrementinstead of days. Because the balance pointconcept is used, the same problems willoccur if the building load does not closelyfollow the outdoor temperature. Someenhancements exist for both the degree-daymethod and the bin method. The variabledegree-day method and the modified binmethod are attempts to adjust for variablessuch as solar gain, thermostat settings, andinternal loads.

L.4.1.2.2 Heating and cooling degreedays have been published for most locali-ties. A source for this data is the AirForce Manual AFM88-29, EngineeringWeather Data.

L.4.1.3 Although the simplified methodsmentioned above can be accurate for sim-ple buildings, they will not be acceptablefor buildings of complexity (high internalloads and sophisticated system operationalcharacteristics). Also, it is difficult toaccurately predict energy consumptionwith simplified methods when the efficien-cy of the cooling or heating plant variessignificantly with load. When simplifiedmethods are not acceptable, a dynamicmethod simulating hourly load calcula-tions, and system and plant interactionshould be used. This method requires acomputer program because of the com-plexity and repetitive nature of thecalculations.

L.4.1.3.1 Energy analysis programs re-quire the building to be modeled. The pro-gram will operate on the building modelwith hourly weather data to calculate cool-ing (and heating) load for each hour of theyear. The resultant loads are related to thesystem model (for example, air handlersand VAV boxes) to determine energyrequirements for the heating/cooling plant.The system energy requirements are thenrelated to the plant model (for example,chillers and boilers) to determine ultimateenergy usage. While these programs arevery accurate and can simulate many typesof systems and plants, they are complexand require a significant amount of time tolearn and become proficient.

L.5 Establish Annual CoolingLoad Profile

Once an hourly load profile has been de-veloped, a simplified cooling load profileshould be established. For example, thehourly load data can be grouped in rangesof O to 25 percent, 25 to 50 percent, 50 to75 percent, and 75 to 100 percent of peakcooling load. The actual ranges usedshould be selected to coincide with knownranges of chiller efficiency. These hourlyvalues will be used through the remainderof the chilled water system selection andcomparison process.

L.5.1 Energy Conservation Impact onChiller Selection

Energy conservation improvements canhave a significant impact on the coolingload of a building. Improvements imple-mented within the previous five years and

L-7

Appendix L – Fundamentals of Cooling Load and Energy Analysis

planned over the next five years must beconsidered. Conservation projects canreduce the required capacity of the retrofitor replacement chiller. In addition, if anenergy conservation project can be tiedinto the replacement of an existing chiller,it is possible. to obtain Energy Conserva-tion Investment Program/Federal EnergyManagement Program (ECIP/FEMP) fund-ing for both. Future energy conservation

projects may reduce the required chillercapacity. In the meantime, peak loads willstill occur at existing levels. This situationmust be addressed by the engineer. If achiller is oversized, optimizing that chillerfor the actual load when changing to a newrefrigerant can result in significant firstcost savings. A newly optimized retrofitmay be comparable in efficiency to a new,high-efficiency chiller.

L-8

Appendix M – Evaluating Water Chillers for Replacement or Retrofit Potential

Appendix M — Evaluating Water Chillers forReplacement or Retrofit Potential

ABSTRACT: This appendix provides procedures and guidelines for evaluating replacement andretrofit alternatives for existing water chillers based on their age, mechanical condition,operating efficiency, and criticality to the building(s) or system(s) they serve. The decision toreplace or retrofit a chiller is to be made based on comparing life-cycle costs (LCC) for bothoptions.

M.1 Introduction

The purpose of this appendix is to describea procedure for evaluating existing chloro-fluorocarbon (CFC) water chillers forreplacement or retrofit to environmentally-friendly refrigerants.

M.1.1 AssumptionsThis analysis procedure assumes:●

●

●

●

●

The equipment inventory survey hasbeen completed and the field surveydata sheets are available for use in thisanalysis.The chiller life expectancy for all alter-natives and the study life of the LCCanalysis is 20 years.Any existing chiller older than 15 yearsis not to be considered for retrofit dueto its limited remaining life and loweroperating efficiencies common to chill-ers of that age.The building maximum cooling loadand the building annual cooling loadprofile have been estimated by theprocedure described in Appendix L,Fundamentals of Cooling Load andEnergy Analysis.The interest (discount) rate used in thelife-cycle cost analysis is obtained from

Energy Prices and Discount Factors forLife Cycle Cost Analysis (NISTIR-3273-7, 1994), available from theNational Institute of Standards andTechnology (NISI’). The interest ratecurrently used for federal energy con-servation projects is four percent (ex-cluding inflation).

M.1.2 ApplicabilityThis procedure is applicable to existingwater chillers using CFC-11, CFC-12,CFC-113, CFC-114, CFC-115, andCFC-500 refrigerants.

M.2 Evaluation Procedure

The following six components will beevaluated:1)2)3)

4)5)

6)

age assessment;load assessment;original equipment manufacturer(OEM) analysis request;new equipment data requests;cost estimates for retrofit, new equip-ment, existing equipment/equipmentroom modifications; andLCC analysis of alternatives selected.

In addition, chilled water systems locatednear other systems should be evaluated for

M-1

Appendix M — Evaluating Water Chillers for Replacement or Retrofit Potential

potential central chilled water plant devel-opment (see Appendix O, Assessing thePotential of Central Chilled Water Plants).

M.2.1 Age AssessmentThe age of a chiller may be obtained fromthe Work Information Management System(WIMS) Refrigerant Management Soft-ware, equipment survey forms, manuf-acturer’s data, or from the manufacturer’slocal representative. If the chiller is morethan 15 years old, it is probably too oldfor a cost-effective retrofit and should notbe considered.

M.2.2 Load AssessmentThe capacity of chiller replacements orretrofits should closely match the maxi-mum building cooling load (estimated byprocedures described in Appendix L,Fundamentals of Cooling Load and EnergyAnalysis). A change in chiller capacity willapply to situations where installed systemcapacity is oversized or where users haveundertaken energy conservation project(s)reducing the cooling demand on thechiller.

M.2.2.1 There are two circumstancessupporting the cost-effectiveness of a newchiller.1)

2)

The capacity of the existing chillerexceeds the maximum system coolingload. In this situation, a smaller chillercan be installed, resulting in lowerfirst-cost (replacement option), andlikely lower operating costs.The efficiency of the existing chiller islow (higher kW/ton) compared tochillers currently available. In thissituation, a more efficient chiller can

M-2

be installed which will result in loweroperating costs.

M.2.2.2 Four conditions favor a retrofit.1)

2)

3)

4)

The chiller has significant useful ser-vice life left, with newer chillers beingthe more favorable candidates.The chiller requires repair. Retrofitsaccomplished at the time of scheduledrepairs will be more cost-effectivebecause some of the scheduled repairswill be performed as a result of theretrofit.The chiller is servicing facilities/operations that cannot tolerate lengthydowntime of the cooling system. Aretrofit may be accomplished sooner,and with less downtime, than replace-ment. In this situation, the cost ofdowntime may encourage a retrofit.The chiller is relatively new and hasbeen manufactured for ease of retrofit.In many cases, conversion will resultin a loss of efficiency and/or capacitywhen a new refrigerant is installed. Inmost cases, it is most cost-effective tocontinue to operate the chiller (becauseof its high operating efficiencies) withthe CFC refrigerant and take advantageof its efficiency as long as possible.Ensure it is equipped with a high-effi-ciency purge unit on low-pressurechillers (for example, CFC- 11 andCFC-113 machines).

M.2.3 OEM Analysis RequestChillers less than 15 years of age shouldbe analyzed for retrofit potential. Contactthe OEM with regard to chillers of theirmanufacture. OEM analysis requestsshould be made only for chillers that areconsidered probable candidates for retrofit


because some manufacturers may chargefor the analysis. Allow eight weeks lead-time in making requests because somemanufacturers will have a backlog.

M.2.3.1 The OEM analysis should in-clude performance data for a “drop-in”retrofit, a “maintained capacity” retrofit,a “maintained efficiency” retrofit, and“optimize to meet current cooling load”retrofit. A drop-in retrofit is the mostbasic of the four. The old refrigerant isreplaced with new refrigerant and anychanges necessary to accommodate thenew refrigerant are made (for example,seals, lubricating oil). A maintained capac-ity retrofit includes all components of adrop-in retrofit, as well as any mechanicalchanges necessary to maintain the originalrefrigeration capacity. The maintainedcapacity retrofit typically results in a lossof efficiency. A maintained efficiencyretrofit is similar to the maintained capaci-ty retrofit, except the original efficiency ofthe chiller is maintained, typically at someloss of refrigeration capacity. The “opti-mize to meet current cooling load” retrofitoptimizes by derating a chiller with excesscapacity. This can result in greater effi-ciencies due to the large heat exchangeareas in comparison to the load. Be awarethat any or all four of these retrofit typescan be accomplished for a chiller, but willnot necessarily produce the requiredchilled water supply temperature or use theexisting condenser water temperature.Therefore, be diligent to request the OEManalysis with specific water temperatures,not just capacity.

M.2.4 New Equipment Data RequestIf chiller replacement is a viable option, apreliminary selection should be made.Refer to Appendix N, Chiller SelectionGuide, for assistance in making this selec-tion. More than one selection may need tobe considered. Engineering data for newchillers should be requested from the localmanufacturer’s representative. The engi-neering data should, at a minimum, con-tain the chiller cost; design operatingconditions (capacity and efficiency); part-load efficiency at 25, 50,of full-load capacity; andeach chiller.

M.2.5 Cost Estimates

and 75 percentdelivery time for

Cost estimates must be prepared for thevarious options under consideration. Costsfor chiller retrofit, equipment room modi-fications, new chillers, and related systemmodifications must be determined beforean LCC analysis of all options can becompleted.

M.2.5.1 The cost estimate for chillerreplacement and retrofit options shouldinclude chillers, their components, andaccessories. These estimates may be deter-mined through manufacturer’s representa-tives, construction cost estimating guides,or similar completed construction projects.

M.2.5.2 The work and cost required tomodify mechanical rooms to comply withthe ASHRAE 15-1994 must be deter-mined. This cost is essentially identical forthe replacement and retrofit options. Ap-pendix J, Application of ASHRAE Equip-ment Room Design Requirements, contains

M-3


a summary of ASHRAE 15-1994. Exam-ples of these modifications include new orupgraded ventilation systems, refrigerantleak detection and monitoring systems,isolation from open-flame equipment, andpiping of the refrigerant system relief andpurge discharge to the outdoors.

M.2.5.3 A preliminary design of theentire system covering the cooling tower,and chilled water and condenser coolingwater distribution systems may be neces-sary if a smaller replacement chiller isbeing considered. Budget pricing for thechiller may be obtained from one or morechiller manufacturers. Cost estimates forthe rest of chiller plant components will bebased on existing equipment that can beused as-is, existing equipment that willrequire some changes for reuse, and equip-ment that requires replacement.

M.2.6 LCC AnalysisOnce the potential retrofit and replacementalternatives for the chiller have beenreduced to a manageable number (two orthree), it will be necessary to perform adetailed LCC analysis of these alternativesto select the one most cost-effective. TheLCC analysis will require calculating theannual energy cost for each of the alterna-tives. This calculation method is describedin the example in section M. 3.

M.3 Example of Evaluation

The following assumptions, figures, andtables provide the necessary information toassess whether an existing chiller shouldeither be retrofitted or replaced. TableM-1, Chiller Operating Profile, summariz-es the chiller operating profile for oneyear. Table M-2, Chiller Part-Load

Efficiencies and Initial Costs, provides thechiller efficiencies and chiller costs for thevarious alternatives considered in thisexample. For this example, three alterna-tives, (1) a drop-in retrofit, (2) a same-capacity retrofit, and (3) a new unit willbe considered feasible alternatives.

M.3.1 AssumptionsThe following assumptions were made indeveloping the examples in this appendix.

M.3.1.1 From the utilities data sheets, theaverage energy cost is $0.051/kWh.

M.3.1.2 The estimated cost to upgradethe mechanical room to meet ASHRAE15-1992 is $10,200.

M.3.2 Feasible Alternatives EnergyCost ($ENERGY)

The first step in the evaluation is to calcu-late the annual energy cost for all alterna-tives for retrofit or replacement. Thecalculations are shown in Figure M-1,Calculate $ENERGY.

M.3.3 Present Value ($PV) FormulaA review of the present value formula ispresented prior to calculating the LCC ofthe feasible alternatives. This analysisassumes a 20-year study period and anexpected life of 20 years for all equip-ment. Because the useful life of all equip-ment is assumed to be the same and onlylasts through the study period, $REMAINis zero. None of the capital equipment isreplaced during the study period, so $RE-PLACE is also zero. Because maintenanceis assumed identical among the alterna-tives, it will not impact the PV for anyalternative. This formula is shown in Fig-ure M-2, Present Value ($PV) Formula.

M-4


Table M-1. Chiller Operating Profile

Annual Cooling Four-Point Load Profile

25% of Maximum 50% of Maximum 75% of Maximum Maximum LoadUnit No.

Tons Hours Tons Hours Tons Hours Tons Hours

Chiller 1 65 1,000 130 2,500 195 3,000 260 500

Table M-2. Chiller Part-Load Efficiencies and Initial Costs

Full Load Part-had Efficiency InitialCapacity Cost(1)

Alternative (tons) 25% 50% 75% 100% ($)

0. Unchanged 260 0.71 0.58 0.58 0.61 -–-

1. Drop-in(2) 260 1.34 0.81 0.73 0.70 22,000

2. Same Capacity 260 1.04 0.66 0.60 0.58 38,000

3. Same Efficiency(3) N/A N/A N/A N/A N/A N/A

4. New Unit(4) 260 1.04 0.66 0.60 0.58 72,000

(1) Initial cost includes installation, but not costs tomodify the mechanical room to meet ASHRAE

(3) Not available.

15-1962. (4) New chiller using HCFC-123, selected to operate atoriginal conditions. The part-load efficiencies are

(2) This unit was manufactured to be directly convert- the same as Alternative 2 because they are essen-ible to HCFC-123. The original capacity ratings tially identical machines.were based on its performance using HCFC-123.Therefore, there is no capacity penalty for thedrop-in retrofit alternative.

M-5


$ENERGY =

Where:$ENERGY =EFFxx%

=HRS xx%

=L O A Dxx% =$/kWh =

{(EFF 25%)(HRS 25%)(LOAD 25%) + (EFF50%)(HRS 50%)(LOAD 50%) +(EFF 75%)(HRS 75%)(LOAD 75%) + (EFF100%)(HRS 100%))(LOAD 100%)}($/kWh)

estimated annual energy cost for chiller operation ($/year)chiller efficiency at xx% of maximum capacity (kW/ton)hours of chiller operation at xx% of maximum capacity (hours/year)cooling load at xx% of maximum capacity (tons)average cost of electricity from the utilities data sheets

For Alternative 1: Drop-In Retrofit:$ENERGYAlt1 = {(1.34)(1,000)(65) + (0.81)(2,500)(130)+

(0.70)(500)(260)} (0.05 1)$ E N E R G Y Alt1 = $ 4 4 , 2 9 0

For Alternative 2: Same Capacity Retrofit:$ENERGY Alt2 = {(1.04)(1,000)(65) + (0.66)(2,500)(130)+

(0.58)(500)(260)} (0.051)$ E N E R G Y Alt2 = $ 3 6 , 1 3 0

For Alternative 4: New Unit:$ E N E R G Y Alt4 = {(1.04) (1,000)(65) + (0.66)(2,500)(130) +

(0.58)(500)(260)} (0.05 1)$ E N E R G Y Alt4 = $ 3 6 , 1 3 0

(0.73)(3,000)(195) +

(0.60)(3,000)(195)

(0.60)(3,000)(195)

Figure M-1. Calculate $ENERGY

+

+

$PV

Where:$PV$INITIAL

$REPLACE(P/F, i%,N)(P/A, i%,N)

i%N$ENERGY$MAINT$REMAIN

= $INITIAL + $REPLACE(P/F,i%,N) + ($ENERGY + $MAINT)(P/A,i%,N) -$REMAIN(P/F,i%,N)

= present value of the life-cycle costs associated with a particular alternative ($)= total initial cost of a particular alternative ($), including the cost for upgrading

the mechanical room= future replacement cost (assumed as zero ($))= present value of a future cash flow at an interest rate of i% for N years 1,2

= present value of an annually-recurring cash flow at an interest rate of i%for N year1,2

= interest rate (discount rate) for federal energy conservation projects (%)2

= study period (years)= estimated annual energy cost of chiller operation ($/year)= annual maintenance costs ($)= remaining value of equipment at the end of N years (assumed to be zero ($))

1 This factor is obtained from any engineering economics text2 NISTIR 85-3272-7

Figure M-2. Present Value ($PV) Formula

M-6


$PV = $INITIAL + $ENERGY(P/A,i%,N)

For Alternative 1: Drop-in Retrofit:$ P VAlt1

= $22,000 + $10,200 + {$44,290X (P/A,4%,20)}= $32,200 + $44,290(13.59)= $32,200 + $601,900

$ P VAlt1= $634,100

For Alternative 2: Same Capacity Retrofit:$ P VAlt2

= $38,000 + $10,200 + {$36,130X (P/A,4%,20)}= $48,200 + $36,130(13.59)= $48,200 + $491,000

$ P VAlt2= $539,200

For Alternative 4: New Unit:$ P VAlt4

= $72,000 + $10,200+ {$36,130X (P/A,4%,20)}= $82,200 + $36,130(13.59)= $82,200 + $491,000

$ P VAlt4= $573,200

Figure M-3. Calculate $PV

M.3.4 Feasible Alternatives for PresentValue of LCC ($PV)

The next step in evaluating water chillersfor replacement or retrofit is to calculatethe present value of the LCC for the feasi-ble alternatives. These calculations areshown in Figure M-3, Calculate $PV.

M.3.5 Example ConclusionSelect the alternative with the lowestpresent value of the LCC. Select Alterna-tive 2: Same Capacity Retrofit.

M.4 List of MajorManufacturers

For further information on replacementand retrofit, contact the following:

Carrier Air Conditioning CompanyCarrier Pkwy., P.O. Box 4808Syracuse, NY 13221(315) 432-6000

Snyder General Corporation13600 Industrial Park Blvd.P.O. Box 1551Minneapolis, MN 55440(612) 553-5330


York International Corporation631 South Richard Ave.P.O. Box 1592York, PA 17405-1592(717) 771-7890

M-7 (M-8 Blank)


Appendix N — Chiller Selection Guide


ABSTRACT: This appendix provides guidelines and procedures for selecting water chillers.There are a variety of chillers available for consideration. Each application will require attentionto such items as efficiency, availability of fuel sources, load matching, initial cost, annualmaintenance cost, and annual operating cost.

N.1 Introduction

This appendix is a guide for engineersselecting and optimizing water chillers.The selection of a chiller is the mostimportant component of chilled watersystem optimization. All options for eachsituation must be examined and a selectionmade based on the lowest life-cycle cost(LCC). Because site-specific condi-tions-lack of a waste heat source, or alow cost of electricity relative to naturalgas–certain alternatives can immediatelybe eliminated. Figure N-1, Chiller Selec-tion Flowchart, illustrates a broad summa-ry of the chiller selection process. TableN-1, Chiller Selection Guide Summary,provides a summary of various chillertypes, including typical costs, sizes, andefficiencies.

N.1.1 ApplicabilityThe selection process discussed in thisappendix applies to chilled water systemsconsisting of single or multiple chillerinstallations. Chiller types considered inthe selection process should include ab-sorption chillers - steam, hot water, anddirect-fired; electric chillers - scroll, recip-rocating, rotary screw, and centrifugal;ammonia chillers; and natural gas engine-driven chillers.

N.1.2 Selection ProcedureThe guidelines for selecting the mosteffective chiller(s) are broken down intotwo parts.

N.1.2.1 Part one describes various typesof chillers, discusses the advantages anddisadvantages of each, and suggests wheneach chiller type should be considered.The chiller information in this appendix isgeneral in nature. More detailed informa-tion should be sought from chiller manu-facturers. A partial list of major chillermanufacturers can be found in N.5.

N.1.2.2 Part two describes a generalselection procedure.

N.1.2.3 Chiller efficiency is expressed bythe ratio of energy input divided by cool-ing capacity. Typical units are kilowattsper ton (kW/ton) of refrigerant capacity orpounds of steam per hour per ton(steam/hr/ton) of refrigeration capacity.

N.1.2.4 Chillers are heat “pumps” thatare designed to transfer heat from onesource to another. The energy required to“pump” the heat is usually less than thecooling capacity available. Because thisconcept is somewhat different from thetraditional definition of efficiency, theterm “coefficient of performance” (COP)

N-1

Figure N-1. Chiller Selection Flowchart


Table N-1. Chiller Selection Guide Summary

Chiller Selection Guide

Available Equipment CostTonnage (chiller only)

Equipment Type Range $/Ton Full Load Efficiency COP

Single-stage Steam Absorption 100-1700 260-650 15-20 lb/hr/ton 0.85-0.63

Two-stage Steam Absorption 100-1500 460-600 5-10 lb/hr/ton 0.95-1.05

Direct-fired Absorption 100-1500 530-860 10-15 Mbh/ton(1) 1.2-0.80

Electric Scroll 20-80 340-380 0.85 -2.0 kW/ton 4.0 -1.8

Electric Reciprocating(3) 20-200 340-470 0.90-1.10 kW/ton 3.9 -3.2

Electric Rotary Screw(2) 70-500 200-400 0.75-0.85 kWlton 4.7 -4.1

Electric Centrifugal 100-1500 210-300 0.55-0.80 kW/ton 6.4 -4.4

Natural Gas Engine-driven 100-500 750->1000 8-9 Mbh/ton(1) 1.4 -1.3

(1) Mbh = 1000 Btu/hr (3) Available with ammonia refrigerant in 20 to 400

(2) Available with ammonia refrigerant in 30 to 300 tons

tons

is often used to relate efficiency. COP issimply the cooling capacity divided by theenergy input. When equivalent units areused, the COP will be a dimensionlessnumber, usually greater than one.

N.1.2.5 Chiller efficiency and perfor-mance can not always be evaluated forpeak load. Most cases require that chillersbe evaluated based on part-load perfor-mance. Part-load performance is the me-chanical efficiency of the machine operat-ing at various percentages of full load.

N.2 Chiller Descriptions andPerformance Characteristics

The following sections describe the com-monly available chiller types and theirapplications.

N.2.1 Single-Stage Steam or Hot WaterAbsorption Chiller (Water-Lithium Bromide Solution)

Single-stage steam or hot water absorptionchillers should be considered only whenthere is sufficient excess heat energy in theform of steam or hot water. Steam inletpressures at the chiller can not exceed 12to 14 psig with maximum temperatures of1710 C (340° F). Hot water must be avail-able at 93° C (200° F) to 188° C(370° F). Cooling capacities range from100 to 1700 tons with chilled water supplytemperatures in the range of 4° C (40° F)to 10° C (50° F).

N.2.1.1 A single-stage steam or hot waterabsorption chiller uses this heat energy toboil a dilute solution of lithium bromideand water. The resulting refrigerant vapor

N-3


Figure N-2. Single-Stage Steam Absorption Chiller Part-bad Performance

is condensed in the condenser section. Theliquid refrigerant then passes through athrottling device and enters the evaporatoras a saturated liquid at approximately 4° C(40° F). The liquid refrigerant is collectedwithin and continuously sprayed over theevaporator tube bundles, thereby coolingthe water. The resulting refrigerant vapormigrates to the absorber section where it isagain condensed on the absorber tubebundles. Cooling tower water is used toremove heat from the absorber tubes. Thediluted solution is then pumped back to theconcentrator.

N.2.1.2 Single-stage absorption chillersare approximately 20 percent more expen-sive than a comparable electric centrifugalchiller. However, if excess waste heat

energy is available, there is a potential forenergy cost savings.

N.2.1.3 Single-stage absorption chillerscost from $260 to $650 per ton of refrig-eration capacity. Their efficiencies rangefrom 15 to 20 lb/hr/ton with COPS rangingfrom 0.85 to 0.63. Figure N-2, Single-Stage Steam Absorption Chiller Part-LoadPerformance, shows a single-stage absorp-tion machine can operate as low as tenpercent of its maximum capacity. Thechiller is most efficient at 50 to 80 percentof maximum capacity.

N.2.2 Two-Stage Steam or Hot WaterAbsorption Chillers (Water-Lithium Bromide Solution)

Two-stage steam or hot water absorptionchillers are similar to single-stage, with the

N-4


Figure N-3. Two-Stage Steam Absorption Chiller Part-Load Performance

exception that a two-stage machine useshigher steam pressures or hot water tem-peratures and two concentrator stages. Forthese machines, steam pressures in therange of 60 to 115 psig and hot watertemperatures up to 188° C (370° F) can beused. Cooling capacities range from 100 to1500 tons.

N.2.2.1 Two-stage absorption chillerscost from $460 to $600 per ton. They re-quire waste heat energy to be cost-effectiveand are approximately 2 to 2.5 times asexpensive as a comparable electric centrif-ugal chiller.

N.2.2.2 Full-load efficiencies range from5-10 lb/hr/ton with COPS ranging from2.7 to 1.3. Figure N-3, Two-Stage SteamAbsorption Chiller Part-Load

Performance, shows a two-stage absorp-tion machine can operate as low as tenpercent of its maximum capacity. Thechiller is most efficient at 60 to 80 percentof maximum capacity.

N.2.3 Direct-Fired Absorption Chiller(Water-Lithium BromideSolution)

Direct-fired chillers use natural gas, fueloil, or waste heat in the form of cleanexhaust gases (T> 316° C (600° F)) fromsources such as gas turbines and diesel en-gines. Direct-fired gas absorption chillersare available only in two-stage configura-tions. They bum approximately 10 to 15cubic feet of natural gas per hour per tonof cooling. These machines range in sizefrom 100 to 1500 tons.

N-5

Appendix N – Chiller Selection Guide

Figure N-4. Direct-Fired Absorption Chiller Part-Load Performance

N.2.3.1 Direct-fired absorption chillershave, in general, the same configurationand processes as two-stage steam or hotwater absorption chillers with the excep-tion of the input energy source. A uniquefeature of most direct-fired absorptionchillers is they also act as a heater. Mostmanufacturers refer to a direct-firedabsorption chiller as a chiller-heater.

N.2.3.2 The heater portion of the direct-fired chiller operates by the energy sourcein the first-stage generator heating thediluted lithium-bromide solution. Thisdrives off refrigerant vapor and leavesconcentrated solution. The hot refrigerantvapor’s heat is transferred to the building’shot water system via an auxiliary heat ex-changer or a heat exchanger internal to theunit. The condensed refrigerant liquid

N-6

returns to the first-stage generator andcompletes the cycle.

N.2.3.3 A direct-fired absorption chilleris approximately 2.5 times more expensivethan a comparable capacity electric cen-trifugal chiller, but is competitive withtwo-stage steam or hot water absorptionchillers.

N.2.3.4 Direct-fired absorption chillersrange in price from $530 to $860 per tonof refrigeration capacity. Their fill-loadefficiencies are approximately 12,000 Btuper hour per ton (12 Mbh/ton) of refriger-ation capacity with COPS ranging from 1.2to 0.80. Figure N-4, Direct-Fired Absorp-tion Chiller Part-Load Performance, showsa direct-fired machine can operate as lowas 25 percent of its maximum capacity.


Figure N-5. Electric Scroll Chiller Part-Load Performance

The chiller is most efficient at 70 to 90percent of maximum capacity.

N.2.4 Electric Scroll ChillerThe electric scroll chiller is the smallest ofthe electrical chillers. It is available inboth water-cooled and air-cooled config-urations. Sizes range from 20 to 80 tons ofrefrigeration capacity. Due to their smallsize, scroll chillers should not be consid-ered for central plant applications. Goodapplications for scroll chillers includeareas that have special temperature andhumidity requirements that packaged di-rect-expansion equipment can not meet.

N.2.4.1 The general operating character-istics are similar to a reciprocating chiller.The main difference is, in lieu of a piston-type compressor, the scroll uses a rotary-

type compressor. The compressor operatesby rotating a spiral-shape scroll, compress-ing the vapor as it is forced through thescroll.

N.2.4.2 Scroll chillers can be manifoldedtogether to provide multiple staging andload matching capability. Manifoldedscroll chillers can be used as an alternativeto reciprocating units. This is most effec-tive when the maximum load exceeds asingle-scroll chiller capacity but falls in therange of a reciprocating chiller.

N.2.4.3 Scroll chillers cost $340 to $380per ton of refrigeration capacity. Theirfull-load efficiencies range from 0.85 to2.0 kW/ton with COPS in the range of 4.0to 1.8. Figure N-5, Electric Scroll ChillerPart-Load Performance, shows an electric

N-7


Figure N-6. Electric Reciprocating Chiller Part-Load Performance

scroll machine can operate as low as 25percent of its maximum capacity. Thechiller is most efficient at 25 to 50 percentof maximum capacity.

N.2.5 Electric Reciprocating ChillerOf the chillers considered, the recipro-cating chiller has the lowest first cost, butalso the lowest efficiency. Initial cost isfrom $340 to $470 per ton with full-loadefficiencies from 0.90 to 1.10 kW/ton.Reciprocating chillers are available onlywith HCFC-22 or ammonia as the refriger-ant (see section N.2.8). Reciprocatingchillers are available in either air-cooled orwater-cooled configurations.

N.2.5.1 Air-cooled reciprocating chillersrange in capacity from 20 to 130 tons.Water-cooled chillers range in capacity

from 50 to 200 tons. The full-load effi-ciency of an air-cooled system is usuallyless than a water-cooled system despite theenergy required by the water cooler andcondenser water pump. An air-cooled sys-tem requires more space than a water-cooled system, because an air-cooledcondensing unit requires more surface areathan a water-cooled condensing unit. Fig-ure N-6, Electric Reciprocating ChillerPart-Load Performance, shows an electricreciprocating machine can operate as lowas 15 percent of its maximum capacity.The chiller is most efficient at 30 to 50percent of maximum capacity.

N.2.6 Electric Rotary Screw ChillerThe rotary screw chiller is similar to thescroll chiller; neither use piston compres-sors. The rotary screw chiller uses two

N-8


Figure N-7. Electric Rotary Screw Chiller Part-Load Performance

rotors for the compression cycle. A malerotor is driven by the motor which com-presses refrigerant gas between a femalerotor.

N.2.6.1 Rotary screw chillers offer higherefficiencies than reciprocating chillers ofequal capacity, although they will besomewhat more expensive. Screw chillersare available only with either HCFC-22 orammonia as the refrigerant.

N.2.6.2 Screw chillers are available ineither air-cooled or water-cooled configu-rations. The air-cooled machines range incapacity from 70 to approximately 400tons. The water-cooled type ranges incapacity from 100 to 500 tons. The full-load efficiency of a screw chiller is

generally around 0.80 kW/ton with COPSranging from 4.7 to 4.1. Among compara-ble-size machines, the part-load efficiencyof a screw chiller is better than the part-load efficiency of a reciprocating chiller.When load matching can not be accom-plished through staging individual chillers,this favorable efficiency characteristic ofthe screw chillers should be considered.Based on energy efficiency, a water-cooledscrew chiller is a better selection than anair-cooled chiller. Figure N-7, ElectricRotary Screw Chiller Part-Load Perfor-mance, shows an electric screw machinecan operate as low as ten percent of itsmaximum capacity. The chiller is mostefficient at 35 to 55 percent of maximumcapacity.

N-9


Figure N-8. Electric Centrifugal Chiller Part-Load Performance

N.2.7 Electric Centrifugal ChillerElectric centrifugal chillers use hermetical-ly sealed or open-drive compressor/motorassemblies. They come with single-, two-,or three-stage compression cycles. Refrig-erant vapor is accelerated through theimpeller, increasing the pressure andtemperature. The high-temperature vaporenters the condenser (a shell and tube heatexchanger) where it is cooled to saturationby condenser water passing through thetubes. The liquid refrigerant then passesthrough a metering device, such as anorifice plate, which lowers the pressure.The low-pressure liquid refrigerant entersthe evaporator (a shell and tube heat ex-changer) where it evaporates by heat trans-fer from the chilled water passing throughthe tubes, thereby chilling the water. Fi-

N-10

nally, the low-pressure refrigerant vaporreturns to the compressor.

N.2.7.1 Electric centrifugal chillers havethe highest full-load efficiency of theelectric chillers discussed. The averagefull-load efficiency will be approximately0.55 to 0.80 kW/ton with COPS rangingfrom 6.4 to 4.4, depending on capacityand water temperatures. First cost of elec-tric chillers ranges from $210 to $300 perton. Centrifugal chillers can operate withmany of the environmentally friendly re-frigerants, such as HCFC-123 andHFC-134a. Electric centrifugal chillersrange in size from approximately 100 to1500 tons. The only available configu-ration is water-cooled. Figure N-8, Elec-tric Centrifugal Chiller Part-Load


Performance, shows an electric centrifugalmachine can operate as low as ten percentof its maximum capacity. The chiller ismost efficient at 55 to 85 percent of maxi-mum capacity,

N.2.8 Specialty ChillersTwo specialty chillers are discussed in thefollowing sections. These chillers arevariations of the electric chillers.

N.2.8.1 Ammonia chillers use ammoniain lieu of HCFC-22 as a refrigerant. Am-monia is available for use in reciprocatingor screw chillers, either air- or water-cooled. The screw chillers range in sizefrom 30 to 300 tons. The reciprocatingchillers range in size from approximately20 to a maximum of about 400 tons. Dueto the toxicity of ammonia, these chillersshould be considered only if they can belocated in a remote area away from thebuilding(s) they serve.

N.2.8.2 Natural gas engine-driven chillersuse a natural gas-fired engine rather thanan electric motor. Engine-driven chillersare only available with screw compressorsat the present time, but may be availablewith reciprocating compressors in the nearfuture. These chillers are water-cooled andsizes range from 100 to 500 tons. Therefrigerant used is HCFC-22. The efficien-cy is approximately 9.0 cubic feet/hour ofnatural gas per ton of cooling capacity.Engine-driven chillers are more expensivethan motor-driven chillers of comparablecapacity and require more maintenance.

N.3 Chiller Selection Procedure

This section outlines a step-by-step proce-dure for selecting chiller(s) for use insupport of Appendix M, Evaluating WaterChillers for Replacement or Retrofit Poten-tial and/or Appendix O, Assessing thePotential of Central Chilled Water Plants.Figure N-1 shows the flow logic for thisselection process.

N.3.1 Cooling Load ProfileIt is essential that the cooling load profilebe determined (see Appendix L, Funda-mentals of Cooling Load and Energy Anal-ysis). The site should be surveyed to deter-mine the available utilities. The followingis a step-by-step procedure.

N.3.1.1 Step 1- Determine availableinput energy sources. There are four po-tential input energy sources which shouldbe evaluated:● Waste heat energy

- Low-pressure steam (< 60 psig)- High-pressure steam (> 60 psig)- Hot water (93° C (200° F) to

188° C (370° F))- Hot gas (>316° C (600° F))

● Plant-generated steam- Low-pressure steam (12 to 15 psig)- High-pressure steam (60 to 115

psig)● Natural gas● ElectricSurvey the site and determine all availableenergy input types, including the opportu-nity for extending such services as natural

N-11


gas, steam, and electric from adjoiningsites. The cost of extending utility servicesfrom distant sites may be prohibitive.

N.3.1.2 Step 2- Because certain inputenergy services may not be available, avariety of chillers can be eliminated afteranalyzing their economic feasibility basedon the utility rate structures. Examples:1)

2)

If natural gas is not available, thennatural gas, direct-fired absorption andnatural gas, engine-driven chillersshould not be considered.If waste heat energy in the form ofsteam, hot gas, or hot water is notavailable, then additional chiller types,such as single- and two-stage absorp-tion chillers can be eliminated.

N.3.1.3 Step 3- Collect all possiblealternatives and compare each chiller’sunique characteristics to items such as loadmatching, space requirements, and specialhumidity and temperature requirements-By the process of elimination, certainchillers will be unacceptable. Example:

If the load profile shows a peak loadrequiring 1000 tons, the use of scrollor reciprocating chillers would not beconsidered cost-effective.

This step in Figure N-1 is not intended toproduce a single refined chiller systemselection, but a set of possible alternativesto be used in support of Appendices M andO. Example:

The chiller selection is to support aretrofit or replacement of a single250-ton centrifugal chiller. The onlyavailable input source is electric. Theavailable chiller options are limited toa single electric centrifugal, rotaryscrew, reciprocating, or a multiple

chiller installation using rotary screwsand reciprocating chillers.

Proper chiller selection matches the perfor-mance of single or multiple chillers to therequired load profile. Load matching re-quires the profile be scrutinized and dis-sected such that optimum chiller loadperformance is used.Example:

If the load profile reflects a 1000-tonpeak load, but a constant base load of250 tons exists, the use of multiplechillers should be considered. For thisexample, further assume electric chill-ers are the only available alternatives.Therefore, potential chiller selectionscould be a single centrifugal or rotaryused to match the constant 250 tonsand two 375-ton centrifugal or rotarychillers to match the remaining 750tons.

Characteristics for consideration in select-ing and matching chillers to load profilesare part-load performance, peak-loadperformance, initial cost, space require-ments, utility rate structures, and the avail-ability of alternative energy input sources.Example:

If natural gas is available and theelectric utility rate structure is suchthat high rates and demand charges areimposed, natural gas becomes attrac-tive. But in areas where the electricutility rate and demand charges arelow, relative to other energy sources,natural gas or fuel oil becomes lessattractive.

N.3.1.4 Step 4- Once chiller alternativeshave been refined, further analysis of eco-nomic feasibility should be continued asoutlined in Appendices M and O.

N-12


N.4 Recommendations forFurther Study

To further optimize chiller selection, thereare several areas which can be considered.Some gas and electric utility offer rebatesand purchase incentives for selecting chill-er and chiller plant accessories with high-efficiency performance.

N.4.1 Gas Utility RebatesSome gas utility companies provide rebatesand incentives for converting electric-driven chillers to natural gas engine-drivenchillers.

N.4.2 Chiller Heat RecoveryHeat dissipated from a natural gas engine-driven chiller should be considered forheat recovery. The available heat from theengine cooling fluid could be used topreheat domestic water or process heatingwater. Utilization of this waste heat canresult in significant reduction in LCC.

N.5 List of MajorManufacturers


McQuay/Snyder General Corporation13600 Industrial Park Blvd.,P.O. Box 1551Minneapolis, MN 55440(612) 553-5330


York International CorporationP.O. Box 1592York, PA 17405-1592(717) 771-7890

N-13 (N-14 Blank)


Appendix O – Assessing the Potential of Central Chilled Water Plants

Appendix O– Assessing the Potential ofCentral Chilled Water Plants

ABSTRACT: This appendix provides guidelines for determining the potential of replacingchillers in multiple locations with a single chilled water plant. The new plant can be acombination of retrofit and new chillers. The new, central location can either be a new structure,or an expanded, existing mechanical room. The concept can even include remotely locatedchillers tied into a common distribution system and operated as a combined plant.

O.1 IntroductionThe purpose of this appendix is to provideguidelines for determining the potential ofreplacing multiple chilled water systemswith a centralized chilled water plant.

O.1.1 AssumptionsThe following assumptions have been usedin the development of this appendix.● The equipment inventory survey has

been performed as described in Appen-dix H, AC/R Equipment Survey Guideand Equipment Data Collection SurveyForms, and the completed equipmentsurvey forms are available for use inthe assessment,

● The chiller life for the life-cycle cost(LCC) analysis and study life are20 years.

● The annual cooling load profile foreach existing chiller water system hasbeen estimated by the procedure de-scribed in Appendix L, Fundamentalsof Cooling Load and Energy Analysis.

● The interest (discount) rate used in theLCC analysis is obtained fromNISTIR-3273-7. The interest ratecurrently used for federal energy

conservation projects is four percent(excluding inflation).

This evaluation procedure applies to indi-vidual chilled water systems located sothey can be economically combined todevelop a central chilled water plant. Theoption of a new building to house theequipment will be evaluated along with thepossibility of expanding one or more exist-ing mechanical rooms.

O.1.2 AdvantagesSeveral advantages for conversion to acentral plant follow.1)

2)

3)

The potential for lower installationcost. Larger chillers cost less per tonand only one mechanical room wouldneed to be established or upgraded tomeet ASHRAE Standard 15-1994 (ETL91-7 requires ASHRAE 15-1994 befollowed for new construction, or whenchillers are retrofit or replaced).The potential for lower energy cost dueto controlled load matching and im-proved operating efficiency.The potential for lower maintenancecost (fewer chillers to maintain andmaintenance will be centralized).

O-1

Appendix O — Assessing the Potential of Central Chilled Water Plants

4)

5)

6)

Increased system reliability (equipmentredundancy in multi-unit installations).The centralization of condenser coolingwater system and water treatmentsystem.Total installed capacity of the centralplant may be significantly less than forthe separate systems.

O.2 Evaluation Procedure

The first requirement is to identify chillerclusters. Chiller clusters representingproposed chilled water plants are identifiedby overlapping “capacity radius” circlesdeveloped by following the instructions inAppendix H. The information from thefield survey, including the base map,should be reviewed. Each central chilledwater plant that has a lower LCC than thesum of the individual chillers (as deter-mined from Appendix M, EvaluatingWater Chillers for Replacement or RetrofitPotential) should be programmed forimplementation. Further analysis may bewarranted as described in Appendix P,Heat Recovery Alternatives for RefrigerantChillers arid Appendix Q, Assessing thePotential of Thermal Storage. The basicprocedure for assessing the potential ofchilled water plants is as follows.

O.2.1 Obtain DataObtain data from equipment survey formsand Appendix M for each chiller whosecapacity radius overlaps another’s indicat-ing a potential to combine. The capacityradius circles are based upon a radius ofone foot per ton. Example: a 100-tonchiller would have a 100-foot capacityradius (200 foot diameter). This rule ofthumb is based upon experience involving

typical costs associated with installing acentral system.

O.2.2 Determine Central Plant CapacityThe maximum cooling load on the centralplant will likely be less than the sum of theindividual loads if the buildings are dissim-ilar in construction, orientation, or usage.Dissimilarities such as these cause varia-tion between the time of peak cooling foreach separate system and for the centralplant. This variation will allow a lessermaximum load on the central plant thanthe sum of the loads for the separate sys-tems—a concept commonly referred to asload diversity. Load diversities (reduc-tions) of 10 to 20 percent from the sum ofthe separate loads are common for centralchilled water plants. To calculate themaximum central plant load electronically,merge the input data files from the sepa-rate systems into one file for the centralsystem and rerun the load analysis soft-ware. This will produce the most accurateresults. The other method to determine thisload is by performing hand calculations.Although not as accurate as the computermethod, the results can be close enoughfor an analysis of this level (see AppendixL, for manually-calculating load).

O.2.3 Select Central Plant ChillersRefer to Appendix N, Chiller SelectionGuide, for information concerning types,performance ratings, and costs for variouschillers. Use this guide to make a reason-able, preliminary selection of the centralplant chillers for this analysis.

O.2.4 Determine Central Plant LocationSurvey the site area, as defined by capaci-ty radius circles, to determine a location

O-2


for the potential central chilled waterplant. Evaluate the re-use of an existingmechanical room. the expansion of anexisting mechanical room, or the construc-tion of a new central plant building, anddetermine reasonable pipe routing. Poten-tial modifications to the equipment roomshould be determined (Appendix J, Appli-cation of ASHRAE Equipment Room De-sign Requirements) and conceptual sketch-es of the equipment layout and pipe rout-ing produced. The purpose of the sketchesand the determination of equipment roommodifications is to estimate the initial costsof the central chilled water plant.

O.2.5 Determine Distribution SystemRouting

The decision must be made concerning theinstallation of above-ground or under-ground distribution piping. Aesthetic con-cerns may always dictate undergroundpiping.

O.2.5.1 Above-ground piping should onlybe a consideration if there would be noprobability of freezing. If above-groundpiping is required in areas with a freezingpotential, freeze protection methods suchas heat tracing or a glycol solution shouldbe considered. If glycol is proposed, thenegative effect on chiller capacity andperformance must be included in the evalu-ation of the chillers.

O.2.5.2 Three underground piping sys-tems should be considered when estimatingsystem costs. They are field-insulatedsteel, pre-insulated, and high-densityplastic.

O.2.5.2.1 The first underground methodis simply black steel pipe that is field-insulated by the contractor, using afoamed-glass type of insulation with awaterproof covering to protect the pipefrom corrosion.

O.2.5.2.2 The second system is pre-insu-lated pipe as supplied by a piping manu-facturer. The carrier pipe in a pre-insulat-ed piping system can be steel, copper,stainless steel, aluminum, or polyvinylchloride (PVC), to name a few. Jacketmaterial is either PVC or polyethylene.The annular space between the carrier pipeand the jacket is filled with polyurethaneinsulation. Polyurethane provides the mostefficient insulation of commonly-usedmaterials for tempemtures to 1210 C(250° F). Typically, the material price forfield-insulated piping is less than for pre-insulated piping, but pre-insulated piping isless expensive to install. Contractors havedifferent views on which is the lowest costsystem but, from a performance perspec-tive, they are equal.

O.2.5.2.3 The third piping system is ahigh-density (HD) plastic piping system.Plastic piping offers a cost saving on initialpiping costs, but it must still be field-insu-lated like the black steel pipe. Pipe sizes< 2½" are available on rolled spools forease of installation and lower installationcosts.

O.2.6 Determine Pumping/PipingArrangement

New primary pumps must be added for thecentral chilled water plant. Evaluate re-using existing chilled water pumps to serve

O-3


as secondary pumps. Some pump modifi-cations, such as trimming the pump impel-ler, may be required. Evaluate pipingmodifications that must be made at theexisting pumps for this new use. Refer toBell & Gossett Bulletin Number TEH-775,Primary/Secondary Pumping ApplicationManual, for guidelines on prima-ry/secondary pumping. The secondarypumping loop, which serves individualbuildings, should use only two-way controlvalves at the end users (air-handling units)so the chilled water flow can vary with thecooling load. Consider the possibility ofinstalling variable-speed drives on thesecondary pumping system.

O.2.7 Engineering AnalysisThe engineering analysis consists of com-paring the LCC analysis of the individualchillers in the cluster to the proposed cen-tral chilled water plant. The annual energyusage and projected maintenance costsmust be included. The analysis will in-clude engineering and construction costestimates. The construction cost estimatemust include:● all new and modified pumps,● piping,● equipment room modifications,● cooling towers,● chemical treatment systems, and● controls.

O.2.8 Perform LCC AnalysisPerform an LCC analysis for the centralchilled water plant based on the engineer-ing analysis. Compare it to the total LCCof the individual chilled water systems.The following items outline the procedureto follow in performing the simplifiedLCC analysis. Refer to section 0.3 for adetailed example,

O.2.8.1 Contact the equipment manufac-turers to obtain equipment (for example,cooling towers, chillers, pumps) pricingand chiller efficiencies at 100, 75, 50, and25 percent of full-load capacity.

O.2.8.2 Determine the mechanical roommodifications and associated costs requiredto meet ASHRAE Standard 15-1994 forthe selected chiller/refrigerant combina-tion. Refer to Appendix J, Application ofASHRAE Equipment Room Design Re-quirements, for equipment room modifica-tion requirements based on ASHRAE15-1992.

O.2.8.3 Calculate the annual energy costfor each of the chillers being consideredfor integration into a central plant. Referto the example in section 0.3 for guidancein calculating the annual energy cost foreach of the chillers.

O.2.9 Central Plant SelectionThe central chilled water plant is a candi-date for funding if it has a LCC less thanthe sum of the individual chilled watersystems.

O.3 Example of EvaluationThe following assumptions, figures, andtables provide the necessary information toassess the feasibility of clustering severalchillers into a single, central chilled waterplant. Table O-1, Existing Chiller Operat-ing Profiles, summarizes the existingchillers’ operating profiles during oneyear. Table O-2, Results from Replace orRetrofit Analysis, shows the results of theretrofit/replace for analysis completedprior to this calculation for the group ofchillers to be clustered together. TableO-3, Central Chilled Water Plant

O-4


Table O-1. Existing Chiller Operating Profiles

Annual Cooling Four-Point Load Profile

25% of Max 50% of Max 75% of Max Max Load

Unit Tons Hours Tons Hours Tons Hours Tons HoursNumber

Chiller 1 60 900 120 2,200 180 3,200 240 200

Chiller 2 70 1,000 140 2,100 210 3,000 280 100

Chiller 3 70 1,100 140 2,300 210 3,300 280 200

Chiller 4 80 1,200 160 2,400 240 2,600 320 50

Table O-2. Results from Replace or Retrofit Analysis

Present Value ofUnit Selected Alternative Life-Cycle Costa

Number

9110-1 Same Capacity Retrofit $710,500

9210-1 Same Efficiency Retrofit $771,700

9310-1 Same Efficiency Retrofit $771,700

9410-1 Drop-In Retrofit $853,400

Table O-3. Central Chilled Water Plant Operating Profile

Annual Cooling Load Profile for Central Plant

25% of Max 50% of Max 75% of Max Max Load

Tons Hours Tons Hours Tons Hours Tons Hours

250 1.500 500 2.500 750 2,000 1,000 1,000

O - 5


Operating Profile, summarizes the centralchilled water plant operating profile.

O.3.1 AssumptionsThe following assumptions were made inthe example shown in this appendix.

O.3.1.1 Average energy cost from theutilities data sheets is: $0.05 l/kWh.

O.3.1.2 The average maintenance savingswith the central plant will be approximate-ly $2000 annually.

O.3.1.3 The four chillers (Chillers 1, 2,3, and 4) listed in Table O-1 were identi-fied as a cluster of chillers with the poten-tial of incorporation into a central chilledwater plant. These units were chosen forconsideration of a central system becausetheir capacity-radius circles overlap (Ap-pendix H).

O.3.1.4 Table O-2 is an example ofresults expected from performing thechiller replace or retrofit analysis (Appen-dix M).

O.3.1.5 The annual cooling load profilefor the central system was computed elec-tronically by merging the load profiles forthe separate units. This procedure is dis-cussed in Appendix L. A four-point loadprofile is assumed for the central system asshown in Table O-3.

O.3.1.6 Develop a conceptual design forthe central system. The central plant chill-ers will be housed in a newly-constructedblock building. A primary/secondary

piping/pumping system will be used. Theprimary piping, connecting each user withthe central plant building, will be con-tained in a below-grade, concrete trench.New primary pumps will be purchased andhoused in the central plant building. Theexisting chilled water pumps and pipingwill remain in place and become the sec-ondary piping/pumping system. The exist-ing cooling towers and condenser waterpumps are assumed to be in good condi-tion and will be consolidated at the centralplant building and reused. Appendix Ncontains a discussion on chiller selectioncriteria. After reviewing this data, a750-ton electric centrifugal and a 250-tonelectric rotary screw chiller is selected forthe central plant. The rotary screw chillerwill operate during periods of loads lessthan 250 tons and greater than 750 tons.The centrifugal chiller will operate duringall other loads. This sequence of operationtakes advantage of the screw chiller’s su-perior operating efficiency at part-loadconditions and the centrifugal chiller’ssuperior operating efficiency at mid-to-fullloads.

O.3.1.7 Assume the following informa-tion for new equipment was obtained froma manufacturer.

CostEquipment Estimate Performance Data750-ton chiller $225,000 25 %: 1.00 kW/ton(electric 50%: 0.75 kW/toncentrifugal) 75%: 0.65 kW/ton

100%: 0.60 kW/ton

250-ton chiller $90,000 25%: 0.85 kW/ton(rotary screw) 50%: 0.75 kWlton

75%: 0.70 kWlton100 %: 0.75 kWlton

O-6


O.3.1.8 Estimate the initial cost of thecentral plant alternative.

Description750-ton chiller250-ton chillerPrimary pumpsControlsPiping & specialtiesBldg (30’ x 30’)Electrical serviceConcrete trenchLabor

CostEstimate Source$225,000 Manufacturer

90,000 Manufacturer10,000 Manufacturer15,000 Manufacturer90,000 Cost Estimate Guide110,000 Cost Estimate Guide50,000 Cost Estimate Guide160,000 Cost Estimate Guide290,000 Cost Estimate Guide

Total of Initial Costa $1,040,000

O.3.1.9 The following annual energy costassumptions were used in estimating theannual energy cost for the central plantalternative. The load profile is linear be-tween the four reference points, therefore:25% -

50% -

75% -

100%

The average load between O and250 tons is 125 tons and is servedentirely by the screw chiller. Onaverage, the screw chiller willoperate for 1,500 hours/year at50% of fill load (0.75 kW/ton).The average load between 250and 500 tons is 375 tons and isserved entirely by the centrifugalchiller. On average, the centrif-ugal chiller will operate for 2,500hours/year at 50% of full load(0.75 kW/ton).The average load between 500and 750 tons is 625 tons and isserved entirely by the centrifugalchiller. On average, the centrif-ugal chiller will operate for 2,000hours/year at 83% of full load(approx. 0.63 kW/ton).The average load between 750and 1,000 tons is 875 tons and is

served by both chillers. On aver-age, the centrifugal chiller willoperate for 1,000 hours/year at100% of full load (0.6 kW/ton).The screw chiller will operate for1,000 hours/year at 50% of fullload (0.75 kW/ton); simultaneous-ly for a total of 1,000 hrs.

O.3.1.10 The primary pumps will operatecontinuously during the cooling period.

O.3.2 Calculate Annual Energy Cost($ENERGY)

The first step in the evaluation is to calcu-late the annual energy cost for the pro-posed central chilled water plant. Thiscalculation is shown in Figure O-1,Calculate $ENERGY.

O.3.3 Present Value ($PV) FormulaA review of the present value formula ispresented prior to calculating the LCC ofa central plant. This analysis assumes a20-year study period and an expected lifeof all equipment of 20 years. Because theuseful life of all equipment is assumed tobe the same and only lasts through thestudy period, $REMAIN is zero. Becausenone of the capital equipment is replacedduring the study period, $REPLACE isalso zero. This formula is shown in Fig-ure O-2, Present Value ($PV) Formula.

O.3.4 Calculate the Present Value ofLCC for Central Plant ($PV)

The next step in assessing the potential ofa single, central chilled water plant is tocalculate the present value of the LCC forthe central plant. This calculation is shownin Figure O-3, Calculate $PV.

O-7


$ENERGY =

Where:$ENERGY =E F Fxx% =H R Sxx% =L O A Dx x % =$/kWh =k Wpump =H R Spump =

$ E N E R G Yplant =

$ E N E R G Yplant =

{(EFF25%)(HRS25%)(LOAD25%) + (EFF50%)(HRS50%)(LOAD50%) +EFF75%)(HRS75%)(LOAD75%) + (EFF100%)(HRS100%)(LOAD100%) +(kWpump)(HRSpump)} ($/kWh)

estimated annual energy cost for chiller operation ($/year)chiller efficiency at xx% of maximum capacity (kW/ton)hours of chiller operation at xx % of maximum capacity (hours/year)cooling load at xx% of maximum capacity (tons)average cost of electricity from the utilities data sheets ($/kWh)energy input to primary pumps = (40 hp)(0.746 kW/hp) = 29.8 kWhours of primary pump operation

{(0.75)(1,500)(125) + (0.75)(2,500)(375)+ (0.63)(2,000)(625) +((0.60)(1000)(750) + (0.75)(1,000)(125)) + (29.8)(7,000)} (0.051)$121,560

Figure O-1. Calculate $ENERGY

$PV =

Where:$PV =$INITIAL =

$REPLACE =(P/F,i%,N) =(P/A,i%,N) =i% =N =$ENERGY =$ M A I N T =$REMAIN =

$INITIAL + $REPLACE(P/F,i%,N) + ($ENERGY + $MAINT)(P/A,i%,N) -$REMAIN(P/F,i%,N)

present value of the life-cycle costs associated with a particular alternative ($)total initial cost of a particular alternative ($), including the cost for upgradingthe mechanical roomfuture replacement cost (assumed as zero ($))present value of a future cash flow at an interest rate of i% for N years1,2

present value of au annually-recurring cash flow at an interest rate of i % for N year S1,2

interest rate (discount rate) for federal energy conservation projects ( %)2

study period (years)estimated annual energy coat of chiller operation ($/year)annual maintenance costs ($)remaining value of equipment at the end of N years (assumed to be zero ($))


Figure O-2. Present Value ($PV) Formula

$PV = $INITIAL + ($ENERGY + $MAINT)(P/A,i%,N)

$ P VCentral Plant = $1,040,000 + ($121,560 + (-2000))(PA,4%,20)= $1,040,000 + $119,560(13.59)= $1,040,000 + $1,624,800

$PVCentral Plant = $2,664,800

Figure O-3. Calculate $PV

O-8


O.3.5 Compare LCCsCompare the LCC of the central plant withthe sum of the LCCs for separate selec-tions calculated in the retrofit versus re-place analysis (Appendix O). Select thealternative with the least LCC. For $PV ofthe existing individual chillers, refer toTable O-2. The summation to compare theLCC of individual systems with the LCCof a central plant is presented in Fig-ure O-4, LCC Comparison.

$ P VC h i l l e r 1= $ 7 1 0 , 5 0 0

$ P VC h i l l e r 2= $ 7 7 1 , 7 0 0

$ P VC h i l l e r 3= $ 7 7 1 , 7 0 0

$ P VC h i l l e r 4= $ 8 5 3 , 4 0 0

$ P VT o t a l I n d i v i d u a l S y s t e m s = $ 3 , 1 0 7 , 5 0 0

$ P VCentral Plant= $2,664,800

Figure O-4. LCC Comparison

O.3.6 Example ConclusionIn comparing total LCC of the individualunits with the LCC of a central chilledwater plant, the central plant is preferred.

O.4 List of MajorManufacturers

For further information presented in thisappendix, contact the following:


McQuay/Snyder General Corporation13600 Industrial Park Blvd.P.O. Box 1551Minneapolis, MN 55440(612) 553-5330



0-9 (0-10 Blank)


Appendix P — Heat Recovery Alternatives for Refrigerant Chillers

Appendix P — Heat Recovery Alternativesfor Refrigerant Chillers

ABSTRACT: This appendix provides guidelines for determining when heat recovery chillersmay be economically feasible. The decision to integrate heat recovery into a chilled water systemis based on comparing the life-cycle cost (LCC) of both alternatives.

P.1 Introduction

The purpose of this appendix is to opti-mize water chiller selection throughconsideration of heat recovery to convertwaste heat into useful energy. This analy-sis should be performed by an engineerfamiliar with building mechanical systemsand economic analyses.

P.1.1 ApplicabilityThis evaluation procedure is applicable tochiller installations where heat recoverychillers may be economically feasible.Before heat recovery can be considered aviable alternative, the following questionsmust first be answered: Is there heat torecover? Is there a use for the recoveredheat? A building is a likely candidate forheat recovery if it can pass this two-parttest. However, a building may not be agood candidate for heat recovery even if itdoes satisfy the two criteria. In-depthanalyses of the heating and cooling loadprofiles of the building, as well as theequipment used may be necessary. Typicaluses of recovered heat from chillers are:● reheat for process air conditioning

systems;● reheat for comfort air conditioning

systems;

● perimeter zone heating for comfort airconditioning systems;

● outdoor air preheating;● domestic hot water (HW) systems in

dormitories, dining halls, kitchens,shower rooms, and locker rooms;

● preheat for boiler make-up water sys-tems; and

● any hot water process or comfort load.

P.1.1.1 A cooling load must exist for heatrecovery systems to work. Buildings withsimultaneous heating and cooling loads arecandidates. Buildings with high internalloads are generally the best suited for thisapplication. This situation requires thechilled water system to operate year-round, increasing the feasibility of heatrecovery systems.

P.1.2 Advantages/DisadvantagesThe potential advantage of heat recovery isthe reduced energy cost achieved by recov-ering waste heat from the refrigerant loopwithin the chiller and converting it intouseful energy. A heat recovery chilleroperates at a lower efficiency (higherkW/ton) than a cooling-only chiller. Thetotal energy required for providing bothheating and cooling from a single piece ofequipment can be significantly less than

P-1

Appendix P — Heal Recovery Alternatives for Refrigerant Chillers

the energy required from two separatepieces of equipment.

P.1.2.1 It should be noted the initial costof a heat recovery chiller is higher than acooling-only chiller. This is due to theincreased refrigerant pressures and temper-atures required to elevate the condenserwater temperatures. Another item that addsto the cost of a heat recovery chiller is asecond condenser shell dedicated to theheat recovery loop.

P.1.2.2 Heat recovery systems may noteliminate the need for an auxiliary heatsource. This will depend on the requiredHW temperature. Due to the special con-struction requirements of a heat recoverychiller, manufacturers typically do notsupport the retrofit of an existing cooling-only chiller to a heat recovery chiller.Even if a retrofit is being performed on acooling-only chiller for the purpose ofconverting to a new refrigerant, it is notcost-effective to retrofit for the purpose ofadding heat recovery.

P.2 Analysis

This section provides guidance for deter-mining whether a heat recovery systemshould be incorporated into a potentialchilled water system. An end-user of therecovered heat must exist for the system tobe considered for evaluation. Each chilledwater system using heat recovery chillersthat has a lower LCC than the existing orproposed cooling-only chilled water systemshould be considered for implementation(see Appendix M, Evaluating Water Chill-ers for Replacement or Retrofit Potential,

or Appendix O, Assessing the Potential ofCentral Chilled Water Plants).

P.2.1 Obtain DataObtain data from equipment survey formsand either Appendix M or Appendix O foreach chilled water system to be evaluated.Determine the total cooling load on thechilled water system being considered forheat recovery. Further data gathering andevaluations of the building are typicallynecessary to determine its HW daily needsalong with the actual usage schedule. If agiven chilled water system is not a candi-date for the heat recovery evaluation, itmay still be a candidate for thermal energystorage.

P.2.2 Engineering AnalysisThe engineering analysis should consist ofcomparing the LCC analysis of the exist-ing or potential chilled water system to theproposed chilled water system which willuse heat recovery. The analysis shouldinclude engineering and construction costestimates, as determined in Appendix M orAppendix O, and additional costs for HWPumps, piping, equipment room modifica-tions, energy usage controls, and projectedannual maintenance costs for the proposedheat recovery system.

P.2.3 Perform LCCPerform an LCC estimate for the chilledwater system using heat recovery. Com-pare it to the total LCC of the existing orpotential chilled water systems. The fol-lowing items outline the procedure tofollow in performing the LCC analysis.

P.2.3.1 Equipment Pricing - Contact thechiller manufacturer to obtain the cost of

P-2


the proposed heat recovery chiller, heatrecovery rating (heat dissipation), andchiller performance efficiencies at 100, 75,50, and 25 percent of full loading. Gatherfurther cost information for all additionalor modified equipment to support the heatrecovery distribution system. Items forconsideration should include heatexchangers, pumps, and HW storagetanks.

P.2.3.2 Annual Energy Cost - The LCCanalysis will require calculating the annualenergy cost for each of the chillers beingconsidered for integration. The followingis a summary of methods described inAppendix L, Fundamentals of CoolingLoad and Energy Analysis, for estimatingannual energy costs. Calculate the annualenergy cost ($ENERGY) for each of thechillers. Depending on the number ofchillers in the system and the need for heatrecovery during cooling periods, performan individual calculation for each chiller.

P.2.3.3 Heat Reclaim Energy Savings -Determine the heat reclaim energy savings($BOILER-ENERGY). The amount ofusable reclaim energy savings will dependlargely on the compatibility of the hourlycooling load profile and the hourly heatingload profile as previously discussed inAppendix L. Typically, the cooling loadprofile will be estimated based on groupsof hours representing 25, 50, 75, and 100percent of part-load conditions. The annualheating load profile will need to be esti-mated in a similar fashion. The evaluatorwill need to group the annual hourly heat-ing demand into estimated groups of hoursmatching those of the chiller operation.Once the bins of operation have been

determined, contact the chiller manufactur-er and request the part-load heat reclaimperformance of each chiller being evaluate-d. Request the part-load performancesthat match the cooling only chiller. Oncethe amount of usable heat reclaim has beendetermined, the annual energy savings canbe determined.

P.2.3.4 Compute the present value ($PV)of the LCC. The $PV of the LCC is anequivalent cost, computed for the compari-son of mutually exclusive alternatives.

P.2.3.5 If the proposed heat recoverychilled water system has a lower LCC thanthe proposed chilled water system, the heatrecovery chilled water system should thenbe implemented.

P.3 Example of Evaluation

The following assumptions, figures, andtable provide the necessary information toassess whether a chiller slated for replace-ment is a candidate for a heat recoverychiller in lieu of a cooling-only chiller.

P.3.1 AssumptionsThe following assumptions have beenmade in developing a representative exam-ple of heat recovery chiller engineeringand LCC analyses.

P.3.1.1 Average energy cost from theutilities data sheet is: $0.051/kWh.

P.3.1.2 The chiller to be replaced is partof an existing central plant but is the onlychiller in the plant that is under consid-eration to be replaced. Total central plantpeak cooling load is 1,000 tons with a

P-3


constant year-round base cooling load of400 tons. The central plant was previouslydetermined to consist of two 500-ton chill-ers based on the LCC analysis. The heat isto be recovered 9 hours/day, 5 days/week(2,340 hours/year). The rest of the yearthe chiller will operate in a cooling-onlymode (6,420 hours/year). The proposedheat recovery chiller will provide the basecooling load of 400 tons. A nominal500-ton heat recovery chiller will be se-lected.

P.3.1.3 A year-round process heatingload of 5,300 Mbh (1,000 Btu/hour) ex-ists. This load is present 9 hours/day,5 days/week (2,340 hours/year). The heatreclaimed from the heat recovery chillerwill supply this load.

P.3.1.4 The existing heating source forthe process load is an electric HW boiler.The boiler provides the required 5,300Mbh load, 9 hours/day, 5 days/week.Electrical input to the boiler is 1,550 kW.

P.3.1.5 The heat recovery water loop andthe process heating water loop will beindependent circuits. Heat will be trans-ferred through a plate and frame type heatexchanger.

P.3.1.6 The present value ($PV) for thecooling only replacement chiller is:$1,510,000 (see Appendix M for the pro-cedure to determine the $PV for a coolingonly replacement chiller).

P.3.1.7 Estimate the initial cost of theheat recovery system.

CostDescription Es t imate Source500-ton H-R chiller $180,000 ManufacturerP u m p 1,400 ManufacturerHeat exchanger 4,200 ManufacturerControls 12,000 ManufacturerPiping & specialties 8,000 Cost Estimate GuideLabor 65,000 Cost Estimate Guide

Total of Initial Costs $270,600

P.3.2 Heat Recovery Chiller AnnualEnergy Cost ($ENERGY)

The first step in the evaluation is tocalculate the annual energy cost$ENRGYHeat Recovery for the proposed heatrecovery chiller. This calculation is shownin Figure P-1, Calculate $ENERGY.

P.3.3 Boiler Annual Energy CostsCalculate the energy costs to provide therequired process heat output with theexisting electric hot water boiler ($BOIL-ER-ENERGY). This calculation is theenergy dollars saved by providing therequired heat from the heat recovery chill-er instead of the electric boiler. FigureP-2, Calculate $BOILER-ENERGY, illus-trates this calculation.

P.3.4 Chiller and Boiler $PVFor comparison to the heat recovery op-tion, calculate the LCC for the cooling-only replacement chiller and HW boiler.This requires the calculation of the HWboiler $PV and adding it to the previouslydetermined chiller $PV. It is shown inFigure P-3, Calculate Chiller andBoiler $PV.

P-4

Appendix P – Heat Recovery Alternatives for Refrigerant Chillers

$ E N E R G YHeat Recovery = Σ {(EFF xx%)(HRS xx%)(LOAD xx%)} x ($/kWh)

Where:$ E N E R G YHeat Recovery = estimated annual energy cost for heat recovery chiller operation ($/year)EFFxx% = chiller efficiency at xx% of maximum capacity (kW/ton)HRS xx% = hours of chiller operation at xx% of maximum capacity (hours/year)LOAD xx% = cooling load at xx% of maximum capacity (tons)$/kWh = average cost of electricity from the utilities data sheds ($/kWh)

Since the chiller is operating at a constant base load of 400 tons year-round, referring toTable P-1, xx% =80%.

$ E N E R G YHeat Recovery = {(0.645)(6,420)(400) + (0.750)(2,340)(400)} X (0.051)$ E N E R G Y Heat Recovery = $120,280/year

Figure P-1. Calculate $ENERGY

$BOILER-ENERGY =

Where$BOILER-ENERGY =INPUT xx%

=HRSxx%

=$/kWh =

Σ Σ (lNPUTxx%)(HRSxx%)($/kWh)

annual energy cost to operate boiler ($/year)electrical input at xx% of maximum capacity (kW)hours of boiler operation at xx% of maximum capacity (hours/year)average cost of electricity from the utilities data sheets ($/kWh)

The boiler is operating at a constant load 9 hours/day, 5 days/week (2,340 hours/year).$BOILER-ENERGY = (1,550)(2,340)(0.051)$BOILER-ENERGY = $184,980/year

Figure P-2. Calculate $BOILER-ENERGY

$ P VReplacement = $BOILER-ENERGY(P/A,i%,N) + $PVChiller

= (184,980)(13.69) + 1,510,000= 2,532,400 + 1,510,000

$ P VReplacement = $4,042,400

Figure P-3. Calculate Chiller and Boiler $PV

P - 5


Table P-1. Heat Recovery Chiller, Energy Consumption Analysis

Heat Recovery Chiller Energy Consumption Analysis

Cooling-onlyCooling Capacity Operation (1) Heat Recovery Operation(2)

Heat Recovered% Load Tons kW kW/ton (Mbh) (3) kW kW/ton

100 500 328 0.656 - 0 - - 0 - - 0 -

90 450 291 0.647 6605 337 0.749

80 400 258 0.645 5875 300 0.750

70 350 226 0.646 5159 267 0.763

60 300 197 0.657 4451 236 0.787

50 250 169 0.676 3746 206 0.824

40 200 142 0.710 - 0 - - 0 - - 0 -

30 150 115 0.767 - 0 - - 0 - - 0 -

20 100 89 0.896 - 0 - - 0 - - 0 -

(1)

(2)

Water entering condenser shell at 29° C (85” F) at (3)maximum capacity. Entering condenser water tem-perature decreases as load decreases to a minimumtemperature of 21° C (70° F). (4)

Water entering heat recovery shell at 35° C (95° F)and maximum amount of heat is extracted. Leavingwater temperature from this shell is 40.4° C(104.8° F) at 450 tons and decreases to 38.5” C(101.3° F) at 250 tons.

Where "- 0 -" appears, no heat is available to berecovered.

Chat is based on 1500 gpm evaporator flow leavingthe evaporator at 7° C (44° F) and returning at12° C (54° F). Condenser flow rate and heat recov-ery flow rate is 1200 gpm each circuit.

P-6


P.3.5 Present Value ($PV) FormulaA review of the present value formula ispresented prior to its application with theheat recovery chiller LCC. This analysisassumes a 20-year study period and anexpected life of all equipment of 20 years.The useful life of all equipment is assumedto be the same and only lasts through thestudy period ($REMAIN is zero). None ofthe capital equipment is replaced duringthe study period ($REPLACE is zero).Maintenance for the heat recovery systemis assumed to be approximately $2,000more per year than that required for thechiller/boiler combination. Part of themaintenance cost is attributed to theplate and frame heat exchanger. A simpli-fied $PV formula is used to perform thecalculation. This formula is shown inFigure P-4, Present Value ($PV) Formula.

P.3.6 Calculate the Present Value ofLCC for Heat Recovery Chiller($PV)

Compute the present value of the life-cyclecosts for the heat recovery chiller ($PV).This calculation is shown in Figure P-5,Calculate $PV.

P.3.7 Comparison and SelectionCompare the LCC of the heat recoverychiller with the LCC for the cooling-onlychiller system. Select the alternative withthe least LCC.

$ P VR e p l a c e m e n t = $4,042,400$ P VH e a t R e c o v e r y

= $1,932,400Select the heat recovery chiller.

P.4 List of MajorManufacturers


McQuay/Snyder General Corporation13600 Industrial Park Blvd., Box 1551Minneapolis, MN 55440(612) 553-5330



P-7


$PV

Where:$PV$INITIAL

$REPLACE(P/F,i%,N)(P/A,i%,N)


=

==

===

=====

$INITIAL + $REPLACE(P/F,i%,N) + ($ENERGY + $MAINT)(P/A,i%,N) -$REMAIN(P/F,i%,N)

present value of the life-cycle costs associated with a particular alternative ($)total initial cost of a particular alternative ($), including the cost for upgradingthe mechanical roomfuture replacement cost, assumed as zero ($)present value of a future cash flow at an interest rate of i% for N years 1,2

present value of an annually recurring cash flow at an interest rate of i %for N years1,2

interest rate (discount rate) for federal energy conservation projects (%)’study period (years)estimated annual energy cost of chiller operation ($/year)annual maintenance costs ($)remaining value of equipment at the end of N years, assumed to be zero ($)


Figure P-4. Present Value ($PV) Formula

$PV = $INITIAL + ($ENERGY + $MAINT)(P/A,i%,N) - ($REMAIN)(P/F,i%,N)

For the heat recovery chiller system,$ P VH e a t R e c o v e r y

= $270,600 + ($120,280 + $2,000)(P/A,4%,20)= $270,600 + $122,280(13.59)= $270,600 + $1,661,800

$ P VH e a t R e c o v e r y= $1,932,400

Figure P-5. Calculate $PV

P-8

Appendix Q — Assessing the Potential of Thermal Energy Storage

Appendix Q — Assessing the Potential ofThermal Energy Storage

ABSTRACT: This appendix provides guidelines for determining when thermal energy storagesystems (TESS) may be an economically feasible alternative for integration into an existing orproposed chilled water system.

Q.1 Introduction

The purpose of this appendix is to provideguidelines for the consideration of TESSwithin the chiller selection process. TESSslower annual energy costs and allow areduction in the selected chiller’s capacity.This analysis should be performed by anengineer familiar with mechanical buildingsystems and economic analyses.

Q.1.1 Consideration of Advantages andDisadvantages

This evaluation procedure applies to exist-ing or proposed chilled water systems intowhich a TESS can be integrated. Thefeasibility of incorporating thermal energystorage will be determined by identifyingand analyzing various situations that mayfavor its success. Potential advantages ofintegrating a TESS into an existing orproposed chilled water system includelower initial costs and lower operatingcosts. A potential disadvantage is greaterspace requirements.

Q.1.1.1 Lower initial costs are possiblewhen the maximum cooling load is of ashort duration and the thermal storagerecovery time is of a long duration beforethe load returns. Examples are buildingswhich have relatively large loads for less

than six hours per day or only for a day ortwo per week. A relatively small chilledwater system can operate for the extendedduration and meet the storage needs.

Q.1.1.2 Lower operating costs are possi-ble because the production of the coolingstorage media (ice, chilled water, or abrine solution) occurs during off-peakhours. The local utility rates must bestructured such that off-peak rates are lessexpensive. This will also create a reduc-tion in demand costs.

Q.1.1.3 One potential disadvantage ofintegrating thermal storage into an existingor proposed chilled water system is thespace required for storage tanks. Tankstorage can be either above or belowgrade, but will require significant space.

Q.1.2 DefinitionsTerms used in this appendix are defined asfollows.

Q.1.2.1 Ton-hour - the amount of cooling(in tons) provided in a given amount oftime (in hours).

Examples: a chiller operating at100 tons for one hour would pro-duce the equivalent of 100 ton-hours. A chiller operating at 150

Q-1


tons for two hours and 50 tons forsix hours would produce an equiva-lent of 600 ton-hours.

Figure Q-1, Building Cooling Load Servedby Convetional System, provides a graph-ical representation of this concept.

Q.1.2.2 Off-peak - time period of the daywhen energy costs ($/kWh) are reduceddue to a lower demand for power from autility.

Q.1.2.3 on-peak - time period of the daywhen energy costs ($/kWh) are higher dueto a greater demand for power from autility.

Q.1.2.4 Demand charge - a charge as-sessed by an electric power company($/kW) for the highest electrical energyusage rate (kW).

Q.1.2.5 Charging - activity of creatingthe thermal energy to be stored.

Q.1.2.6 Discharging - activity of deplet-ing the thermal energy that was storedduring charging.

Q.1.2.7 Thermal efficiency of the storagetank - the rate of heat transfer acrosssurface of the storage tank expressedpercentage of energy lost in storage.

theas a

Q.2 System Descriptions

There are several different types of ther-mal storage systems. System types rangefrom chilled water storage to ice storage tophase change material storage (other thanwater and ice) as defined below.

Q.2.1 Chilled Water StorageChilled water storage is conceptually thesimplest type of thermal energy storage.The storage tanks can either be locatedabove or below grade. The storage volumeis proportional to the required thermalstorage capacity and inversely proportionalto the chilled water supply-to-return tem-perature difference. For cost-effectiveness,the storage system should be designed witha -7° C (20° F) AT between the supplyand return water temperatures. As a rule,chillers should produce 4° C (40° F) waterand coils should, at maximum load, beable to return water at a minimum of16° C (60° F).

Q.2.1.1 The following equation can beused as a rule of thumb to determine therequired tank size:

Volume = (Capacity x 1000) / ∆ TWhere:

Volume is in gallons,Capacity is in ton-hours,∆ ∆ T is in °C, and1000 is a factor which incorpo-

rates the specific heat ofwater and an 8 percentefficient storage tank.

Q.2.1.2 An installation strategy that isunique to chilled water storage is integrat-ing the chilled water storage tank with thefire water storage tank. In doing so, thecapital costs for storage is essentially cutby 50 percent.

Q.2.2 Ice StorageIce storage uses thermal energy which canbe stored as the latent heat of fusion ofice. Latent heat of fusion is the heat re-quired to change between a solid and a

Q-2


Conventional Cooling System

Figure Q-1. Building Cooling Load Served by Conventional System

Q-3


liquid phase. Water, which has the highestlatent heat of fusion of all common materi-als, is 144 Btu/lbm. Because of this highlatent heat of fusion, the required tank sizefor ice storage systems is approximately 15to 20 percent of that required for chilledwater storage.

Q.2.2.1 There are several types of icestorage systems available. Most of thesesystems are available as off-the-shelf typecomponents. In some instances, a storagetank may need to be field erected or cus-tom made. The reduced discharge tempera-ture required during charging poses apenalty on the operating efficiency of achiller. Therefore, it is the required capac-ity during charging, not the required ca-pacity during normal operation, that setsthe chiller size. For a typical ice storagesystem, the nominal chiller size requiredwill be approximately 50 to 80 percentlarger than for a chilled water storagesystem. For example, in Figure Q-2,Building Cooling Load Served by PartialStorage System, a 250-ton output is re-quired from the chiller. A nominal chillersize of 375 to 450 tons will be required toachieve the 250-ton output needed duringice building. Table Q-1, Equipment Costs,lists the approximate costs of major systemcomponents. The costs are based on therate of cooling required, not the nominalchiller size. For example, the equipmentcost for a chiller able to operate at 250tons during ice building will be:(250 tons) x ($650/ton) = $162,500.The actual chiller size will be in the rangeof 375 tons to 450 tons. It is advisable toseek assistance from a manufacturer’srepresentative when selecting a chiller forice building capabilities.

Table Q-1. Equipment CostsThermal

Chiller Storage(1)

System $/Ton $/Ton-Hr

ChilledWater(1) 350 65

Ice-on-Coil 650 65

Ice-in-Container 650 60

Solid IceBrine Coil 650 60

IceHarvester 650 50

EutecticSalts 350 95

(1) Based on a storage capacity of approximately5,000 ton-hours, chilled water storage sys-tems typically involve field erected storagetanks. Therefore, labor is included, but costsfor site preparation is not included.

Q.2.2.2 The most common ice storagemethod is the ice-on-coil system. Thissystem generates ice by submerging refrig-erant or brine coils in a tank of water.Water is frozen on the face of the coil to athickness of approximately 2.5 inches. Theice is stored until needed. Return water isthen chilled as it passes through the ice,supplementing or replacing chiller output.This system uses two independent pipingsystems: one containing the low-tempera-ture brine solution, the other containingthe chilled water and ice-water mixture inthe storage tank. These two fluids do notmix. Additionally, it may be desirable todesign the chilled water loop as aprimary/secondary distribution system.

Q-4


Partial Storage System

Hour of Day

Figure Q-2. Building Cooling Load Served by Partial Storage System

Q-5


Q.2.2.3 The ice-in-containers methoduses high-density polyethylene containersfilled with deionized water and an icenucleating agent. The containers are com-mercially available in either spherical orrectangular configurations. These contain-ers are placed in storage tanks where acooled (-4° C to -3° C (24° F to 26° F))brine solution is pumped through the tank,freezing the containers. During discharge,the return water is chilled as it is pumpedthrough the tank. For this strategy, asingle closed piping system is all that isrequired. This piping system can be eithera single piping loop or a primary/second-ary piping arrangement. Unlike the ice-on-coil system, the low temperature fluid andthe high temperature fluid are the same. Ifit is undesirable to have a brine solutionpumped throughout a system, a heat ex-changer can be installed between theprimary and secondary loop.

Q.2.2.4 Commercially available solid icebrine coils are a method of storage whereplastic mats with integral brine coils areplaced inside a cylindrical tank. Thesecoils occupy approximately ten percent ofthe tank volume and water occupies ap-proximately 80 percent. The remainingten percent of the tank volume allows forexpansion during the charging cycle. Abrine solution (-4° C to -3° C) from achiller is circulated through the coils tofreeze the water during the charging cycle.During the discharging cycle (typicallywhen the chiller is not operating), thebrine solution is returned from the end-users and pumped through the brine coilsand is re-chilled. The piping arrangementsfor the solid ice brine coils are similar tothe ice-in-containers.

Q.2.2.5 Ice harvesting is a method ofthermal storage where ice is formed on theface of evaporator coils at a thickness of0.25 to 0.40 inches. The evaporator coilscontain refrigerant at -4° C to -3° C(24° F to 26° F) and are located above anice and water bath storage tank. Water issprayed onto the coils until a predeter-mined thickness of ice is formed. The iceis then discharged from the coils anddropped into a storage tank until a prede-termined level of ice is formed. The stor-age tank is an integral part of the iceharvester machine. The tank will contain a0° C (32° F) ice and water mixture. Thissystem requires an independent closed looppiping circuit containing the refrigerant. Aseparate open piping circuit will distributewater from the storage tank to the individ-ual users. The chilled water in this loop iscirculated directly through the ice andwater mixture in the storage tank. Thepiping circuit serving the end-users (0° C(32° F) water) can be installed as a pri-mary/secondary piping system if desired.

Q.2.3 Phase Change MaterialsPhase change materials, such as a eutecticsalt solution, are commonly used for coldstorage applications because of their abilityto melt and freeze at temperatures of 8° C(47° F). Eutectic salt is a mixture of inor-ganic salts, water, and nucleating andstabilizing agents. The eutectic salt solu-tion is encapsulated in a high-densitypolyethylene container. These containersare rectangular in shape and measureapproximately 24" x 8" x 1-3/4" and areself-stacking. Because of their 8° C(47° F) freezing point, conventionalchilled water temperatures of 6° C (42° F)can be used. This allows for increased

Q-6


flexibility in chiller selection and bettermechanical efficiency during charging.This system is very similar to the ice-in-containers method, except the fluid in thecontainer is different and low water tem-peratures are not required. The pipingsystem for this method is the same as theice-in-containers system. The volumerequired for eutectic salts is approximately30 percent of that required for chilledwater storage.

Q.2.4 Equipment CostsTable Q-1 provides estimated costs of ther-mal storage systems based on a systemstorage capacity of approximately 5,000ton-hours. Except for the chilled waterstorage system, costs are for materialsonly and do not include installation, pip-ing, and pump costs. The cost per ton-hour of storage space varies inversely withthe storage requirements. This is especiallytrue for the chilled water storage systems.Exercise caution when using the $65/ton-hour value for chilled water storage sys-tems. For example, a 25,000 ton-hourchilled water storage tank would cost about$35/ton-hour. Installation costs will varydepending whether the tank is above gradeor below grade. Costs for the glycol orbrine solution in the low temperaturesystems (ice storage) will vary greatlydepending on piping arrangements.

Q.2.5 Operating StrategiesThe following are descriptions of threethermal storage system operating strate-gies. The physical size of the storagesystem will depend on:● the method used (for example, water or

ice storage),● building cooling load profile, and

● the operating strategy chosen for shift-ing the electrical load.

The example used through the rest of thisappendix will be based on a building witha cooling load profile requiring 6,000 ton-hours of cooling capacity (shown in Fig-ure Q-1). A conventional chiller systemserving this load would require an 800-tonchiller operating at various percentages offull capacity for 13 hours per day. Thebuilding cooling load and chiller operatingprofiles are identical.

Q.2.5.1 Partial storage is a strategywhere sufficient thermal energy is storedduring the off-peak hours to provide a flatenergy usage curve from the chiller duringa twenty-four hour period. Based on thesame building cooling load profile of Fig-ure Q-1, the building cooling load andchiller operating profiles for the partialstorage strategy are shown in Figure Q-2.Of the total 6,000 ton-hours required,3,050 are provided from the stored thermalenergy. This strategy imposes a constant250-ton load on the system. An advantageof partial storage is that it requires thesmallest chiller of the three operatingstrategies, as well as that required for aconventional cooling system. A disadvan-tage is the chiller continues to operateduring the on-peak hours.

Q.2.5.2 Demand limited storage is astrategy where sufficient thermal energy isstored during the off-peak hours to preventthe chiller from operating during the on-peak hours. Figure Q-3, Building CoolingLoad Served by Demand Limited StorageSystem, illustrates this operating strategyusing the same 6,000 ton-hour per dayload. Of the total 6,000 ton-hours

Q-7


Demand Limited Storage System

Hour of Day

Figure Q-3. Building Cooling Load Served by Demand Ltited Storage System

Q-8


required, 4,250 ton-hours are provided bythe stored thermal energy. This strategyimposes a 333-ton load on the system for18 hours per day. An advantage of demandlimited storage is the chiller does notoperate during the on-peak hours, therebyreducing electrical demand cost. A disad-vantage is it requires a larger chiller andmore thermal energy storage space than apartial storage system (4,250 ton-hoursversus 3,050 ton-hours).

Q.2.5.3 Full storage is a strategy wheresufficient thermal energy is stored duringperiods of no load to prevent the chillerfrom operating during periods of load.Using the 6,000 ton-hour per day loadprofile, the chiller operating profile isshown in Figure Q-4, Building CoolingLoad Served by Full Storage System. Allcooling ton-hours are provided by thestored thermal energy. This strategy im-poses a 545-ton load on the system for 11hours per day. An advantage of full stor-age is the chiller only operates during theevening hours when building energy usageis typically less. A disadvantage is this ar-rangement requires a larger chiller andmore energy storage space than the othertwo strategies. For a chilled water storagesystem, this strategy will allow a smallerchiller than a conventional chiller system.For an ice storage system, chiller size maybe the same, or even larger, than a con-ventional chiller system.

Q.3 Selection Procedure

This section provides guidance for deter-mining whether a TESS can be incorporat-ed into an existing or new chilled watersystem and selecting the system type. The

following paragraphs briefly describe thesteps required to perform this analysis.Equations and a detailed example areprovided in section Q.4.

Q.3.1 Assess ConditionsBefore thermal storage can be consideredas an alternative, two basic conditionsmust exist:1) the average building cooling load

profile is cyclical, with periods of highload occurring during the day, and lowload occurring during the night, and

2) the utility company assesses a demandcharge as well as significantly differenton-peak and off-peak rates.

Q.3.2 Obtain DataObtain a completed copy of the AC/REquipment Survey Form for water chillers(Appendix H, AC/R Equipment SurveyGuide and Equipment Data CollectionSurvey Forms), a cooling load analysis ofthe building (Appendix L, Fundamentals ofCooling Load and Energy Analysis), utilityrates and rate schedules (Appendix H), andany replacement analyses so far performed(Appendix M, Evaluating Water Chillersfor Replacement or Retrofit Potential, orAppendix O, Assessing the Potential ofCentral Chilled Water Plants).

Q.3.3 Determine the Peak HourlyCooling Load Profile

To accurately size the TESS, the loadprofile should reflect the 24-hour coolingrequirements for the peak cooling day. Thepeak cooling day will typically be the daythat requires the greatest number of ton-hours. This information can be graphicallyrepresented by aligning the rate of cooling(tons) along the ordinate, and the hour of

Q-9


Full Storage System

Hour of Day

Figure Q-4. Building Cooling Load Served by Full Storage System

Q-10


day along the abscissa of a Cartesiancoordinate system as illustrated in Fig-ure Q-1. This graph will clearly show thetwenty-four hour building load profile andallow the evaluator to determine the on-peak and off-peak ton-hours. Repeat thisprocedure for both peak and typical daysfor all months of the cooling season (seesection Q.4).

Q.3.4 Determine the AnnualEnergy Cost

The next step is to determine the annualenergy cost of the conventional chilledwater system. A simplified approach todetermining the annual energy cost fol-lows.1)

2)

3)

The electrical utility rate structure mustbe thoroughly reviewed. If the electri-cal utility rates are divided into con-sumption charges and demand charges,calculate the demand charge. Demandcharges are based on the highest re-corded demand for electricity, mea-sured over a brief period, usually 1 to15 minutes. Compute the demandcharge for each monthly peak loadprofile by multiplying the peak demand(kW) by the demand charge ($/kW).If a non-racheting billing rate structureis used for demand charges (demandcharge is based on peak kW eachmonth), repeat the peak demand chargecalculation for each cooling month andadd to determine the annual cost.If demand charges are based on aracheting billing structure (demandcharge is based on the peak kW in thepast 12 months), use the greatest de-mand charge in the past year and mul-tiply by the number of cooling monthsto determine the annual demand cost.

4)

5)

6)

Compute the average monthly baseenergy usage cost as follows. Multiplythe energy used (ton-hours) during theoff-peak hours (the area under thechiller operation curve bound by thestart and stop time of the off-peakelectrical rates) by the off-peak electri-cal rates ($/kWh) and chiller efficiency(kW/ton). Perform a similar calculationfor the on-peak period. Repeat calcula-tions for each month in which coolingis required. Add up the usage costsfrom each month to get a yearly baseenergy-use cost ($).Add the annual base energy-use costsand the annual demand costs to get thetotal annual energy cost.Using the load profile for the threepossible thermal storage operations(partial, demand limited, and fullstorage), evaluate the energy cost asdescribed above.

Q.3.5 Compute Life-Cycle Costs (LCC)and Compare Alternatives

Once the annual cooling energy costs havebeen calculated, the initial cost, mainte-nance cost, replacement cost, and remain-ing value should be evaluated on a LCCmethod to determine the best alternative.The optimum thermal storage systemminimize the LCC.

Q.4 Example of Evaluation

will

The following assumptions, figures, andtables provide a method of determining ifa thermal storage system is economicallyviable. Refer to Figure Q-1 for a graphicalpresentation of the yearly peak coolingload profile used in this illustration. Thisexample compares a conventional chiller

Q-11


system to a solid ice brine coil thermalstorage system operating at each of thethree operating strategies described.

Q.4.1 AssumptionsThis analysis procedure assumes:●

●

●

●

●

●

On-peak hours:11:00 a.m. to 5:00 p.m.Off-peak hours:12:00 midnight to 11:00 a.m. and5:00 p.m. to 12:00 midnightOn-peak demand charge:($DEMANDon) = $8.72/kWOn-peak base energy charge:($BASEon) = $0.0607/kWhOff-peak base energy charge:($BASEoff) = $0.0486/kWhRate Structure: non-racheting (demandcharge is reset each month to highestdemand occurring during the month)

Q.4.2 Calculate Annual Demand Cost($DEMAND)

The first step in assessing the potential ofthermal energy storage is to calculateannual demand cost, This is shown inFigure Q-5, Calculate $DEMAND. Thiscalculation is repeated for each month andfor each storage system strategy.

Q.4.3 Calculate Annual Base EnergyCosts ($BASE)

The second step is to calculate annual baseenergy costs. This calculation is shown inFigure Q-6, Calculate $BASE. This calcu-lation is repeated for each type of storagesystem strategy.

Q.4.4 Calculate Annual Energy Costs($ENERGY)

The third step is calculating the annualenergy costs. This calculation, shown inFigure Q-7, Calculate $ENERGY, is

performed for each storage system strate-gy.

Q.4.5 Determine Maximum CoolingRate Thermal Storage Required

Referring to Figures Q-1, Q-2, Q-3, andQ-4, the maximum rate of cooling (tons)required and maximum amount of thermalstorage (ton-hours) required are as follows:

Rate of Required

System Cooling StorageConventional 800 tons 0 ton-hrPartial storage 250 tons 3,050 ton-hrDemand limited 333 tons 4,250 ton-hrstorage

Full storage 545 tons 6,000 ton-hr

Q.4.6 Determine Capital EquipmentCosts ($CAPITAL) for EachSystem

Step five requires the determination of thecapital equipment costs for each system.Figure Q-8, Calculate $CAPITAL, illus-trates this calculation. Table Q-1 providesthe budget pricing numbers.

Q.4.7 Determine Installation Costs($INSTALL) for Each System

Refer to published cost-estimating guides,recent in-house projects, and equipmentvendors for guidelines. In this example,the following determination was made.

$INSTALL conventional = $210,000$ I N S T A L part ial = $213,400$INSTALL demand = $289,800$INSTALL full = $445,700

Q.4.8 Determine Initial Costs($NITIAL) for Each System

Step seven in the assessment is calculatingthe initial cost. Figure Q-9, Calculate$INITIAL, illustrates this calculation andprovides the costs for the conventionalsystem and each storage system strategy.

Q-12


$DEMAND = ( T O N Son=peak ) ( E F F# # %) ( $ D E M A N Do n)

Where:E F F# # %

= chiller efficiency at ##% of maximum capacity (kW/ton)(refer to Table Q-2)

For the conventional chiller system (refer to Table Q-3):$ D E M A N Dconventional = ((350)(1.06) + (600)(1. 18) + (750)(1.33) + (800)(1.33) + (650)(1.33) +

(300)(0.93))kW x (8.72)$/kW$DEMAND conventional

= $37,360

Repeating for each type of storage system strategy (refer to Tables Q-4, Q-5, and Q-6):$DEMAND partial

= $10,400 for partial storage system$DEMAND demand

= $0 for demand limited storage system (shifted to off-peak hours)$DEMAND full

= $0 for full storage system (shifted to off-peak hours)

Figure Q-5. Calculate $DEMAND

Table (O-2. Chiller Efficiencies at Various Operating Points

System DescriptionChiller Efficiency - kW/Ton

and Ice

Chiller Size 20% 40% 60% 80% 100% Making

Conventional System -800 Tons Maximum Load 1.00 0.93 1.06 1.18 1.33 n/a

Air-cooled Rotary Screw

Partial Storage System -250 Tons Maximum Load 1.01 0.95 1.08 1.20 1.35 1.51


Demand Limited Storage System -333 Tons Maximum Load 1.01 0.94 1.07 1.19 1.34 1.51


Full Storage System -545 Tons Maximum Load 1.00 0.93 1.06 1.18 1.33 1.51


Q - 1 3


Table Q-3. Chiller Operating Schedule for Conventional Chiller System

800-Ton Peak Load (Nominal 800-Ton Chiller) Values for Monthly Peak Day

Monthly Peak On-Peak Ton-Hours Off-Peak Ton-Hours

Month Tons kW 20% 40% 60% 80% 100% 20%

May 350 357 0 1770 0 0 0 610

June 600 648 0 0 900 2140 0 335

July 750 998 0 0 0 1730 2050 230

Aug 800 1064 0 0 0 1200 2850 250

Sept 650 865 0 0 940 1670 650 360

Ott 300 294 0 0 1520 0 0 590

Totals 0 1770 3360 6740 5550 2375

40% 60% 80% 100%

220 0 0 0

750 375 0 0

460 1130 0 0

500 700 500 0

770 410 0 0

190 0 0 0

2890 2615 500 0

Table Q-4. Chiller Operating Schedule for Partial Storage System

250-Ton Peak Load (Nominal 375-Ton Chiller) Value for Monthly Peak Day

Monthly Peak(During On-Peak Hours) Off-Peak Ton-Hours Total

On-Peak Thermal Storage Thermal Storage Peak DayMonth Tons kW Ton-hours Charging Discharging Ton-Hours

May 108 106 650 1335 615 2600

June 188 192 1125 2290 1085 4500

July 233 252 1400 2855 1345 5600

Aug 250 270 1500 3050 1450 6000

Sept 200 204 1200 2440 1160 4800

Oct 96 94 575 1140 585 2300

Q-14


Table Q-5. Chiller Operating Schedule for Demand Limited Storage System

233-Ton Peak load (Nominal 500-Ton Chiller) Values for Monthly Peak Day

Monthly Peak(During On-Peak Hours) Off-Peak Ton-Hours

TotalOn-Peak Thermal Storage Thermal Storage Peak Day

Month Tons kW Ton-Hours Charging Discharging Ton-Hours

May o 0 0 1850 750 2600

June o 0 0 3185 1315 4500

July o 0 0 3975 1625 5600

Aug o 0 0 4250 1750 6000

Sept o 0 0 3410 1360 4800

Ott o 0 0 1610 690 2300

Table Q-6. Chiller Operating Schedule for Full Storage System

545-Ton Peak Load (Nominal 820-Ton Chiller) Values for Monthly Peak Day

Monthly Peak(During On-Peak Hours) O f f - P e a k T o n - H o u r s T o t a l

Peak DayThermal Storage Thermal Storage

Ton-HoursOn-Peak

Month Tons kW Charging Discharging Ton-Hours

May 0 0 0 2600 0 2600

June 0 0 0 4500 0 4500

July 0 0 0 5600 0 5600

Aug 0 0 0 6000 0 6000

Sept 0 0 0 4800 0 4800

Oct 0 0 0 2300 0 2300

Q-15


$BASE =

Where:TONHRS ##

=

EFF##%=

A V G T O N H R S =

P E A K T O N H R S =

DAYS =

{{ Σ ((TONHRS)##(EFF)##%) X ($BASEon)}on-peak + { Σ ((TONHRS)##(EFF)##%) x($BASEoff)}off-peak } x Σ ((AVGTONHRS/PEAKTONHRS) x DAYS)

ton-hours at specific efficiency ratings(refer to Tables Q-3, Q-4, Q-5, Q-6)chiller efficiency at ##% of maximum capacity (kW/ton)(refer to Table Q-2)Average number of ton-hours in a day(refer to Table Q-7 for this example)Peak number of ton-hours occurring one day during the month(refer to Table Q-7 for this example)days in the month

For the conventional chiller system (refer to Table Q-3):$ B A S Ec o n v e n t i o n a l = {((1770)(0.93) + (3360)(1.06) + (6740)(1.18) + (5550)( 1.33))kWh x

(0.0607)$/kWh + ((2375)(1.00) + (2890)(0.93) + (2615)(1.06) +(500)( 1.18))kWh x (0.0486)$k/wh} X {((1800 + 3200 + 3900 + 4200 +3400 + 1600)/(2600 + 4500 + 5600 + 6000 + 4800 + 2300)) X

(31 + 30 + 31 + 31 + 30 +31)}$ B A S Ec o n v e n t i o n a l = $213,810

Repeating for each type of storage system strategy (refer to Tables Q-4, Q-5, and Q-6):$ B A S Ep a r t i a l

= $223,700 for partial storage system$ B A S Ed e m a n d

= $217,510 for demand limited storage system$ B A S Ef u l l = $244,360 for full storage system

Figure Q-6. Calculate $BASE

Table O-7. Ton-Hour Usage Summarization

Peak Day Average Day Days In MonthlyMonth Ton-Hours Ton-Hours Month Ton-Hours

May 2600 1800 31

June 4500 3200 30

July 5600 3900 31

August 6000 4200 31

September 4800 3400 30

October 2300 1600 31

55,800

96,000

120.900

130,200

102,OOO

49,600

Q-16


$ENERGY = $DEMAND + $BASE

For the conventional chiller system$ENERGYconventional $ 2 1 3 , 8 1 0 = $ 2 5 1 , 1 7 0

R e p e a t i n g f o r e a c h t y p e $ENERGY partial

= $234,100 for partial storage system$ENERGY demand = $217,510 for demand limited storage system$ENERGY full = $244,360 for full storage system

Figure Q-7. Calculate $ENERGY

For the conventional chiller system$ C A P I T A L convent ional 800 tons)(350 $/ton) + (0 ton-hours)(0 $/ton-hour)$ C A P I T A L convent ional = $280,000

Repeating for each type of storage system strategy:$ C A P I T A L part ial = $345,500 for partial storage system$ C A P I T A L d e m a n d = $471,450 for demand limited storage system$ C A P I T A L f u l l = $714,250 for full storage system

Figure Q-8. Calculate $CAPITAL

$INITIAL = $CAPITAL + $INSTALL

For the conventional chiller system$ I N I T I A L convent ional = $280,000+ $210,000= $490,000

Repeating for each type of storage system strategy:

$INITIAL partial= $ 558,900

$INITIAL demand= $ 761,250

$INITIAL full = $1,159,950

Figure Q-9. Calculate $INITIAL

Q-17


$PV

Where$PV$INITIAL$REPLACE(P/F,i%,N)(P/A,i%,N)


=

=====

=====

$INITIAL + $REPLACE(T/F,i%,N) + ($ENERGY + $MAINT)(P/A,i%,N) -$REMAIN(WF,%,N)

present value of the life-cycle costs associated with a particular alternative ($)total initial cost of a particular alternative ($)future replacement cost (assumed as zero)present value of a future cash flow at an interest rate of i% for N years1,2

present value of an annually-recurring cash flow at an interest rate of i%for N years1,2

interest rate (discount rate) for federal energy conservation projects (%7study period (years)annual energy costs ($)annual maintenance costs ($)remaining value of equipment at the end of X years (assumed to be zero)


Figure Q-10. Present Value ($PV) Formula

$PV = $INITIAL + ($ENERGY + $MAINT)(P/A,i%,N)

For the conventional chiller system$ P Vc o m m e r c i a l = 490,000 +((251,170 + 1600) x (P/A,4,20))

= 490,000 + (252,770X 13.59)$ P Vc o m m e r c i a l = $3,925,100

Repeating for each type of storage system alternative:$ P Vp a r t i a l

= $3,774,300$ P Vd e m a n d = $3,764,800$ P Vf u l l = $4,551,500

Figure Q-n. Calculate $PV

Q.4.9 Determine Annual MaintenanceCosts ($MAINT) for Each System

For this example, the following determina-tion of annual maintenance costs for eachsystem were made.

$ M A I N Tc o n v e n t i o n a l = $ 1 , 6 0 0$ M A I N T p a r t i a l

= $ 2 , 5 0 0$ M A I N Td e m a n d = $3,500$ M A I N T f u l l = $ 5 , 2 0 0

Q.4.10 Present Value ($PV)A review of the present value formula ispresented prior to calculating the LCC ofthe alternatives. This analysis assumes a20-year study period and an expected lifeof all equipment of 20 years. The useful

Q-18

life of all equipment is assumed to be thesame and only last through the study peri-od, thus $REMAIN is zero. None of thecapital equipment is replaced during thestudy period, thus $REPLACE is zero.This PV formula is shown in Figure Q-10,Present Value ($PV) Formula.

Q.4.11 Calculate the Present Value ofLCC for Each System ($PV)

The $PV is an equivalent cost, computedfor the comparison of mutually exclusivealternatives. Figure Q-11, Calculate $PV,illustrates this calculation.


Q.4.12 DeterminationBased on the calculations and determina-tions provided in the example, the systemselected would be the demand limitedstorage system.

Q.5 List of MajorManufacturers

Q.5.1 Ice Harvester MethodBaltimore Aircoil CompanyP.O. Box 7322Baltimore, MD 21227(410) 799-6200

Turbo Refrigeration Company1815 Shady Oaks DriveP.O. Box 396Denton, TX 76205(817) 387-4301

Q.5.2 Solid Ice Brine Coil MethodCalmac Manufacturing Corp.101 W. Sheffield Ave.Englewood, NJ 07631(201) 569-0420

Q.5.3 Chilled Water Storage MethodChicago Bridge & Iron Technical ServicesCompany1501 North Division StreetPlainfield, IL 60544(815) 439-6000

Q.5.4 Ice-on-Coil MethodSnyder General Corporation13600 Industrial Park Blvd.P.O. Box 1551Minneapolis, MN 55440(612) 553-5330

Q.5.5 Eutectic Salts MethodTransphase Systems, Incorporated15572 Computer LaneHuntington Beach, CA 92649(714) 893-3920

Q.5.6 Ice-in-Containers MethodYork International CorporationP.O. Box 1592York, PA 17405(717) 771-7890

Q-19 (Q-20 Blank)


Appendix R — Glossary of Terms, Definitions, and Bibliography

Appendix R — Glossary of Terms, Definitions,and Bibliography

R. 1 Glossary of Terms andDefinitions

A/C: air conditioning

ACGIH: American Conference of Gov-ernment and Industrial Hygienists

AC/R: air-conditioning and refrigeration

AEL: allowable or acceptable exposurelimits

AFB: Air Force Base

AF/CE: Air Force Civil Engineers

AFCESA: Air Force Civil EngineerSupport Agency

ALR: actual leak rate

ANSI: American National Standards Insti-tute

APLV: Application Part-Load Value. Asingle kW/ton value which modifies theIPLV for the chilled and condenser watersupply temperatures required in a specificapplication. The same IPLV schedule foroperational hours is used in producing thisvalue.

Appliance: Any device which contains aClass I or Class II chlorofluorocarbon as arefrigerant and is used for household orcommercial purposes (for example; airconditioner, refrigerator, chiller, orfreezer).

ARI: Air-Conditioning and RefrigerationInstitute or American Refrigeration Insti-tute

ASHRAE: American Society of Heating,Refrigerating and Air-Conditioning Engi-neers

ASME: American Society of MechanicalEngineers

BAS: building automation system

BCE: base civil engineer

BLCC: building life-cycle cost

BRMP: Base Refrigerant ManagementProgram

Btu: British Thermal Unit. A unit ofheat; the heat required to raise the tem-perature of one pound of water, at itsmaximum density, one degree Fahrenheit:also, the heat to be removed in coolingone pound of water one degree Fahrenheit.

Btu/hr: British thermal unit per hour

CAA: Clean Air Act

CAAA: Clean Air Act Amendments

CE: civil engineer

Central Chilled Water Plant: Multiplechilled water systems combined and servedfrom a single piping network.

CERL: U.S. Army Construction Engi-neering Research Laboratory

CerTest: U.S. Air Force-administeredcertification test

CFC: chlorofluorocarbon

Challenging Alternative: Proposed opti-mization of the defending alternative with

R-1


the purpose of trying to establish an alter-native that is more energy efficient with alower LCC.

Chilled Water System: also ChillerSystem. One or more chillers that serve asingle piping network.

CLTD: cooling load temperature differ-ence. An ASHRAE method that simplifiesthe solar heat gain calculation for a cool-ing load on a building. It substitutes a one-step conduction calculation for the solarheat transfer through walls, roofs, andglass using an equivalent temperaturedifference.

Cluster: Individual chilled water systemswithin close proximity of each other thatmay be considered for incorporation into acentral chilled water plant.

Commercial Refrigeration: Refrigerationappliances used in retail food and coldstorage warehouse sectors.

COP: coefficient of performance

CR: consumption rate. The annual rate atwhich a refrigerant is being lost to leaksand emissions, typically given in poundsper year.

CRR: critical refrigerant reserve. Thesingle, largest charge, in pounds, for eachrefrigerant used at an AFB.

CWE: current working estimate

DBMA: Defense Business MaintenanceArea

Defending Alternative: Lowest LCCchiller alternative from the previousanalysis.

Demand Charge: A charge assessed by autility for the largest amount of powerused during a specified period of time.

R - 2

DERA: Defense Environmental Restora-tion Account

Disposal: The process leading to thedisassembly of any appliance for re-use ofits component parts; the disassembly ofany appliance for discharge, deposit, dum-ping or placing of its discarded componentparts into or on any land or water; thedischarge, deposit, dumping or placing ofany discarded appliance into any land orwater.

DLA:

DoD:

DPB:

Defense Logistics Agency

Department of Defense

discounted payback

EC: environmental compliance

ECIP: Energy Conservation InvestmentProgram

EEL: emergency exposure limit. Theconcentration from which escape is feasi-ble without any irreversible effects onhealth in an emergency situation whererecurrence is expected to be rare in anindividual’s lifetime.

Enhanced Retrofit: The enhanced retrofitinvolves re-engineering the chiller to becompatible with the properties of the newenvironmentally friendly refrigerant. Re-engineering includes minimizing loss ofcooling capacity and maximizing chillerefficiency. The redesigned componentsconsist of but are not limited to gaskets,O-rings, resized compressor impeller, andrevised refrigerant expansion orificesystem.

EPA: Environmental Protection Agency

EPAMLR: EPA maximum leak rate. Themaximum percentage of the total charge amachine can lose based on a 12-month


period without exceeding EPA leakagelimitations. Exceeding this rate does notconstitute a violation unless the leak is notrepaired, or a plan to replace the equip-ment has not been established within 30days.

ESCO: Energy Conservation ServiceCompany

ESF: Equipment Survey Form

ETL: Engineering Technical Letter

FAR: Federal Acquisition Regulation

FEMP: Federal Energy ManagementProgram

FLA: full-load amps

Handbook: the Refrigerant ManagementHandbook

HCFC: hydrochlorofluorocarbon

HD: high density

HFC: hydrofluorocarbon

High-Pressure Appliance: Uses refriger-ant with a boiling point between -500 C(-58° F) and 10° C (50° F) at atmosphericpressure.

Household Refrigeration: Refrigeratorsand freezers intended primarily for house-hold use. This equipment may be used out-side the home.

HQ AFCESA/EN: Systems EngineeringDirectorate, Headquarters, Air Force CivilEngineer Support Agency

HQ USAF/CEVV: Prevention Division,Directorate of Environmental Quality,Headquarters U.S. Air Force

HVAC: heating, ventilating, and airconditioning

HW: hot water

Industrial Process Refrigeration: Com-plex customized appliances used in thechemical, pharmaceutical, petrochemical,and manufacturing industries. The sector isalso defined to include industrial icemachines and ice rinks.

IPLV: integrated part-load value. Asingle kW/ton value that describes part-load efficiency of a chiller at 25, 50, 75,and 100 percent full load conditions basedon a “typical” number of operational hoursat each. It is based on 7° C (44° F) chilledwater and 29° C (85° F) condenser watertemperatures. It is defined in ARI Standard550-92 by the equation IPLV = 0.05(100% kW/ton) + 0.3 (75% kW/ton) +0.4 (50 % kW/Ton) + 0.25 (25% kW/ton),

IR: infrared-based

IR-PAS: infrared-photoacoustic-based

kW: kilowatt

kWh: kilowatt-hour

LCC: life-cycle cost. The total cost asso-ciated with the purchase, installation,operating, and maintenance of a system orequipment over its expected life.

LCCID: Life-Cycle Cost in Design

Load Diversity: To allow a lesser maxi-mum load on the central plant than thesum of the loads for separate systems.

Low-Loss Fitting: Any device intended toestablish a connection between hoses, airconditioning and refrigeration equipment,or recovery or recycling equipment thatwill close automatically or must be manu-ally closed before disconnecting, therebyminimizing the release of refrigerant to theatmosphere

R-3


Low-Pressure Appliance: Appliances thatuse a refrigerant with a boiling point above10° C (50° F) at atmospheric pressure.

Major Maintenance, Service, orRepair: Maintenance, service, or repairthat involves removal of the compressor,evaporator, or auxiliary heat exchangercoil.

MAJCOM: Major command

MBtu: 1,000 Btu/hr

MFH: military family housing

MILCON: Military Construction

MOA: Memorandum of Agreement

MRR: marginal refrigerant reserve. Thesum of the appropriate EPAMLRs (15% or35%) for each machine plus the CRR foreach refrigerant.

MSDS: material safety data sheets

MVAC: motor vehicle air conditioning

NEMA: National Electric ManufacturersAssociation

NEPA: National Environmental PolicyAct

NIOSH: National Institute for Occupa-tional Safety & Health

NIST: National Institute of StandardsTechnology

ODC: ozone-depleting compounds

ODP: ozone-depletion potential

and

OEM: original equipment manufacturer

Off-peak: Time period of the day whenenergy costs are reduced by a utility due tobelow-normal demand.

On-peak: Time period of the day whenenergy costs are raised by a utility due toabove-normal demand.

O&M: operations and management oroperations and maintenance

O&S: operations and services

Opening an Appliance: Any service,maintenance, or repair on an appliance thatcould be reasonably expected to releaserefrigerant to the atmosphere, unless therefrigerant was previously recovered fromthe appliance.

OPR: offices of primary responsibility

OSD: Office of the Secretary of Defense

OSHA: Occupational Safety and HealthAdministration

Partition: Any wall, ceiling, or floorassembly which is not exposed to outsideambient conditions.

POC: point of contact

PPBS: planning, programming, and bud-geting system

PPM: parts per million

PPP: Pollution Prevention Program

PRO-ACT: PRO-ACT stands for proac-tive and is an information clearinghouselocated at Brooks APB, Headquarters AirForce Center for Environmental Excel-lence, HQ AFCEE, commercial phonenumber (800) 233-4356 and DSN240-4214.

Primary Chilled Water Pump: Pumpwhich distributes chilled water between thechiller plant and the secondary chilledwater pumps serving the load.

R-4


PRV: pressure relief valve

PSIG: pounds per square inch gage

Push/Pull Method of Recovery: Thepush/pull refrigerant recovery method isdefined as the process of transferringliquid refrigerant from a refrigerationsystem to a receiving vessel by loweringthe pressure in the vessel and raising thepressure in the system, and by connectinga separate line between the system liquidport and the receiving vessel.

PVC: polyvinylchloride

RDT&E: Research, development, testingand evaluation

RCRA: Resource Conservation andRecovery Act

Reclaim: Reprocessing of refrigerant tonew product specifications. The purity ofthe final product must be chemically veri-fied to meet ARI 700 standards.

Recover: Removal of refrigerant from asystem. Testing the condition of the re-frigerant is not necessary.

Recycle: To clean refrigerant for re-usewithout chemical purity verification.

Retirement: The ability to recover refrig-erant from a machine by means of retrofitor replacement.

Retrofit: The conversion of equipmentcontaining a CFC refrigerant to use a moreenvironmentally friendly refrigerant.

RM: refrigerant manager, An individualselected to manage the BRMP and beresponsible for the RMP development.

RMP: Refrigerant Management Plan: aschedule with the associated costs required

to eliminate CFC refrigerants in AC/Requipment at an AFB. The ideal Scheduleallows existing equipment to operate untilthe end of its economic life while main-taining sufficient refrigerant reserves.Reserves are maintained through inter-baserefrigerant transfers, purchase waivers,and recovery of equipment refrigerantcharges upon retirement.

SC: shading coefficient

SCBA: self-contained breathing apparatus

Schedule: Equipment Retirement Sched-ule. A pre-determined plan developed toestablish the specific dates and order whichAC/R equipment retirements should beconducted to maintain sufficient refrigerantinventories and maintain annual fundingrequirements as level as possible.

SCL: shading cooling load

Secondary Chilled Water Pump: Pumpwhich serves the end users. Pump is sizedto overcome only the piping losses in thesecondary piping loop and in the endusers.

Self-Contained Recovery Equip-ment: Self-contained recovery equipmentthat has its own means to draw refrigerantout of an appliance.

SIOH: supervision, inspection, and over-head

SIR: savings-to-investment ratio

Small Appliance: Air conditioner, refrig-eration equipment, or freezers which arefully manufactured, charged, and hermeti-cally sealed in a factory with a charge offive pounds or less.

SPB: simple payback

R-5


Standard Contaminated RefrigerantSample: A mixture of new and/orreclaimed refrigerant and specifiedquantities of identified contaminants whichare representative of field obtained, usedrefrigerant samples and which constitutethe mixture to be processed by theequipment under testing.

System-Dependent RecoveryEquipment: System-dependent recoveryequipment relies on the compressor of theappliance or the pressure of the refrigerantin the appliance to extract the refrigerantfrom the appliance.

TAN: total acid number

TDS: technical data (TechData) sheet

Technician: Any person who performsmaintenance, service, or repair to airconditioning or refrigeration equipmentthat could reasonably be expected torelease CFCs or HCFCs to theatmosphere.

TESS: thermal energy storage system

TIC: total installed charge

TLV: threshold limit value

Ton of Refrigeration: 12,000 Btu/hr ofcooling capacity

Ton-Hour: the amount of cooling (intons) provided in a given amount of time(in hours).

UL: Underwriters’ Laboratory

UN: United Nations

UNEP: United Nations EnvironmentProgramme

VAV: variable air volume

Very High-Pressure Equipment: Airconditioning and refrigeration equipmentwhich contains refrigerant with a boilingpoint below -50° C (-580 F) at atmospher-ic pressure.

WIMS: Work Information ManagementSystem

WIMS-ES PP: Work Information Man-agement System—Environmental SystemPollution Prevention

R.2 Bibliography

101-239, 103 stat. 2106, December 19,1989. (Omnibus Budget ReconciliationAct of 1989).

29 C.F.R. 1910.120 (1989). (OSHA1910.12).

40 C.F.R. Part 82 (1993).

American National Standards Institute.American National Standards Practicesfor Respiratory Protection Z88.2-1980.New York, NY: ANSI, 1980. (ANSIZ88.2-1980).

American National Standards Institute.Hazardous Industrial Chemicals -Precautionary Labeling Z129. 1-1988.New York, NY: ANSI, 1988. (ANSIZ129.1-1988).

American Refrigerant Institute. RefrigerantRecovery/Recycling Equipment. ARI740-93. Arlington, VA: ARI, 1993.(ARI 740-93).

American Refrigerant Institute. Specifica-tions for Fluorocarbon Refrigerants.ANSI/ARI 700-88. Arlington, VA:ANSI, 1988. (ARI 700-88).

R-6


American Society of Heating, Refrigerat-ing and Air Conditioning Engineers,Inc. ASHRAE Standard Number Desig-nation and Safety Classification ofRefrigerants. ANSI/ASHRAE 34-1992.Atlanta, GA: ASHRAE, 1992.(ASHRAE 34-1992).

American Society of Heating, Refriger-ating and Air Conditioning Engineers,Inc. ASHRAE Standard: An AmericanNational Standard Safety Code forMechanical Refrigeration.ANSI/ASHRAE 15-1994. Atlanta, GA:ASHRAE, 1994. (ASHRAE 15-1994).

American Society of Heating, Refrigerat-ing and Air Conditioning Engineers,Inc. 1993 ASHRAE HandbookFundamentals. ASHRAE -1993.Atlanta, GA: ASHRAE, 1993.(ASHRAE Handbook - 1993).

Clean Air Act Amendments. Public Law101-59, 15 November 1990. (CleanAir Act Amendments or CAAA).

Compressed Gas Association. PamphletC7-92 Guide to the Preparation ofPrecautional Labeling and Marking ofCompressed Gas Containers.Arlington, VA: Compressed GasAssociation, 1992. (Compressed GasAssociation C7-92).

National Institute of Standards and Tech-nology. Energy Prices and DiscountFactors for Life Cycle Cost Analysis.NISTR 85-3272-7. Rockville, MD:NISTR, 1993. (NISTR 3272-7).

U.S. Air Force. Air Force Civil Engin-eer Support Agent y. EngineeringTechnical Letter (ETL) 91-7, Chloro-

fluorocarbon (CFC) Limitation inHeating, Ventilating, and AirConditioning (HVAC) Systems. 21August 1993. (ETL 91 -7).

U.S. Air Force. Secretary and Chief ofStaff of the Air Force. ActionMemorandum: Air Force Ban onPurchase of Ozone DepletingChemicals (ODC’S). 7 January 1993.(Action Memorandum -7 January1993).

R.3 Additional BibliographicReferences

Additional bibliographic references areprovided as suggested sources where morein-depth information can be found. Thesesources are listed by the appendix theysupport.

R.3.1 Appendix A

U.S. Air Force. Air Force CivilEngineering Support AgencyHeadquarters, K. Q. Hart. Rules andRegulations. U.S. Air ForceRefrigerant Management Program.

U.S. Air Force. Engineering SupportLetter (ETL) 88-8, Chlorofluorocarbon(CFC) Limitation in Heating,Ventilating, and Air Conditioning(HVAC) Systems. October 4, 1988.

R-7


R.3.2 Appendix B

Electrical Power Institute. CFR Update,#SU-102097. March 5, 1993.

The Trane Company. ApplicationsEngineering Manual, “RefrigerationSystem Equipment Room Design. ”AM-3. La Crosse, WI: The TraneCompany, August 1992.

R.3.3 Appendix C

E.I. Du Pont de Nemours. SUVA HPRequirements, Properties, Uses, Stor-age, and Handling. Booklet No. P-HP.Wilmington, DE: Du Pont, 1993.

Nott, Joe; Shaw, Dick; Tomczyk, John;Wagner, Larry. Refrigerant Transitionand Recovery Booklet, 3rd rev. LaCrosse, WI: The Trane Company,July 1993.

R.3.4 Appendix D

Althouse, Andrew D., Turnquist, Carl H.,Modern Refrigeration and Air Condi-tioning.

E.I. Du Pont de Nemours. Leak Detectionfor Alternative Refrigerants.#ARTD-27. Wilmington, DE: DuPont, 1992.

The Trane Company. ApplicationsEngineering Manual, “RefrigerationSystem Equipment Room Design. ”REF-AM-3. La Crosse, WI: The TraneCompany, August 1992.

The Trane Company. Approaching theSystem, Technical Training StudentHandbooks. La Crosse, WI: The TraneCompany.

The Trane Company. Bracciano, AlfredF., Reducing Refrigerant Emissions,Technical Training Student Handbook.La Crosse, WI: The Trane Company,1988.

R.3.5 Appendix E

American Refrigeration Institute.Refrigerant Recovery/RecyclingEquipment. ARI 740-93. Arlington,VA: ARI, 1993.

The Trane Company. Technical Booklet -Low Pressure Recovery Techniques.ST-MNL-LP2. La Crosse, WI: TheTrane Company, May 1993.

U.S. Air Force. Engineering SupportLetter (ETL) 88-8. Chlorofluorocarbon(CFC) Limitation in Heating,Ventilating, and Air Conditioning.October 4, 1988.

R.3.6 Appendix F

E.I. Du Pont de Nemours. Leak Detectionfor Alternative Refrigerants. #ARTD-27. Wilmington, DE: Du Pont, 1992.

The Trane Company. The Technician asan Advisorj Technical Training StudentHandbook. La Crosse, WI: The TraneCompany, 1993.

U.S. Air Force. Air Force CivilEngineering Support Group. K. QuinnHart. U.S. Air Force RefrigerantManagement Software Program.

R.3.7 Appendix G

U.S. Air Force. Air Force CivilEngineering Support Group. K. QuinnHart. U.S. Air Force RefrigerantManagement Software Program.

R-8

Appendix R – Glossary of Terms, Definitions, and Bibliography

R.3.8 Appendix J

The Trane Company. Refrigeration SystemEquipment Room DesignApplications Engineering Manual. LaCrosse, WI: The Trane Company.

R.3.9 Appendix M

American Refrigeration Institute. Standurdfor Centrifugal or Rotary Water-Chilling Packages. ARI 550-90.Arlington, VA: ARI, 1990.

R.3.10 Appendix N

American Refrigeration Institute. Standardfor Centrifugal or Rotary Water-Chilling Packages. ARI 550-90.Arlington, VA: ARI, 1990.

R.3.11 Appendix O

American Refrigeration Institute. Standardfor Centrifugal or Rotary Water-Chilling Packages. ARI 550-90.Arlington, VA: ARI, 1990.

Bell & Gossett Fluid Technology Corp.Primary/Secondary Pumping Applica-tion Manual. No. TEH-775. MortonGrove, IL: Bell & Gossett.

U.S. Air Force. Engineering WeatherData. Air Force Manual. AFM88-29.

R.3.12 Appendix Q

U.S. Air Force. Engineering WeatherData. Air Force Manual. AFM88-29,

R-9 (R-10 Blank)
