DOCUMENT RESUME - ERIC · creating glare and noise levels do not interfere with activities. Sanitation, drinking water, fire protection, and other factors affecting health and safety

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Agle, Elizabeth; Galbraith, SusanBuilding Air Quality: A Guide for Building Owners andFacility Managers.Environmental Protection Agency, Washington, DC. Indoor AirDiv.; National Inst. for Occupational Safety and Health(DHHS/PHS), Cincinnati, OH.DHHS-NIOSH-91-114; EPA-400-T-91-033ISBN-0-16-035919-81991-12-00234p.; For a related "Action Plan", see EF 005 117.Superintendent of Documents, U.S. Government PrintingOffice, Mail Stop: SSOP, Washington, DC 20402-9328.Guides Non-Classroom (055)MF01/PC10 Plus Postage.*Air Pollution; *Building Operation; Data Collection;Documentation; Facility Guidelines; *Facility Improvement;Organizational Communication; Planning; Problem Solving;*Quality Control*Indoor Air Quality

The past two decades have witnessed increased concerns overthe health and comfort of indoor air quality (IAQ), but little indoorair-related information has been targeted at building owners and facilitymanagers of public and commercial buildings. This manual, specificallycreated for such a population, provides guidance on preventing, identifying,and correcting IAQ problems. The manual is divided into three topic areas.The first provides introductory material that explores the factors affectingIAQ and the organizational communication required for identifying potentialIAQ problems. The second area advises building owners and facility managerswho currently do not have an air-quality problem on how to prevent IAQproblems from arising. The development of an IAQ profile and the managementof buildings for good IAQ are discussed. The third area provides guidance forresolving current air quality problems, such as diagnosing and mitigating IAQproblems and guidance on hiring IAQ professional assistance. Two sectionscontaing 7 appendixes and 15 forms (checklists, profiles, worksheets, etc.)comprise half of the document. Fix appendixes discuss: (1) common IAQmeasurements; (2) HVAC systems and indoor air quality; (3) moisture, mold andmildew; (4) asbestos; and (5) radon. The other two appendixes are: (1) a

glossary and list of acronyms; and (2) a list of resources. (GR)

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Buil in ir ualiA Guide for Building Ownersand Facility Managers

EPA1\111131111114

U.S. DEPARTMENT OF EDUCATIONOffice of Educational Research end Improvement

EDUCATIONAL RESOURCES INFORMATIONCENTER (ERIC)

This document has been reproduced asreceived from the person or organizationoriginating it.

O Minor changes have been made toimprove reproduction quality.

Points of view or opinions stated in thisdocument do not necessarily representofficial OERI position or policy

BEST COPYAVAILABLE

December 1991

Building Air QualityA Guide for Building Owners and Facility Managers

&EPAU.S. Environmental Protection Agency

Office of Air and Radiation

Office of Atmospheric and Indoor Air Programs

Indoor Air Division

U.S. Department of Health and Human Services

Public Health Service

Centers for Disease Control

National Institute for Occupational Safety and Health

CDCCENTERS FOR =EASE CONTROL

NIC151-1

For sale by the U.S. Government Printing OfficeSuperintendent of Documents. Mail Stop: SSOP. Washington, DC 20402-9328

ISBN 0-16-035919-8

3 Printed on Recycled Paper

DISCLAIMERThis document has beenreviewed in accordancewith policies at the U.S.Environmental ProtectionAgency and the NationalInstitute for OccupationalSafety and Health. Infor-mation provided is basedupon current scientific andtechnical understandingof the issues presented.Following the advice givenwill not necessarily providecomplete protection in allsituations or against allhealth hazards that may becaused by indoor air poll-ution. Mention of any tradenames or commercial prod-ucts does not constituteendorsement or recommen-dation for use.

4

Contents

Foreword vii

Note to Building Owners and Facility Managers ix

Acknowledgements xiii

TAB I: BASICS

Section 1: About This Document 1

Section 2: Factors Affecting Indoor Air Quality 5

Sources of Indoor Air Contaminants 5

HVAC System Design and Operation 6

Pollutant Pathways and Driving Forces 9

Building Occupants 10

Section 3: Effective Communication 13

Communicating to Prevent IAQ Problems 13

Communicating to Resolve IAQ Problems 15

TAB II: PREVENTING IAQ PROBLEMS

Section 4: Developing an IAQ Profile 19

Skills Required to Create an IAQ Profile 20

Steps in an IAQ Profile 21

Section 5: Managing Buildings for Good IAQ 31

Developing an IAQ Management Plan 31

TAB III: RESOLVING IAQ PROBLEMS

Section 6: Diagnosing IAQ Problems 45

Overview: Conducting an IAQ Investigation 46

Initial Walkthrough 47

Collecting Additional Information 49

Collecting Information about Occupant Complaints 50

Using the Occupant Data 53

Collecting Information about the HVAC System 57

Using the HVAC System Data 62

Collecting Information about Pollutant Pathways and Driving Forces 68

Using Pollutant Pathway Data 70

Collecting Information on Pollutant Sources 72

Using Pollutant Source Data 74

Contents iii5

Sampling Air for Contaminants and Indicators 74Complaints Due to Conditions Other Than Poor Air Quality 77Forming and Testing Hypotheses 78

Section 7: Mitigating IAQ Problems 81Background: Controlling Indoor Air Problems 81Sample Problems and Solutions 86Judging Proposed Mitigation Designs and Their Success 102

Section 8: Hiring Professional Assistance to Solve an IAQ Problem 105Make Sure That Their Approach Fits Your Needs 105Selection.' Criteria 106

TAB IV: APPENDICES

Appendix A: Common IAQ Measurements - A General Guide 109Overview of Sampling Devices 109Simple Ventilation/Comfort Indications 110Air Contaminant Concentrations 115

Appendix B: HVAC Systems and Indoor Air Quality. 121Background 121Types of HVAC Systems 122Basic Components of an HVAC System 123ASHRAE Standards and Guidelines 137

Appendix C: Moisture, Mold and Mildew 141Background on Relative Humidity, Vapor Pressure, and Condensation 141

Taking Steps to Reduce Moisture 143

Identifying and Correcting Common Problems From Mold and Mildew 145

Appendix D: Asbestos 147EPA and NIOSH Positions on Asbestos 148Programs for Managing Asbestos In-Place 149Where to Go for Additional Information 150

Appendix E: Radon 151Building Measurement, Diagnosis and Remediation 151

Where To Go for Additional Information 152

Appendix F: Glossary and Acronyms 153

Appendix G: Resources 157Federal Agencies with Major IAQ Responsibilities 157Other Federal Agencies with Indoor Air Responsibilities 160State and Local Agencies 160Private Sector Contacts 161Publications 164Training 167

iv Contents

TAB V: INDOOR AIR QUALITY FORMSIAQ Management Checklist 171

Pollutant Pathway Record For IAQ Profiles 175

Zone/Room Record 177

Ventilation Worksheet 179

Indoor Air Quality Complaint Form 181

Incident Log 183

Occupant Interview 185

Occupant Diary 187

Log of Activities and System Operation 189

HVAC ChecklistShort Form 191

HVAC ChecklistLong Form 195

Pollutant Pathway Form For Investigations 211

Pollutant and Source Inventory 213

Chemical Inventory 221

Hypothesis Form 223

This document is in the public domain. It may be reproduced in whole or in part by an individual or organization without permission. If it

is reproduced, however, EPA and NIOSH would appreciate knowinghow it is used. Write the Indoor Air Division (ANR-445W), Office

of Air and Radiation, U.S. Environmental Protection Agency, Washington, DC 20460.

Contents v 7

Foreword

In the past two decades, the number ofpeople requesting information and assis-tance on health and comfort concernsrelated to indoor air quality from the U.S.Environmental Protection Agency (EPA)and the National Institute for OccupationalSafety and Health (NIOSH) has risensteadily. Although many studies on indoorair quality have been reported in technicalpublications and proceedings during theseyears, little indoor air-related informationhas been targeted at owners and facilitymanagers of public and commercialbuildings who are the people in the bestposition to prevent and resolve indoor air

problems.In recognition of the need for practical

indoor air quality advice for buildingowners and facility managers, EPA andNIOSH decided to work jointly to producewritten guidance on preventing, identify-ing, and correcting indoor air qualityproblems. The distinct perspectives of thetwo agencies are reflected in this docu-ment.

Since 1971, NIOSH has conductedmore than 600 indoor air quality investiga-tions in office (non-industrial, non-residential) buildings under the HealthHazard Evaluation Program. Over time,NIOSH has developed a "solution-

oriented" approach to these investigations.This document draws extensively on theexperience of NIOSH in investigating andcorrecting indoor air quality problems inthese types of buildings.

In 1986, Congress mandated that EPAconduct research and develop informationon indoor air quality. To carry out itsinformation dissemination responsibilities,EPA's Indoor Air Division has produced anumber of publications which have beendistributed to a wide range of audiencesand will launch an indoor air qualityinformation clearinghouse in 1992. Inaddition, the Indoor Air Division isdeveloping several guidance documents onbuilding design and management practices.This publication is part of that effort.

The guidance presented here is basedon what is known and generally acceptedat this time in the relevant fields ofbuilding science and indoor air quality.EPA and NIOSH anticipate that thisdocument may later be revised to includemore detailed guidance as researchcontinues and our knowledge grows. Inthe meantime, building owners and facilitymanagers can use the resources listed inAppendix G to supplement and update theinformation presented here.

Foreword vii

Note to Building Owners andFacility Managers

From marketing and negotiating leasesand maintenance contracts to planning forfuture expansion, operating a commercialor public building is a complex processthat leaves you little time for unnecessaryactivities. Working with your facility staff,you make an effort to provide a pleasantsetting and are accustomed to dealingwith occupant complaints about roomtemperature, noise, plumbing systemproblems, and other elements of thebuilding environment.

A healthy indoor environment is one inwhich the surroundings contribute toproductivity, comfort, and a sense of healthand well being. The indoor air is free fromsignificant levels of odors, dust and con-taminants and circulates to preventstuffiness without creating drafts. Tem-perature and humidity are appropriate tothe season and to the clothing and activityof the building occupants. There is enoughlight to illuminate work surfaces withoutcreating glare and noise levels do notinterfere with activities. Sanitation,drinking water, fire protection, and otherfactors affecting health and safety are well-planned and properly managed.

Good air quality is an importantcomponent of a healthy indoor environ-ment. For the purposes of this document,the definition of good indoor air qualityincludes:

introduction and distribution of adequateventilation aircontrol of airborne contaminantsmaintenance of acceptable temperatureand relative humidity

A practical guide to indoor air quality(IAQ) cannot overlook temperature andhumidity, because thermal comfort

concerns underlie many complaints about"poor air quality." Furthermore, tempera-ture and humidity are among the manyfactors that affect indoor contaminantlevels.

It is important to remember that whileoccupant complaints may be related totime at work, they may not necessarily bedue to the quality of the air. Other factorssuch as noise, lighting, ergonomic stressors(work station and task design), and job-related psychosocial stressors canindividually and in combinationcontribute to the complaints. Theseproblems are briefly addressed in thisdocument.

Good indoor air quality enhancesoccupant health, comfort, and workplaceproductivity. Rental properties can gain amarketing advantage if they are known tooffer a healthy and pleasant indoor envi-ronment. Failure to respond promptly andeffectively to IAQ problems can haveconsequences such as:

increasing health problems such ascough, eye irritation, headache, andallergic reactions, and, in some rarecases, resulting in life-threateningconditions (e.g., Legionnaire's disease,carbon monoxide poisoning)reducing productivity due to discomfort

or increased absenteeismaccelerating deterioration of furnishingsand equipmentstraining relations between landlords andtenants, employers and employeescreating negative publicity that could putrental properties at a competitivedisadvantageopening potential liability problems(Note: Insurance policies tend to excludepollution-related claims)

Note to Buildig Owners and Facility Managers ix

Provision of good air quality requiresconscientious effort by both building staffand occupants. The commitment toaddress IAQ problems starts with thebuilding owner or facility manager, theperson who has an overview of theorganization, sets policy, and assigns staffresponsibilities. You have the authority tosee that an IAQ policy is articulated andcarried out, the ability to identify staff withskills that enable them to react promptlyand effectively to complaints, and theincentive to initiate a program that willprevent indoor air problems in the future.As you decide how best to respond to thechallenge of preventing and resolvingindoor air quality problems in yourbuilding, it will be helpful to keep in mindthe following thoughts:

It is important to establish a processthat encourages an active exchange ofinformation.

Without an open communications policy,an atmosphere of distrust may be createdthat complicates your efforts to diagnoseand correct problems.

Facility staff are in a position to noticemalfunctioning equipment or accidentalevents that could produce indoor airquality problems.

They can play a critical role in identifyingproblem situations and averting IAQcrises. On the other hand, if staff are notaware of IAQ issues, their activities canalso create indoor air quality problems.

Facility staff are often instructed to keepenergy costs to a minimum.

Changes in building operation intended tosave energy have sometimes contributed toIAQ problems (for example, by reducingthe flow of outdoor ventilation air withouttaking action to maintain the quality of therecirculated air). The correction of IAQ

1 0

problems has sometimes led to reducedenergy use due to the efficiency associatedwith a cleaner and better controlledheating, ventilation, and air conditioning(HVAC) system. The energy needed tocondition and distribute ventilation air isonly a small part of total building energyconsumption and is far overshadowed byother operating costs (such as personnel).Attempting to limit operating costs byreducing ventilation can be a falseeconomy, if it leads to problems such asincreased occupant complaints, reducedproductivity, and absenteeism.

Every complaint merits a response.

Many indoor air quality problems are notdifficult to correct and can be solved within-house expertise. However, gatheringrelevant information about the problemand identifying appropriate correctiveactions are likely to require a coordinatedeffort by people with a variety of skills.

An indoor air quality problem maybe the direct or indirect result ofanapparently minor modification.

Actions such as the placement of interiorroom dividers, the introduction of newoffice equipment, and personal activitiessuch as cooking can have an impact onindoor air quality. Communicationbetween building management andbuilding occupants regarding their respec-tive responsibilities is a critical element inthe management of indoor air quality.

Indoor air quality in a large building isthe product of multiple influences, andattempts to bring problems under controldo not always produce the expected result.

Some indoor air quality problems arecomplex and may require the assistance ofoutside professionals. When contractingfor services, you need to be an informedclient to avoid unnecessary costs anddelays in solving the problem.

x Note to Building Owners and Facility Managers

If there is reason to believe that an IAQproblem may have serious health implica-tions, appropriate experts such as occupa-tional physicians, industrial hygienists,and mechanical engineers should becalled in as soon as possible.

In-house investigations by non-profession-als are not recommended in such cases(e.g., if individuals are being hospitalizedbecause of exposure inside the building).

Public and commercial buildings canpresent a wide range of IAQ problems.

The variety of unique features in theirdesign and usage (e.g., apartment build-ings, hospitals, schools, shopping malls)make a wide range of IAQ problems pos-sible. In apartment buildings, for example,each residential unit can produce cookingodors and the operation of kitchen exhaustfans is generally outside the control ofbuilding management. The basic informa-

tion and problem-solving processes in thisguide can be applied, with necessary adap-tations, to a wide range of building types.

This document was written to be a use-ful resource for you and your staff in pre-venting and resolving occupants' com-plaints that may be related in some way tothe quality of the indoor air. It providesbackground information followed by"how-to" guidance for you and your in-house staff. The practical problem-solvingtechniques it describes have been appliedsuccessfully by NIOSH and other investi-gators. If complaints are not resolved aftercareful application of this guidance, out-side help will probably be needed. Infor-mation on possible sources of outside helpis included. As you read this document, orturn it over to your staff to implement,EPA and NIOSH urge you to maintain apersonal involvement in this issue.

1 1

Note to Building Owners and Facility Managers xi

SELECTED INDOORAIR QUALITYPROBLEMS

This box is provided to help building owners and facility managers getacquainted with examples of IAQ problem indicators and associatedresponses. Some IAQ problem situations require immediate action.Other problems are less urgent, but all merit a response.

Problems Requiring There have been complaints of head-Immediate Action aches, nausea, and combustion odors.

Carbon monoxide poisoning is apossibility. Investigate sources ofcombustion gases right away.

One or more occupants of your buildinghave been diagnosed as havingLegionnaire's disease.

This is a potentially life-threateningillness. Request Health Departmentassistance in determining whetheryour building may be the source ofthe infection.

Staff report that water from a roof leakhas flooded a portion of the carpeting.

If damp carpeting cannot be lifted andthoroughly dried within a short time,it might need to be discarded. Propercleaning and disinfection proceduresmust be used to prevent the growthof mold and mildew that could causeserious indoor air quality problems.

Problems ThatRequire AResponse, ButAre NotEmergencies

Inspection of the humidification systemreveals an accumulation of slime andmold. There have been no healthcomplaints suggesting lAO problems.

Inadequately maintained humidifierscan promote the growth of biologicalcontaminants. Clean equipmentthoroughly, and consider modifyingmaintenance practices.

A group of occupants has discoveredthat they share common symptoms ofheadaches, eye irritation, and respira-tory complaints and decided that theirproblems are due to conditions in thebuilding.

The symptoms described suggest anIAQ problem that is not life-threaten-ing, but it would be wise to respondpromptly.

Immediately after delivery of newfurnishings (furniture or carpeting),occupants complain of odors anddiscomfort.

Volatile compounds emitted by thenew furnishings could be causing thecomplaints.

Local news articles suggest that somebuildings in the area have high indoorradon levels.

The only way to determine the indoorradon concentration in a givenstructure is to test in appropriatelocations.

You wonder whether some old pipeinsulation contains asbestos.

12

Asbestos can be positively identifiedonly by laboratory analysis.

xii Note to Building Owners and Facility Managers

Acknowledgements

he development of this document,Building Air Quality: A Guide forBuilding Owners and Facility Managers,has been a joint undertaking of theIndoor Air Division in the Office ofAtmospheric and Indoor Air Programs of

the United States EnvironmentalProtection Agency and the NationalInstitute for Occupational Safety andHealth. The document was preparedunder the direction of Robert Axelrad,Director, EPA Indoor Air Division andPhilip J. Bierbaum, Director, NIOSHDivision of Physical Sciences andEngineering.

EPA and NIOSH appreciate the timethat many organizations and individualstook to share ideas, discuss their ownpractical experiences, and review manydrafts of this document. Many of theideas raised by these reviewers havebeen incorporated into this document.

Two people had primary responsibilityfor developing the content and format ofthe document. Elizabeth Agle, the EPAproject manager, developed the structureof the document, assembled the teams ofcontributors and reviewers, and provideddirection and untiring support as the pro-ject came to fruition. Susan Galbraith,Cogito Technical Services, served as theprincipal writer. She brought to the taskboth considerable writing skills and abasic understanding of how buildingsoperate that proved invaluable through-out the process of conceptualizing andcreating this document.

EPA and NIOSH gratefully acknowl-edge the important contributions of TerryBrennan, Camroden Associates; EdLight, Pathway Diagnostics; and WilliamA. Turner, The H. L. Turner Group, who

served as the team of core technicaladvisors for this document. These indi-viduals contributed a substantial amount ofwritten material and thoughtful commentson the many drafts and, most importantly,their considerable practical experience inidentifying and resolving indoor air qualityproblems. Joseph Lstiburek, BuildingScience Corporation, contributed much ofthe material on the problem of moisture.EPA and NIOSH particularly wish to thankthe staff of The Charles E. Smith Compa-nies who reviewed numerous drafts of thedocument and made invaluable commentsfrom a building management perspective.

The photographs were donated by: TerryBrennan, Camroden Associates; MichaelCrandall, NIOSH; Ed Light, PathwayDiagnostics; Joseph Lstiburek, BuildingScience Corporation; Phil Morey, ClaytonEnvironmental Services; Tedd Nathanson,Public Works Canada; Robert Olcerst,Brujos Scientific Inc.; Stan Salisbury,NIOSH; William A. Turner, The H. L.Turner Group; and Kenneth Wallingford,NIOSH. Additional slides came from theNIOSH Health Hazard Evaluation Programand from the Occupational Safety andHealth Administration.

A large number of people within bothEPA and NIOSH commented on the draftsof the document. EPA and NIOSHrecognize the following staff for theirparticular contributions: John Girman,Elissa Feldman, Pauline Johnston, SuePerlin, David Mudarri, Jack Primack, BobThompson, Kevin Teichman, CharlesTruchillo, and Jim Wilson, EPA; andMichael Crandall, Jerome Flesch, RichardGorman, Joseph Hurrell, Pantelis Rentosand Mitchell Singal, NIOSH.

Acknowledgements xiii13

The draft document was widely circu-lated for review outside these agencies.EPA and NIOSH thank the followingindividuals who reviewed all or part of thedocument and submitted comments:

Allen C. AbendMaryland Department of EducationCharles A. AchillesInstitute of Real Estate ManagementHenry A. AndersonWisconsin Department of Health andSocial ServicesDavid W. BeargLife Energy AssociatesW. David BevirtSheet Metal and Air ConditioningContractors AssociationBarbara BillauerInternational Council of Shopping CentersBob BockholtNational Apartment AssociationH. E. BurroughsH. E. Burroughs & Associates, Inc.Harriet BurgeUniversity of Michigan Medical CenterPaul A. CammerBusiness Council on Indoor AirJames L. CogginsEnergy Applications, Inc.Geraldine V. CoxChemical Manufacturers AssociationEaron S. DavisEnvironmental Health ConsultantJohn E. Di Fazio, Jr.Chemical Specialties ManufacturersAssociationJames C. DinegarBuilding Owners and ManagersAssociation InternationalStephen D. Dries lerNational Association of RealtorsSandra EberleU.S. Consumer Product SafetyCommissionPaul C. FiducciaInternational Council of Shopping CentersRichard B. GammageOak Ridge National LaboratoryMatthew GillenOccupational Health Foundation

1 4xiv Acknowledgements

William H. GroahHardwood Plywood ManufacturersAssociationShirley J. HansenHansen AssociatesSteven B. HaywardIndoor Air Quality Program, CaliforniaDepartment of Health ServicesJohn HenshawAmerican Industrial Hygiene AssociationBion HowardAlliance to Save EnergyW. T. IrwinCertainTeed CorporationPaul JacobetzBriiel & Kjaer Instruments, Inc.

William D. KelleyAmerican Conference of GovernmentalIndustrial Hygienists, Inc.Jay KiriharaThe Trane Company

Daniel A. La HartMaryland Department of the EnvironmentMary LamielleNational Center for EnvironmentalHealth Strategies

Ellen LarsonAir Conditioning Contractors of AmericaDavid LeeAssociation of Local Air PollutionControl OfficialsEugene L. LehrU.S. Department of TransportationHal LevinIndoor Air Bulletin

William H. McCredieNational Particleboard AssociationJean F. MatesonMateson Environmental Management, Inc.Keith MestxichFood and Allied Service TradesEugene M. MoreauIndoor Air Program,Maine Department of Human ServicesNiren L. NagdaGEOMET Technologies, Inc.Fred NelsonNational Foundation for theChemically Hypersensitive

Laura OatmanIndoor Air Quality Program,Minnesota Department of Health

Andrew PersilyNational Institute for Standards andTechnologyGeorge R. PhelpsThermal Insulation ManufacturersAssociation, Inc.William A. PugsleyLincoln-Lancaster County HealthDepartment (Nebraska)

G.S. RajhansOntario Ministry of Labour

Susan RoseU.S. Department of Energy

Steven A. ScalaU.S. Public Health Service

James SharpeThe Charles E. Smith Companies

Richard J. Shaughnessy,.IIIIndoor Air Program, University of Tulsa

Thomas J. ShepichOccupational Safety and HealthAdministrationHenry J. SingerGeneral Services AdministrationPhilip A. SquairAir-Conditioning and RefrigerationInstituteJohn H. StrattonSheet Metal and Air ConditioningContractors AssociationKenneth M. SufkaAssociated Air Balance Council

John M. TalbottU.S. Department of Energy

Simon TurnerHealthy Buildings International, Inc.

Richard A. VersenManville Technical Center

Davidge WarfieldNational Air Duct Cleaners Association

Lewis WeinstockForsyth County Environmental AffairsDepartment (Georgia)

John F. WelchSafe Buildings Alliance

Arthur E. WheelerWheeler Engineering Company

Jim H. WhiteCanada Mortgage and HousingCorporationW. Curtis WhiteAegis Environmental Management, Inc.

Alexander J. WillmanNational Energy Management Institute

Myra WinfieldVeterans Administration (Texas)

James E. WoodsCollege of Architecture and Urban Studies,Virginia Polytechnic Institute

Rita Cohen, of ICF, Inc., assisted in theproject management for the developmentof this document. Marie O'Neill, of TheBruce Company, provided editorial andcoordination assistance. EPA and NIOSHextend special thanks to Linda Berns,Terry Savage, and others at the firm ofBerns and Kay, Ltd. for their effort andenthusiasm in designing and producing thedocument under tight deadlines.

Acknowledgements xv

I I1 I111 I

Building Air Quality

BASICS

1 6 Printed on Recycled Paper

About This Document

BEFORE YOU BEGIN

The goal of this guidance document is tohelp you prevent indoor air qualityproblems in your building and resolve suchproblems promptly if they do arise. Itrecommends practical actions that can becarried out by facility staff, outsidecontractors, or both. The document willhelp you to integrate IAQ-related activitiesinto your existing organization and identifywhich of your staff have the necessaryskills to carry out those activities.

This is a long document. It would beconvenient if all of the ideas it containscould be summed up in a few shortrecommendations, such as: "check forunderventilation" and "isolate pollutantsources." However, such statementswould only be helpful to people who arealready familiar with indoor air qualityconcerns. If the owner's manual for yourcar said to check your pollution controlvalves every year, but didn't say how tofind out whether they were workingproperly, you would need either a moredetailed manual or the money to hire amechanic. Don't be discouraged by thenumber of pages in your hands. Once youbegin to understand the factors thatinfluence indoor air quality in yourbuilding, you can move from section tosection, reading what you need to know atthe moment and leaving the rest until later.

Some Basic Assumptions

EPA and NIOSH recognize that manyfactors influence how an individual owneror manager can put the information in thisguide to use. The skills of facility staff andthe uses of the building can vary widely,

affecting the types of IAQ problems thatare likely to arise and the most effectiveapproach to resolving those problems.

The assumptions used in preparing thisguide include:

The expense and effort required toprevent most IAQ problems is much lessthan the expense and effort required toresolve problems after they develop.Many IAQ problems can be preventedby educating facility management, staff,and occupants about the factors thatcreate such problems. When IAQproblems do arise, they can often beresolved using skills that are availablein-house.The basic issues and activities involvedin preventing and resolving IAQ prob-lems are similar for buildings of manydifferent designs and uses.If outside assistance is needed to solvean IAQ problem, the best results will beachieved if building owners and manag-ers are informed consumers.

How this Guide is Organized

This guide is divided into topic areasmarked by tabs. Tab I marks introductorymaterial directed toward all users of thedocument. Tab II is directed to buildingowners and facility managers who do nothave a current IAQ problem and want toprevent such problems from arising. If youcurrently have an indoor air qualityproblem, Tab III provides guidance tohelp resolve that problem. The appendicesmarked by Tab IV present informationthat may not be critical to resolving mostindoor air quality problems but could beuseful reading for additional background

17About This Document 1

on major IAQ topics. Abbreviated sampleforms are included throughout the text sothat readers can see what types of informa-tion can be collected using the forms pro-vided in this document. Tab V containsthe complete forms discussed in the text.These can be photocopied for use by youand your staff.

As you read this document, you will findthat some guidance points are repeated.This was intentional, as it allows you touse the sections on prevention, diagnosis,and mitigation as "stand-alone" guides.

Tab I: Basics

Section 2: Factors Affecting Indoor AirQuality

Indoor air quality is not a simple, easilydefined concept like a desk or a leakyfaucet. It is a constantly changing interac-tion of a complex set of factors. Four ofthe most important elements involved inthe development of indoor air qualityproblems are: a source of odors orcontaminants; a problem with the design oroperation of the HVAC system; a pathwaybetween the source and the location of thecomplaint; and the building occupants.

Read Section 2 for an introduction to thefactors that influence indoor air quality. Abasic understanding of these factors iscritical to investigating and resolving IAQproblems.

Section 3: Effective Communication

An effective communication system helpsfacility managers, staff, contractors, andoccupants to clarify their responsibilitiesand cooperate in identifying potential IAQproblems. Building occupants can bevaluable allies in resolving indoor air qual-ity problems. On the other hand, evensmall problems can have disruptive andpotentially costly consequences if occu-pants become frustrated and mistrustful.Effective communication is the key tocooperative problem-solving.

2 Section 1

18

Good communication can be promotedthrough a group that represents all of theinterested parties in the building. Manyorganizations have health and safety com-mittees that can fill this role. Section 3suggests ways to work productively withbuilding occupants to prevent IAQ prob-lems and to maintain good communicationduring IAQ investigations.

Tab II: Preventing IAOProblems

Section 4: Developing an IAQ Profile

An IAQ profile is a "picture" of buildingconditions from the perspective of indoorair quality. A review of construction andoperating records, combined with aninspection of building conditions, helps toreveal potential indoor air problems andidentify building areas that require specialattention to prevent problems in the future.Baseline data collected for the IAQ profilecan facilitate later investigations, shouldproblems arise. Section 4 suggests a three-stage approach to developing an IAQprofile and describes the products of eachstage.

Section 5: Managing Buildings for GoodIAQ

Many indoor air problems can be pre-vented by following common senserecommendations, such as: maintain goodsanitation, provide adequate ventilation,and isolate pollutant sources. Otherpreventive measures may require a carefulreview of job descriptions, contracts,supplies, and schedules. It is important todesignate an IAQ manager to bear respon-sibility for coordinating the effort in yourbuilding. Section 5 discusses key elementsto include in your IAQ management plan.

Tab III: Resolving IACI Problems

Section 6: Diagnosing IAQ Problems

Most IAQ investigations begin in responseto a complaint from one or more building

occupants. IAQ complaints can affectentire buildings or be limited to areas assmall as an individual work station. Thegoal of the investigation is to resolve thecomplaint without causing other problems.

Section 6 describes a variety of informa-tion-gathering strategies used to identifythe cause of an IAQ problem. This sectionprovides suggestions for in-house staffwho have been given the responsibility ofinvestigating the problem. It will also helpbuilding management to understand andoversee the activities of any outsideprofessionals who may be brought in toassist in the investigation.

Section 7: Mitigating IAQ Problems

The basic approaches to mitigating indoorair quality problems are: control ofpollutant sources; modifications to theventilation system; ail- cleaning; andcontrol of exposures to occupants. Suc-cessful mitigation often involves a combi-nation of these techniques.

Section 7 provides criteria for judgingpotential mitigation strategies and fordetermining whether a problem has beensolved. It includes brief descriptions ofcommon indoor air quality problems andpossible solutions.

Section 8: Hiring Professional Assis-tance to Solve an IAQ Problem

Indoor air quality is an emerging andinterdisciplinary field. Section 8 providesguidance in hiring professional assistanceif you decide that outside expertise isneeded to determine the cause of an IAQproblem.

Tab IV: Appendices

Appendix A: Common IAQMeasurements A General Guide

Appendix A describes measurementtechniques that are commonly used forIAQ investigations. If you are responsible

for developing an IAQ profile or investi-gating an IAQ complaint, Appendix Aprovides suggestions for collecting andinterpreting information on: temperatureand humidity; airflow patterns; carbondioxide; ventilation (outdoor) air quanti-ties; and commonly measured environmen-tal contaminants.

Appendix B: HVAC Systems and IAQ

Appendix B presents basic information onHVAC system designs and componentsand their effects on indoor air quality.This appendix is designed to accompanythe HVAC Checklists in Tab V.

Appendix C: Moisture, Mold andMildew

Appendix C discusses indoor moisture andits relationship to mold and mildewgrowth. The role of humidity in creatingmold and mildew problems is oftenmisunderstood because relative humidityreadings taken in the breathing zone of anoccupied space give little indication ofconditions at the wall and ceiling surfacesor in the wall cavities. This appendixdescribes ways in which to evaluate howmoisture may be causing indoor air qualityproblems and how successful differentmitigation measures may be in reducingthose problems.

Appendix D: Asbestos

Appendix D is a brief discussion ofasbestos. If asbestos is a concern in yourbuilding, this appendix and the Appendix Gsection will direct you to sources ofdetailed guidance.

Appendix E: Radon

Appendix E is a brief discussion of radon.To learn more about how to check forradon in your building, refer to thisappendix. Appendix G will direct you toother sources of information.

19About This Document 3

Appendix F: Glossary and Acronyms

Appendix F explains scientific andengineering terminology that may beunfamiliar to some readers.

Appendix G: Resources

Appendix G is intended for readers whowant to pursue more detailed informationabout indoor air quality. It includes thenames, addresses, and telephone numbersof Federal, State, and private sector organi-zations with interests related to IAQ, aswell as a list of selected publications.

Contaminant emission and movement inbuildings is an emerging field of study.Building owners, facility managers, andengineers are urged to keep abreast of newinformation through professional journalsand seminars in addition to relying on theguidance presented in this document.

Tab V: Indoor Air Quality Forms

Tab V contains a full set of the formsdescribed in Tabs II and III. Buildingmanagers are encouraged to reproduce anduse these blank forms. You may want tomodify elements of these forms to reflectconditions in your particular building.

4 Section 1

WARNING

Please note the following as you prepare touse this manual:

Modification of building functions toremedy air quality complaints may createother problems. A thorough understand-ing of all of the factors that interact tocreate indoor quality problems can helpto avoid this undesirable outcome.The guidance in this document is notintended as a substitute for appropriateemergency action in the event of ahazardous situation that may beimminently threatening to life or safety.The implementation of mitigationrecommendations reached as a result ofan indoor air quality evaluation shouldalways be done in accordance with locallaws and good practice. Changes to theoverall design and operation of thebuilding may necessitate the involve-ment of a registered professional engi-neer or other registered or certifiedprofessionals.In the event that medical records areutilized in the course of evaluating anIAQ problem, appropriate legal confi-dentiality must be maintained.

9 0

e Factors Affecting Indoor Air Quality

e indoor environment in any building isa result of the interaction between the site,climate, building system (original designand later modifications in the structure andmechanical systems), construction tech-niques, contaminant sources (buildingmaterials and furnishings, moisture,processes and activities within the building,and outdoor sources), and building occu-pants.

The following four elements are involvedin the development of indoor air qualityproblems:

Source: there is a source of contaminationor discomfort indoors, outdoors, or withinthe mechanical systems of the building.

HVAC: the HVAC system is not able tocontrol existing air contaminants and ensurethermal comfort (temperature and humidityconditions that are comfortable for mostoccupants).

Pathways: one or more pollutant pathwaysconnect the pollutant source to the occu-pants and a driving force exists to movepollutants along the pathway(s).

Occupants: building occupants are present.

It is important to understand the role thateach of these factors may play in order toprevent, investigate, and resolve indoor airquality problems.

SOURCES OF INDOOR AIRCONTAMINANTS

Indoor air contaminants can originatewithin the building or be drawn in fromoutdoors. If contaminant sources are notcontrolled, IAQ problems can arise, even ifthe HVAC system is properly designed andwell-maintained. It may be helpful to thinkof air pollutant sources as fitting into one of

the categories that follow. The examplesgiven for each category are not intended tobe a complete list.

Sources Outside Building

Contaminated outdoor airpollen, dust, fungal sporesindustrial pollutantsgeneral vehicle exhaust

Emissions from nearby sourcesexhaust from vehicles on nearby roadsor in parking lots or garagesloading docksodors from dumpstersre-entrained (drawn back into thebuilding) exhaust from the buildingitself or from neighboring buildingsunsanitary debris near the outdoor airintake

Soil gasradonleakage from underground fuel tankscontaminants from previous uses of thesite (e.g., landfills)pesticides

Moisture or standing water promotingexcess microbial growth

rooftops after rainfallcrawlspace

Equipment

HVAC systemdust or dirt in ductwork or othercomponentsmicrobiological growth in drip pans,humidifiers, ductwork, coilsimproper use of biocides, sealants, and/or cleaning compoundsimproper venting of combustionproductsrefrigerant leakage

2 IFactors Affecting Indoor Air Quality 5

2Four elementssources, the HVACsystem, pollutantpathways, andoccupants areinvolved in thedevelopment of !AOproblems.

Given our presentknowledge, it isdifficult to relatecomplaints ofspecific healtheffects to exposuresto specific pollutantconcentrations,especially since thesignificant exposuresmay be to low levelsof pollutant mixtures.

Non-HVAC equipmentemissions from office equipment (vola-tile organic compounds, ozone)supplies (solvents, toners, ammonia)emissions from shops, labs, cleaningprocesseselevator motors and other mechanicalsystems

Human Activities

Personal activitiessmokingcookingbody odorcosmetic odors

Housekeeping activitiescleaning materials and proceduresemissions from stored supplies or trashuse of deodorizers and fragrancesairborne dust or dirt (e.g., circulated bysweeping and vacuuming)

Maintenance activitiesmicroorganisms in mist from improp-erly maintained cooling towersairborne dust or dirtvolatile organic compounds from use ofpaint, caulk, adhesives, and otherproductspesticides from pest control activitiesemissions from stored supplies

Building Components and Furnishings

Locations that produce or collect dust orfibers

textured surfaces such as carpeting,curtains, and other textilesopen shelvingold or deteriorated furnishingsmaterials containing damaged asbestos

Unsanitary conditions and water damagemicrobiological growth on or in soiledor water-damaged furnishingsmicrobiological growth in areas ofsurface condensationstanding water from clogged or poorlydesigned drainsdry traps that allow the passage ofsewer gas

6 Section 22 2

Chemicals released from buildingcomponents or furnishings

volatile organic compounds orinorganic compounds

Other Sources

Accidental eventsspills of water or other liquidsmicrobiological growth due to floodingor to leaks from roofs, pipingfire damage (soot, PCBs from electricalequipment, odors)

Special use areas and mixed use buildingssmoking loungeslaboratoriesprint shops, art roomsexercise roomsbeauty salonsfood preparation areas

Redecoratinglremodelinglrepair activitiesemissions from new furnishingsdust and fibers from demolitionodors and volatile organic and inorganiccompounds from paint, caulk, adhesivesmicrobiologicals released from demoli-tion or remodeling activities

Indoor air often contains a variety ofcontaminants at concentrations that are farbelow any standards or guidelines foroccupational exposure. Given our presentknowledge, it is difficult to relate com-plaints of specific health effects to expo-sures to specific pollutant concentrations,especially since the significant exposuresmay be to low levels of pollutant mixtures.

HVAC SYSTEM DESIGN ANDOPERATION

The HVAC system includes all heating,cooling, and ventilation equipment servinga building: furnaces or boilers, chillers,cooling towers, air handling units, exhaustfans, ductwork, filters, steam (or heatingwater) piping. Most of the HVAC discus-sion in this document applies both to centralHVAC systems and to individual compo-nents used as stand-alone units.

A properly designed and functioningHVAC system:

provides thermal comfortdistributes adequate amounts of outdoorair to meet ventilation needs of allbuilding occupantsisolates and removes odors and con-taminants through pressure control,filtration, and exhaust fans

Thermal Comfort

A number of variables interact to deter-mine whether people are comfortable withthe temperature of the indoor air. Theactivity level, age, and physiology of eachperson affect the thermal comfort require-ments of that individual. The AmericanSociety of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE)Standard 55-1981 describes the tempera-ture and humidity ranges that are comfort-able for most people engaged in largelysedentary activities. That information issummarized on page 57. The ASHRAEstandard assumes "normal" indoorclothing. Added layers of clothing reducethe rate of heat loss.

Uniformity of temperature is importantto comfort. When the heating and coolingneeds of rooms within a single zonechange at different rates, rooms that areserved by a single thermostat may be atdifferent temperatures. Temperaturestratification is a common problem causedby convection, the tendency of light, warmair to rise and heavier, cooler air to sink. Ifair is not properly mixed by the ventilationsystem, the temperature near the ceilingcan be several degrees warmer than atfloor level. Even if air is properly mixed,uninsulated floors over unheated spacescan create discomfort in some climatezones. Large fluctuations of indoortemperature can also occur when controlshave a wide "dead band" (a temperaturerange within which neither heating norcooling takes place).

Radiant heat transfer may cause peoplelocated near very hot or very cold surfacesto be uncomfortable even though thethermostat setting and the measured airtemperature are within the comfort range.Buildings with large window areassometimes have acute problems of discom-fort due to radiant heat gains and losses,with the locations of complaints shiftingduring the day as the sun angle changes.Large vertical surfaces can also produce asignificant flow of naturally-convecting air,producing complaints of draftiness.Adding insulation to walls helps tomoderate the temperature of interior wallsurfaces. Closing curtains reduces heatingfrom direct sunlight and isolates buildingoccupants from exposure to windowsurfaces (which, lacking insulation, arelikely to be much hotter or colder than thewalls).

Humidity is a factor in thermal comfort.Raising relative humidity reduces theability to lose heat through perspiration andevaporation, so that the effect is similar toraising the temperature. Humidity ex-tremes can also create other IAQ problems.Excessively high or low relative humiditiescan produce discomfort, while high relativehumidities can promote the growth of moldand mildew. (See Appendix C.)

Ventilation to Meet OccupantNeeds

Most air handling units distribute a blendof outdoor air and recirculated indoor air.HVAC designs may also include units thatintroduce 100% outdoor air or that simplytransfer air within the building. Uncon-trolled quantities of outdoor air enterbuildings by infiltration through windows,doors, and gaps in the exterior construc-tion. Thermal comfort and ventilationneeds are met by supplying "conditioned"air (a blend of outdoor and recirculated airthat has been filtered, heated or cooled, andsometimes humidified or dehumidified).

2 3

Factors Affecting Indoor Air Quality 7

A number ofvariables, includingpersonal activitylevels, uniformity oftemperature, radiantheat gain or loss, andhumidity, interact todetermine whetherpeople are comfortablewith the temperatureof the indoor air.

The amount ofoutdoor airconsidered adequatefor proper ventilationhas variedsubstantially overtime. The currentguideline issued byASHRAE is Standard62-1989.

Large buildings often have interior("core") spaces in which constant coolingis required to compensate for heat gener-ated by occupants, equipment, andlighting, while perimeter rooms mayrequire heating or cooling depending onoutdoor conditions.

Two of the most common HVACdesigns used in modern public andcommercial buildings are constant volumeand variable air volume systems. Con-stant volume systems are designed toprovide a constant airflow and to vary theair temperature to meet heating andcooling needs. The percentage of outdoorair may be held constant, but is oftencontrolled either manually or automaticallyto vary with outdoor temperature andhumidity. Controls may include a mini-mum setting that should allow the systemto meet ventilation guidelines for outdoorair quantities under design conditions.

Variable air volume (VAV) systemscondition supply air to a constant tempera-ture and ensure thermal comfort by varyingthe airflow to occupied spaces. Most earlyVAV systems did not allow control of theoutdoor air quantity, so that a decreasingamount of outdoor air was provided as theflow of supply air was reduced. Somemore recent designs ensure a minimumsupply of outdoor air with static pressuredevices in the outdoor air stream. Addi-tional energy-conserving features such aseconomizer control or heat recovery arealso found in some buildings.

Good quality design, installation, andtesting and balancing are critically impor-tant to the proper operation of all typesof HVAC systems, especially VAVsystems, as are regular inspections andmaintenance. (See Appendix B for furtherdiscussion of HVAC system types.)

The amount of outdoor air consideredadequate for proper ventilation has variedsubstantially over time. The currentguideline issued by ASHRAE is ASHRAEStandard 62-1989. The building code thatwas in force when your building HVAC

8 Section 2

system was designed may well haveestablished a lower amount of ventilation(in cubic feet of outdoor air per minute perperson) than is currently recommended.(A table of outdoor air quantities recom-mended by ASHRAE is reproduced onpage 136 in Appendix B. Note that otherimportant aspects of the standard are notincluded in this table.)

Control of Odors andContaminants

One technique for controlling odors andcontaminants is to dilute them withoutdoor air. Dilution can work only ifthere is a consistent and appropriate flowof supply air that mixes effectively withroom air. The term "ventilation effi-ciency" is used to describe the ability ofthe ventilation system to distribute supplyair and remove internally generatedpollutants. Researchers are currentlystudying ways to measure ventilationefficiency and interpret the results of thosemeasurements.

Another technique for isolating odorsand contaminants is to design and operatethe HVAC system so that pressurerelationships between rooms are con-trolled. This control is accomplished byadjusting the air quantities that aresupplied to and removed from each room.If more air is supplied to a room than isexhausted, the excess air leaks out of thespace and the room is said to be underpositive pressure. If less air is suppliedthan is exhausted, air is pulled into thespace and the room is said to be undernegative pressure.

Control of pressure relationships iscritically important in mixed use buildingsor buildings with special use areas.Lobbies and buildings in general are oftendesigned to operate under positive pressureto prevent or minimize the infiltration ofunconditioned air, with its potential tocause drafts and introduce dust, dirt, andthermal discomfort. Without properoperation and maintenance, these pressure

2 4

differences are not likely to remain asoriginally designed.

A third technique is to use local exhaustsystems (sometimes known as dedicatedexhaust ventilation systems) to isolate andremove contaminants by maintainingnegative pressure in the area around thecontaminant source. Local exhaust can belinked to the operation of a particular pieceof equipment (such as a kitchen range) orused to treat an entire room (such as asmoking lounge or custodial closet). Airshould be exhausted to the outdoors, notrecirculated, from locations which producesignificant odors and high concentrationsof contaminants (such as copy rooms,bathrooms, kitchens, and beauty salons).

Spaces where local exhaust is used mustbe provided with make-up air and the localexhaust must function in coOrdination withthe rest of the ventilation system. Undersome circumstances, it may be acceptableto transfer conditioned air from reiativelyclean parts of a building to comparativelydirty areas and use it as make-up air for alocal exhaust system. Such a transfer canachieve significant energy savings.

Air cleaning and filtration devicesdesigned to control contaminants are foundas components of HVAC systems (forexample, filter boxes in ductwork) and canalso be installed as independent units. Theeffectiveness of air cleaning depends uponproper equipment selection, installation,operation, and maintenance. Cautionshould be used in evaluating the many newtechnological developments in the field ofair cleaning and filtration.

POLLUTANT PATHWAYS ANDDRIVING FORCES

Airflow patterns in buildings result fromthe combined action of mechanicalventilation systems, human activity, andnatural forces. Pressure differentialscreated by these forces move airbornecontaminants from areas of relativelyhigher pressure to areas of relatively lowerpressure through any available openings.

The HVAC system is generally thepredominant pathway and driving force forair movement in buildings. However, allof a building's components (walls, ceilings,floors, penetrations, HVAC equipment, andoccupants) interact to affect the distributionof contaminants.

For example, as air moves from supplyregisters or diffusers to return air grilles, itis diverted or obstructed by partitions,walls, and furnishings, and redirected byopenings that provide pathways for airmovement. On a localized basis, themovement of people has a major impact onthe movement of pollutants. Some of thepathways change as doors and windowsopen and close. It is useful to think of theentire building the rooms and theconnections (e.g., chases, corridors,stairways, elevator shafts) between themas part of the air distribution system.

Natural forces exert an importantinfluence on air movement between zonesand between the building's interior andexterior. Both the stack effect and windcan overpower a building's mechanicalsystem and disrupt air circulation andventilation, especially if the buildingenvelope is leaky.

Stack effect is the pressure driven flowproduced by convection (the tendency of

Factors Affecting Indoor Air Quality 9

2 5

Chases, crawlspaces, andother hidden spaces can beboth sources and pathwaysfor pollutants.

The basic principle ofair movement fromareas of relativelyhigher pressure toareas of relativelylower pressure canproduce manypatterns ofcontaminantdistribution.

warm air to rise). The stack effect existswhenever there is an indoor-outdoortemperature difference and becomesstronger as the temperature differenceincreases. As heated air escapes fromupper levels of the building, indoor airmoves from lower to upper floors, andreplacement outdoor air is drawn intoopenings at the lower levels of buildings.Stack effect airflow can transport contami-nants between floors by way of stairwells,elevator shafts, utility chases, or otheropenings.

Wind effects are transient, creating localareas of high pressure (on the windwardside) and low pressure (on the leewardside) of buildings. Depending on theleakage openings in the building exterior,wind can affect the pressure relationshipswithin and between rooms.

The basic principle of air movement fromareas of relatively higher pressure to areasof relatively lower pressure can producemany patterns of contaminant distribution,including:

local circulation in the room containingthe pollutant sourceair movement into adjacent spaces thatare under lower pressure (Note: Even iftwo rooms are both under positivepressure compared to the outdoors, oneroom is usually at a lower pressure thanthe other.)recirculation of air within the zonecontaining the pollutant source or inadjacent zones where return systemsoverlapmovement from lower to upper levels ofthe buildingair movement into the building througheither infiltration of outdoor air orreentry of exhaust air

Air moves from areas of higher pressureto areas of lower pressure through anyavailable openings. A small crack or holecan admit significant amounts of air if thepressure differentials are high enough(which may be very difficult to assess).

10 Section 2 28

Even when the building as a whole ismaintained under positive pressure, there isalways some location (for example, theoutdoor air intake) that is under negativepressure relative to the outdoors. Entry ofcontaminants may be intermittent, occur-ring only when the wind blows from thedirection of the pollutant source. Theinteraction between pollutant pathways andintermittent or variable driving forces canlead to a single source causing IAQcomplaints in areas of the building that aredistant from each other and from thesource.

BUILDING OCCUPANTS

The term "building occupants" is generallyused in this document to describe peoplewho spend extended time periods (e.g., afull workday) in the building. Clients andvisitors are also occupants; they may havedifferent tolerances and expectations fromthose who spend their entire workdays inthe building, and are likely to be moresensitive to odors.

Groups that may be particularly suscep-tible to effects of indoor air contaminantsinclude, but are not limited to.

allergic or asthmatic individualspeople with respiratory diseasepeople whose immune systems aresuppressed due to chemotherapy,radiation therapy, disease, or othercausescontact lens wearers

Some other groups are particularlyvulnerable to exposures of certainpollutants or pollutant mixtures. Forexample, people with heart disease may bemore affected by exposure at lower levelsof carbon monoxide than healthyindividuals. Children exposed to environ-mental tobacco smoke have been shown tobe at higher risk of respiratory illnessesand those.exposed to nitrogen dioxide havebeen shown to be at higher risk fromrespiratory infections.

Because of varying sensitivity amongpeople, one individual may react to aparticular IAQ problem while surroundingoccupants have no ill effects. (Symptomsthat are limited to a single person can alsooccur when only one work station receivesthe bulk of the pollutant dose.) In othercases, complaints may be widespread.

A single indoor air pollutant or problemcan trigger different reactions in differentpeople. Some may not be affected at all.Information about the types of symptomscan sometimes lead directly to solutions.However, symptom information is morelikely to be useful for identifying the timingand conditions under which problemsoccur.

Types of Symptoms andComplaints

The effects of IAQ problems are often non-specific symptoms rather than clearlydefined illnesses. Symptoms commonlyattributed to IAQ problems include:

headachefatigueshortness of breathsinus congestioncoughsneezingeye, nose, and throat irritationskin irritationdizzinessnausea

All of these symptoms, however, may alsobe caused by other factors, and are notnecessarily due to air quality deficiencies.

"Health" and "comfort" are used todescribe a spectrum of physical sensations.For example, when the air in a room isslightly too warm for a person's activitylevel, that person may experience milddiscomfort. If the temperature continues torise, discomfort increases and symptomssuch as fatigue, stuffiness, and headachescan appear.

Some complaints by building occupantsare clearly related to the discomfort end ofthe spectrum. One of the most commonIAQ complaints is that "there's a funnysmell in here." Odors are often associatedwith a perception of poor air quality,whether or not they cause symptoms.Environmental stressors such as improperlighting, noise, vibration, overcrowding,ergonomic stressors, and job-relatedpsychosocial problems ,(such as job stress)can produce symptoms that are similar tothose associated with poor air quality.

The term sick building syndrome (SBS)is sometimes used to describe cases inwhich building occupants experience acutehealth and comfort effects that are appar-ently linked to the time they spend in thebuilding, but in which no specific illness orcause can be identified. The complaintsmay be localized in a particular room orzone or may be widespread throughout thebuilding. Many different symptoms havebeen associated with SBS, includingrespiratory complaints, irritation, andfatigue. Analysis of air samples often failsto detect high concentrations of specificcontaminants. The problem may be causedby any or all of the following:

the combined effects of multiplepollutants at low concentrationsother environmental stressors(e.g., overheating, poor lighting, noise)ergonomic stressorsjob-related psychosocial stressors(e.g., overcrowding, labor-managementproblems)unknown factors

Building-related illness (BRI) is a termreferring to illness brought on by exposureto the building air, where symptoms ofdiagnosable illness are identified (e.g.,certain allergies or infections) and can bedirectly attributed to environmental agentsin the air. Legionnaire's disease andhypersensitivity pneumonitis are examplesof BRI that can have serious, even life-threatening consequences.

2 '7Factors Affecting Indoor Air Quality 11

Environmentalstressors such asimproper lighting,noise, vibration,overcrowding,ergonomic stressors,and job-relatedpsychosocialproblems (such as jobstress) can producesymptoms that aresimilar to thoseassociated with poorair quality.

A small percentage of the populationmay be sensitive to a number of chemicalsin indoor air, each of which may occur atvery low concentrations. The existence ofthis condition, which is known as multiplechemical sensitivity (MCS), is a matter ofconsiderable controversy. MCS is notcurrently recognized by the major medicalorganizations, but medical opinion isdivided, and further research is needed.The applicability of access for the disabledand worker's compensation regulations topeople who believe they are chemicallysensitive may become concerns for facilitymanagers.

2 8

12 Section 2

Sometimes several building occupantsexperience rare or serious health problems(e.g., cancer, miscarriages, Lou Gehrig'sdisease) over a relatively short time period.These clusters of health problems areoccasionally blamed on indoor air quality,and can produce tremendous anxietyamong building occupants. State or localHealth Departments can provide adviceand assistance if clusters are suspected.They may be able to help answer keyquestions such as whether the apparentcluster is actually unusual and whether theunderlying cause could be related to IAQ.

Effective Communication

This section discusses establishing and

maintaining a communication system thatcan help prevent indoor air quality

problems and resolve problems coopera-

tively if they do arise. If you are currentlyresponding to an indoor air quality

complaint, you may want to skip ahead tothe discussion of Communicating toResolve IAQ Problems on page 15.

COMMUNICATING TO PREVENTIAQ PROBLEMS

Effective communication can encourage

buildine occupants to improve their workenvironment through positive contribu-tions. The following objectives should bekept in mind while reviewine and revisingyour current approach to communicatingwith occupants:

provide accurate information about

factors that affect indoor air qualityclarify the responsibilities of each party(e.g., building management, staff, ten-ants, contractors)

establish an effective system for loggingand responding to complaints should

they occur

Provide Accurate Information

Many indoor air quality problems can beprevented if staff and building occupants

understand how their activities affect IAQ.You may already have a health and safety

committee functioning to promote good

working conditions. If so, it is easy to addindoor air quality to their list of concerns.If you do not have a health and safety

committee, consider establishing one orsetting up a joint management-tenant IAQ

task force. Whatever its official designa-tion, such a group can help to disseminate

information about indoor air quality, bring

potential problems to the attention ofbuilding staff and management, and fostera sense of shared responsibility for

maintaining a safe and comfortable indoorenvironment.

The group will be most sticcessful if itrepresents the diverse interests in thebuilding, including:

building ownerbuilding managerfacility personnelhealth and safety officials

tenants and/or other occupants who arenot facility staffunion representatives (or other worker

representatives)

Clarify Responsibilities

It is important to define the responsibilitiesof building management, staff, andoccupants in relation to indoor air quality.These responsibilities can be formalized byincorporating them into documents such asemployee manuals or lease agreements.

111. IN*

IRV 4

Effective Communication 13 0 9

The occupant in this roomcovered the supply air ventswith papers. Whether thiswas done to reduce uncom-fortable drafts or to providemore shelf space, the resultcan disrupt the air flow, notonly through this room butelsewhere in the building.By tampering with the airhandling system, occupantscan unintentionally causecomplaints in other areas.

'itoxt

Use of space: Educate occupants about thepermitted uses and maximum occupancy ofdifferent areas within the building andmake sure that appropriate ventilation isprovided for the activities that are permit-ted. Indoor air quality complaints oftenarise in mixed-use buildings. For example,kitchen staff expect food odors as part oftheir work, but nearby office workers mayfind cooking odors distracting and unpleas-ant. Problems can also arise when oldtenants leave and new arrivals introducenew uses of the building.

Occupancy Rate: Inform occupants aboutthe importance of keeping the buildingmanagement informed about significantchanges in the number of people regularlyusing particular areas of the building. Theventilation systems in buildings aredesigned and operated to supply air to

MANAGEMENT AND OCCUPANT COOPERATIONON INDOOR AIR QUALITY

The State of Wisconsin's "Quality Building Management" systemhas helped to unite the diverse interests involved in operatingand using State office buildings. Tenants and facility personnelvolunteered to serve on teams, working cooperatively to improvethe quality of the indoor environment.

Each team was assigned a specific area for which it drafted"Ideal Building Standards." Air quality was one such area;others included elevators, rest rooms, and work spaces. The IAQteams were trained in conducting research; toured mechanicalrooms to achieve a better understanding of building operations;read articles; and listened to presentations on IAQ, ventilation,and related topics.

The proposed "Ideal Building Standards" were reviewed withother tenants and then used as a basis for Quality ImprovementPlans. Some elements of the Quality Improvement Plans identifyresponsibilities of the tenants, such as adopting good house-keeping practices to improve the work environment and facilitatecleaning. Responsibilities identified as belonging to buildingmanagement are reflected in work plans and budget decisions.

Since implementation of this management system, interactionsbetween building management and tenants have improved.Tenants actively seek out management staff to discuss concerns.However, they are also more willing to review their own actionswhen looking for potential causes of IAQ problems.

14 Section 3 3 0

projected ranges of occupants. If theoccupancy rate becomes a problem, it maybe helpful to refer to a standard referencesuch as ASHRAE Standard 62-1989 toshow occupants that keeping occupancywithin the ventilation capacity serves thegoal of providing a quality work environ-ment and is not an arbitrary decision bybuilding management.

Modifications: Review plans that mayinvolve increases in the number of occu-pants, relocation of walls or partitions,installation of new equipment, or changesin the use of space. Building owners,facility managers, and occupants shareresponsibility for monitoring new equip-ment installation and changes in the use ofspace. The review process allows potentialindoor air quality problems to be identifiedso that the HVAC system can be modifiedas needed. Only authorized maintenancepersonnel should adjust air supply orexhaust vents; however, if occupants areexpected to follow such a "hands-off"policy, facility management must respondpromptly to 1AQ complaints.

iVotification of planned activities:Establish a procedure for informing tenantsbefore the start of activities that produceodors or contaminants (e.g., maintenance,pest control, repair, remodeling,redecorating).

Establish a System forResponding to Complaints

Many organizations have establishedprocedures for responding to occupantcomplaints that can be modified to includeindoor air quality concerns. To avoidfrustrating delays. building occupants needto know how to express their complaintsabout IAQ. Most importantly, they need toknow how to locate responsible staff andwhere to obtain complaint forms. Thisinformation can be posted on bulletinboards, circulated in memos or newsletters.or publicized by some other means.

Complaints should be handledpromptly, with every incident givenserious attention. It is advisable toestablish a recordkeeping system thatcross-references documentation oncomplaints with records of equipmentoperation and maintenance. Therecordkeeping system can help to resolvecomplaints by collecting information in aform that highlights patterns of problems(for example, complaints that occur at aregular time of day or in the same area ofthe building). The IAQ Complaint Formand Incident Log shown here and on thefollowing page (and also reproduced inTab V) can be used to track complaintsrelated to the indoor environment.

COMMUNICATING TO RESOLVEIACI PROBLEMS

In many cases, building managers may bealerted to potential indoor air qualityproblems by complaints from occupants.The complaints can be vague, to the effectthat one or more people feel "sick" or"uncomfortable" or that someone hasnoticed an unusual odor. They may bespecific, blaming a particular material asthe cause of discomfort or health problems.People are usually reacting to a realproblem, so their complaints should betaken seriously. However, they mayattribute their symptoms to the wrongcause, so their theories about the problemshould be heard respectfully but weighedcautiously.

Indoor air quality problems cansometimes be identified and resolvedquickly. On other occasions, complaintsoriginate from the interaction of severalvariables, and detailed investigation maybe necessary in order to resolve theproblem.

The Importance of Respondingto IAQ Complaints

Listening and responding to buildingoccupants is critical to achieving a

Sample FormIndoor Air Quality Complaint Form

This form should be used if your complaint may be related toindoor air quality. Indoor air quality problems include concernswith temperature control, ventilation, and air pollutants. Yourobservations can help to resolve the problem as quickly as possible.Please use the space below to describe the nature of the complaintand any potential causes.

We may need to contact you to discuss your complaint. What is thebest time to reach you?

So that we can respond promptly, please return this form to:

IAQ Manager or Contact Person

successful resolution of indoor air qualitycomplaints. IAQ complaints may begrounded in poor indoor air quality,thermal conditions, noise, glare, or evenjob stresses. However, it is in the buildingmanager's best interest to respond to allcomplaints about the indoor environmentpromptly and seriously and to establishcredibility through open communicationwith building occupants. The biggestmistake that building managers can makein the face of an IAQ complaint is tounderestimate the problems that can resultif building occupants believe that no actionis being taken or that important informa-tion is being withheld. Without opencommunication, any IAQ problem canbecome complicated by anxiety, frustra-tion, and distrust, delaying its resolution.

Paying attention to communication, aswell as problem-solving, helps to ensure

Effective Communication 15

SEECOMPLETEFORMPAGE 181

31

Sample FormIncident Log

Investigation Record(check the forms that were used)

FileNumber

Date ProblemLocation

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Outcome /Comments

Log Entry By(initials)


The messages toconvey are thatmanagement believesit is important toprovide a healthy andsafe building, thatgood indoor airquality is an essentialcomponent of ahealthful indoorenvironment, and thatcomplaints aboutindoor air quality aretaken seriously.

the support and cooperation of buildingoccupants as the complaint is investigatedand resolved. The messages to convey arethat management believes it is important toprovide a healthy and safe building, thatgood indoor air quality is an essentialcomponent of a healthful indoor environ-ment, and that complaints about indoor airquality are taken seriously.

Communications, whether they occur inconversations or in writing, should includethe following information:

what types of complaints managementhas receivedmanagement's policy in regard toproviding a healthy and safe environ-ment and responding to occupantcomplaintswhat management has done to date (e.g.,collecting data, responding to theproblem)what management plans to do in order tofurther investigate and correct theproblem (including the fact that outsideconsultants have been called in. if theyhave been)the names and telephone numbers ofappropriate facility management.

16 Section 3

medical, or health and safety staff towhom the occupants should turn if theyhave additional complaints or questions,or if they have information that may helpin resolving the complaints

Maintaining the Lines ofCommunication

Make certain that occupants know how tocontact the responsible personnel who canreceive and respond to IAQ complaints.Tenants may also have an internal systemfor channeling complaints, for examplethrough a health and safety representative,supervisor, or company doctor.

Indoor air quality complaints that canbe resolved quickly and that involve smallnumbers of people (e.g., annoying butharmless odors from an easily-identifiedsource) can be handled matter-of-factlylike other minor problems without riskingconfusion and bad feeling among otherbuilding occupants. Communicationbecomes a more critical issue when thereare delays in identifying and resolving theproblem and when serious health concernsare involved.

32

If the problem seems to be widespreador potentially serious, it is advisable towork with your health and safety commit-tee. If you do not have a health and safetycommittee, consider forming one, orestablishing a joint management-tenantIAQ task force. (See the discussion onpage 13.)

Productive relations will be enhanced ifoccupants are given basic informationduring the process of investigation andmitigation. Potential critics can becomeallies if they are invited to be part of theproblem-solving process and becomebetter educated about 1AQ and buildingoperations. Building managers may beunderstandably reluctant to share testresults or consultants' reports with theirtenants or employees, but secrecy in suchmatters can backfire if information leaksout at a later time.

Building management staff can beencouraged to talk directly with occupantsboth at the time a complaint occurs andlater during a diagnostic investigation.Their observations about patterns ofsymptoms or building conditions mayprovide helpful information.

Confidentiality of records can beimportant to occupants, especially if theyare concerned that IAQ complaints willlead to negative reactions from theiremployers. There may be legal penaltiesfor violating confidentiality of medicalrecords. By reassuring occupants thatprivacy will be respected, investigators aremore likely to obtain honest and completeinformation.

It is advisable to explain the nature ofinvestigative activities, so that rumors andsuspicions can be countered with factualinformation. Notices or memoranda canbe delivered directly to selected occupantsor posted in general use areas. Newsletterarticles or other established communica-tion channels can also be used to keepbuilding occupants up-to-date.

Problems can arise from saying eithertoo little or too much. Premature releaseof information when data-gathering is stillincomplete can produce confusion,frustration, and mistrust at a later date.Similar problems can result from incorrectrepresentation of risk assuming theworst case (or the best). However, ifprogress reports are not given, people maythink nothing (or something terrible) ishappening. It is good practice to cleareach piece of information with the facilitymanager, building owner, or legal counsel.Management should attempt to be factualand to the point when presenting informa-tion such as:

the definition of the complaint areabased upon the location and distributionof complaints (this may be revised as theinvestigation progresses)the progress of the investigation,including the types of information thatare being gathered and ways thatoccupants can helpfactors that have been evaluated andfound not to be causing or contributingto the problemhow long the investigation might takeattempts that are being made to improveindoor air qualitywork that remains to be done and theschedule for its completion

Vague discomfort, intermittent symp-toms, and complex interactions of jobstress with environmental factors, whichmake IAQ problems difficult to investi-gate, can also obscure the effects ofmitigation efforts. Even after the propermitigation strategy is in place, it may takedays or weeks for contaminants to dissi-pate and symptoms to disappear. Ifbuilding occupants are informed that theirsymptoms may persist for some time aftermitigation, the inability to bring instantrelief is less likely to be seen as a failure.

33Effective Communication 17

If the problem seemsto be widespread orpotentially serious, itis advisable to workwith your health andsafety committee. Ifyou do not have ahealth and safetycommittee, considerforming one, orestablishing a jointmanagement-tenantIACI task force.


4

'1

1 PREVENTING IAO PROBLEMS/

* Printed on Recycled Paper

Developing an IAQ Profile

An IAQ profile is a description of thefeatures of the building structure, function,and occupancy that impact indoor airquality. When you have completed theIAQ profile, you should have an under-standing of the current status of air qualityin the building and baseline information onthe factors that have a potential for causingproblems in the future.

The IAQ profile can help buildingmanagement to identify potential problemareas and prioritize budgets for mainte-nance and future modifications. Combinedwith information on lighting, security, andother important systems, it can become anowner's manual that is specific to yourbuilding and that will serve as a referencein a variety of situations.

The key questions to answer whiledeveloping the IAQ profile are:

How was this building originallyintended to function? Consider thebuilding components and furnishings,mechanical equipment (HVAC and non-HVAC), and the occupant populationand associated activities.Is the building functioning as designed?Find out whether it was commissioned.Compare the information from thecommissioning to its current condition.What changes in building layout and usehave occurred since the original designand construction? Find out if the HVACsystem has been reset and retested toreflect current usage.What changes may be needed to preventIAQ problems from developing in thefuture? Consider potential changes infuture uses of the building.

After reading this manual to develop afeel for the issues involved in maintaininggood indoor air quality in a building, thedevelopment of an IAQ profile shouldbecome a priority. The process ofdeveloping an IAQ profile should requireonly a modest effort, from a few days to afew weeks of staff time, depending on thecomplexity of your building and theamount of detailed information collected.The work can be done in pieces over alonger period, if necessary, to fit into abuilding manager's busy schedule.

Over time, it is desirable to make someactual measurements of airflow, tempera-ture, relative humidity, carbon dioxide(CO2), and/or pressure differentials (e.g., ineach of the air handling zones or other sub-areas of the building). These measure-ments provide far better information oncurrent conditions than can be obtainedfrom the plans and specifications, even ifas-built records are available.

In addition, few buildings have beenadequately commissioned, so the systemmay never have delivered the airflowsshown on the design drawings. In theevent of litigation around future IAQcomplaints, the value of the IAQ profile asa resource document will be enhanced byreal-world measurements. (Refer toAppendix G and the ASHRAE standard oncommissioning. The EPA document ondesigning for good indoor air quality,which is due to be published in 1992, willcontain a more complete discussion of theprocess of commissioning buildings.)

3 5

Developing an IAQ Profile 19

FIGURE 4-1: Developing an IAG Profile SKILLS REQUIRED TO CREATEAN IAQ PROFILE

START

1. Collect andReview ExistingRecords

Review design,construction, andoperating documents

Check HVAC mainte-nance records againstequipment lists

Review complaintrecord

V2. Conduct a

WalkthroughInspection of theBuilding

Talk with staff andother occupants

Look for IAO problemindicators

3. Collect DetailedInformation

HVAC systemcondition andoperation

Pollutant pathways

Pollutant sources

Occupants

PRODUCTS

Description of HVAC systemdesign and operation; set ofoperating instructions, manuals

Set of maintenance and calibrationrecords

Inventory of locations whereoccupancy, equipment, or buildinghave changed

Inventory of complaint locations

List of responsible staff and/orcontractors; evidence of training;job descriptions

Identification of areas wherepositive or negative pressuresshould be maintained (sketchplan)

Record of locations that needmonitoring or correction

Inventory of HVAC systemcomponents needing repair,adjustment or replacement

Record of control settings andoperating schedules

Completed plan showing airflowdirections or pressure differen-tials in significant areas

Inventory of significantpollutant sources and theirlocations

Set of Material Safety DataSheets for supplies andhazardous substances that arestored or used in the building

Zone/Room Record

Yes

No

Develop an IAD management plan (see Section 5)

20 Section 4

Many of the resources necessary for theIAQ profile should already be on handwithin your organization. Additionalinformation can be collected by the staffperson or persons who have the followingskills:

basic understanding of HVAC systemoperating principlesability to read architectural and mechani-cal plans and understand manufacturer'scatalog data on equipmentability to identify items of officeequipmentability to work cooperatively withbuilding occupants and gather informa-tion about space usageability to collect information aboutHVAC system operation, equipmentcondition, and maintenance schedulesauthority to collect information fromsubcontractors about work schedulesand materials used (particularly cleaningand pest control activities)ability to understand the practicalmeaning of the information contained inthe Material Safety Data Sheets(MSDSs)

If direct measurements are to beincluded in the IAQ profile, the staffshould have the tools and training to makethe following measurements (see AppendixA for guidance on air sampling):

air volumes at supply diffusers andexhaust grillesCO, concentrationtemperaturerelative humiditypressure differentialsassessment of thermal and ventilationload requirements

Section 8 provides guidance on hiringIAQ professionals if you prefer to useoutside expertise to develop your IAQprofile.

STEPS IN AN IAQ PROFILE

The information needed for an 1AQ profileis similar to that which is collected whensolving indoor air quality problems, butincludes the entire building rather thanfocusing on areas that may have caused anidentified problem. The IAQ profileshould be an organized body of recordsthat can be referred to in planning forrenovations, negotiating leases andcontracts, or responding to future com-plaints.

The process of gathering informationfor the IAQ profile can be divided intothree major stages:I. Collect and review existing records.2. Conduct a walkthrough inspection ofthe building.3. Collect detailed information on theHVAC system, pollutant pathways,pollutant sources, and buildingoccupancy.

The first two stages should be carriedout as quickly as possible, but the thirdstage can be handled as time allows so thatit does not interfere with other staffresponsibilities.

1. Collect and Review ExistingRecords

Review construction and operatingdocuments

Collect any available documents thatdescribe the construction and operation ofthe building: architectural and mechanicalplans, specifications, submittals, sheetmetal drawings, commissioning reports,adjusting and balancing reports, inspectionrecords, and operating manuals. Manybuildings may lack some or all of thesedocuments. If there are no commissioningreports or balancing reports, actual venti-lation quantities may be quite differentfrom those indicated on mechanical design

PRODUCTS OF THE REVIEW OF EXISTING RECORDS

a description of the HVAC system design and operation(e.g., original plans and specifications with changes indi-cated or new sketch plans and notes, commissioning reports,testing and balancing reports)a set of operating instructions, and maintenance and calibra-tion records for HVAC system components (e.g., fans,dampers, filters, chillers, boilers, and control systems)an inventory of locations where architectural or engineeringmodifications have taken placean inventory of locations in which current occupancy orHVAC system operation represents a change from theoriginal designan inventory of locations where complaints have beencommon in the past

drawings. If there are no operating ormaintenance manuals for HVAC equip-ment, it is difficult for staff to carry out anadequate preventive maintenance program.

Study the original architectural andmechanical design so that you understandthe building's layout and intended func-tions. Identify and note locations in whichchanges in equipment or room usage createa potential for indoor air quality problemsand give them special attention during thewalkthrough inspection.

Items of interest and the questions theysuggest could include the following:

Commissioning reports

Was the building properly commissionedwhen it was first constructed, includingtesting and balancing of the HVACsystem?

Operating manuals

Do staff members understand how theHVAC equipment is intended to operate?

Remodeled areas

Has the HVAC system layout beenchanged to accommodate new walls,rearranged partitions. or similar architec-tural modifications?

3 7Developing an 1AQ Profile 21

Addition, removal, or replacement ofHVAC equipment

Where the original equipment has beenreplaced, do the newer units have thesame capacity as the originals?Has new equipment been properlyinstalled and tested? Where equipmenthas been removed, is it no longerneeded?

Changes in room use

Is there a need for additional ventilation(supply and/or exhaust) due to increasedoccupant population or new activitieswithin any area of the building?Have new items of equipment (non-HVAC) been provided with local exhaustwhere needed? Look for unusual typesor quantities of equipment such as copymachines or computer terminals.

Check HVAC maintenance recordsagainst equipment lists

Collect your existing maintenance andcalibration records and check them againstthe construction documents (e.g., equip-ment lists and mechanical plans). Seewhether all components appear to bereceiving regular attention. Equipment that

PRODUCTS OF THE WALKTHROUGH INSPECTION

At the end of the walkthrough inspection, you should have:

List of staff (and contractors) with responsibilities that couldaffect IAQ, including contact information:

names, telephone numbers, job descriptionsnotes on training and experience of building staff

Notes on the schedules and procedures used in:facility operation and maintenance

housekeepingpest control

Sketch plan with notes showing:pressure relationships between special use areas and

surrounding roomslocations in which general indicators of IAQ problems showthe need for close monitoring or corrective action

22 Section 4 3 8

has been installed in inaccessible or out-of-the-way locations is frequently overlookedduring routine maintenance. This isparticularly true of items such as filterboxes and small capacity exhaust fans.

Review records of complaints

If there is an organized record of pastoccupant complaints about the buildingenvironment, review those complaints toidentify building areas that deserveparticular attention.

2. Conduct a WalkthroughInspection of the Building

The intent of the walkthrough inspection isto acquire a good overview of occupantactivities and building functions and tolook for IAQ problem indicators. Nospecific forms are suggested for this stageof 1AQ profile development. However,the investigator should have a sketch planof the building, such as a small floor planshowing fire exits, so that his or her notescan be referenced to specific locations.

Detailed measurements of temperature,humidity, airflow, or other parameters aremore appropriate to a later stage of profiledevelopment. However, chemical smokecan be used to observe airflow patterns andpressure relationships between special useareas or other identified pollutant sourcesand surrounding rooms. Odors in inappro-priate locations (e.g., kitchen odors in alobby) may indicate that ventilation systemcomponents require adjustment or repair.(See Appendix A for further discussion ofthe use of chemical smoke.)

The value of IAQ ventilation measure-ment tools to your operation will grow asyou become more familiar with handlingindoor air quality concerns. For example.if you do not own a direct-reading carbondioxide monitor, it is not necessary toacquire one for the IAQ profile. Thosewho already have access to this type ofinstrument can take readings during thewalkthrough as a way to obtain baseline

information about normal operatingconditions or identify problem locations.If you begin to suspect that underventila-tion is a consistent problem. you maydecide that it would be helpful to obtainmore ventilation monitoring equipment.(See Appendix A for further discussion ofcarbon dioxide and other ventilationmeasurements.)

Talk with staff and other occupants

A walkthrough inspection provides anopportunity to introduce facility staff andother building occupants to the topic ofindoor air quality and to understand currentstaff (and contractor) responsibilities inrelation to housekeeping and maintenanceactivities. Advance notice of the inspec-tion will make it seem less intrusive andmay encourage staff and other occupants toremember important information.

Discussion of routine activities in thebuilding will help to clarify elements thatshould be included in the IAQ manage-ment plan. Ask staff members about theirjob responsibilities, training and experi-ence. It will be helpful to meet withresponsible staff and contractors todiscuss:

Facility operation and maintenance(e.g., HVAC, plumbing, electric, interiormaintenance)

HVAC operating schedule (e.g., occu-pied/unoccupied cycles)HVAC maintenance schedule (e.g., filterchanges, drain pan maintenance)use and storage of chemicalsschedule of shipping and receiving,handling of vehicles at loading dockscheduling and other procedures forisolating odors, dust, and emissions frompainting, roof repair, and other contami-nant-producing activitiesbudgeting (e.g., including staff influenceon budget decisions)

Housekeeping

cleaning scheduletrash storage and schedule of refuseremovaluse and storage of chemicals

Pest control

schedule and location of pesticideapplicationsuse and storage of chemicalspest control activities other than use ofpesticides

Look for IAQ problem indicators

The walkthrough inspection can be used toidentify areas with a high potential for 1AQproblems. The following are generalindicators of IAQ problems:

odorsdirty or unsanitary conditions (e.g.,excessive dust)visible fungal growth or moldy odors(often associated with problem of toomuch moisture)

3 9Developing an IAQ Profile 23

waif

Maintenance is more likelyto be performed on aroutine basis when there isgood access to HVACequipment such as thatshown in this photo.

Building occupants who areuncomfortable may try toimprove the situation bythemselves. The small fansshown above indicate an aircirculation or thermaldiscomfort problem. Theirony of this situation is thatthe fan motors add heat tothe air.

sanitary conditions in equipment such asdrain pans and cooling towerspoorly-maintained filterssigns of mold or moisture damage atwalls (e.g., below windows, at columns,at exterior corners), ceilings, and floorsstaining and discoloration (Note: Makesure that stains are removed after leaksare repaired so that there will be visibleevidence if the leak recurs.)smoke damage (Note: If a fire hasoccurred involving electrical equipment,determine whether PCBs (polychlori-nated biphenyls) may have been releasedfrom the equipment.)presence of hazardous substancespotential for soil gas entry (e.g., unsealedopenings to earth, wet earth smells)unsanitary mechanical room, or trash orstored chemicals in mechanical roomunusual noises from light fixtures ormechanical equipment

In addition to these general indications,some common problems deserve mention:

24 Section 4 4 0

Inadequate maintenance: Look for leaksof oil, water, or refrigerants around HVACequipment. Also be aware of signals suchas unreplaced burned-out light bulbs in fanchambers and staff members who havedifficulty locating specific pieces ofequipment. Dry drain traps can also causeindoor air quality problems. If traps arenot kept charged with liquid, they could beallowing sewer gas to enter occupiedspaces.

Signs of occupant discomfort: Noticeuneven temperatures, persistent odors(including tobacco smoke), drafts, sensa-tions of stuffiness. You may find thatoccupants are attempting to compensatefor an HVAC system that doesn't meettheir needs. Look for propped-opencorridor doors, blocked or taped-updiffusers, popped-up ceiling tiles, peopleusing individual fans/ heaters or wearingheavier (or lighter) clothing than normal.

Overcrowding: Future occupant density isestimated when the ventilation system for abuilding is designed. When the actualnumber of occupants approaches orexceeds this occupant design capacity,managers may find that IAQ complaintsincrease. At that point, the outdoor airventilation rate will have to be increased.However, the ventilation and coolingsystems may not have sufficient capacityto handle the increased loads from thecurrent use of the space.

Blocked airflow: Check for under-ventilation caused by obstructed vents,faulty dampers or other FIVAC systemmalfunctions, or from problems within theoccupied space. Furniture, papers, or othermaterials can interfere with air movementaround thermostats or block airflow fromwall or floor-mounted registers. If officecubicles are used, a small space (i.e., twoto four inches) between the bottom of thepartitions and the floor may improve aircirculation.

Ceiling plenums: Lift a ceiling tile andexamine the plenum for potential prob-

lems. Walls or full-height partitions thatextend to the floor above can obstruct ordivert air movement in ceiling plenumsunless transfer grilles have been provided.If fire dampers have been installed toallow air circulation through walls orpartitions, confirm that the dampers areopen. Construction debris and damaged orloose material in the plenum area maybecome covered with dust and can releaseparticles and fibers.

Heat sources: Be aware of areas thatcontain unusual types or quantities ofequipment such as copy machines orcomputer terminals. Also look forinstances of over-illumination. Highconcentrations of electrical fixtures andequipment can overwhelm the ventilationand cooling systems.

Special use areas: Confirm that theHVAC system maintains appropriatepressure relationships to isolate andcontain odors and contaminants in mixed-use buildings and around special use areas.Examples of special use areas includeattached parking garages, loading docks,print shops, smoking lounges, janitorialclosets, storage areas, and kitchens.

Improperly located vents, exhausts andair intakes: Check the outdoor air intakesto see whether they are located nearcontaminant sources (e.g., plumbing vents,exhaust outlets, dumpsters, loading docks,or other locations where vehicles idle).

Unsanitary mechanical rooms: See if thespace containing the HVAC system isclean and dry. Examples of problemsinclude: cleaning or other maintenancesupplies stored in mechanical room; dustand dirt buildup on floors and equipment;moisture in mechanical room because ofinadequate insulation, lack of conditionedair, or failure to provide for air movement.Unsanitary conditions in the mechanicalroom are particularly a problem ifunducted return air is dumped into andcirculated through the mechanical room.

PRODUCTS OF COLLECTING DETAILED INFORMATION

an inventory of HVAC system components that need to berepaired, adjusted, or replaceda current record of control settings and operating schedulesa floor plan of the building showing airflow directions orpressure differentials around areas intended to run positive ornegative (e.g., special use areas)an inventory of pollutant sources and their locationsMaterial Safety Data Sheets for products used or stored withinthe buildinga record of usage for each zone or room, including the source ofoutside air and the presence of local exhaust (if any)

Collect Detailed Information

The collection of detailed information forthe IAQ profile can be handled as time isavailable. Areas that have been identifiedas presenting potential IAQ problemsshould be given the highest priority. Youmay want to review Section 2 for back-ground information on the factors thatcontribute to indoor air quality.

Inspect HVAC system condition andoperationUse your current maintenance records incombination with one or both of theHVAC Checklists to inspect HVAC

Developing an IAQ Profile 25 4 1

Occupants or staffsometimes open ceilingtiles into return plenumswhen attempting toeliminate odors. Buildingmanagers should be alert tosuch signs of occupantdissatisfaction in order toremedy the originalproblem and preventadditional problems, suchas the short-circuiting ofsupply air.

Sample Form

HVAC Checklist Short Form

Mechanical Room

Clean and dry?

(describe items in need of attention)

Stored refuse or chemicals?

Mechanical Equipment

Preventative maintenance (PM) plan in use?

Control System type

System operation

Sample Form

Pollutant Pathway Record For !AO Profiles

Building Area(zone, room)

Use Intended Pressure NeedsAttention?

(YIN)CommentsPositive

1+)

Negative(-)

777COMPLETEFORMSPAGES 191AND 175

26 Section 4

equipment and make sure that it is in goodoperating condition. A portion of theHVAC Checklist - Short Form is shownon this page, with the entire form repro-duced in Tab V. The HVAC Checklist -

Long Form (also reproduced in Tab V) isrecommended where a more detailedexamination is needed. You may want tocreate a new form incorporating elementsfrom your existing inspection forms.

Identify items of equipment that need tobe repaired, adjusted, or replaced. Recordcontrol settings and operating schedules forHVAC equipment for comparison tooccupancy schedules and current uses ofspace.

Inventory pollutant pathways

Using the sketch plan of the buildingthat was begun during the walkthroughinspection, indicate architecturalconnections (e.g., chases) and mechanicalconnections (e.g., ductwork, temperaturecontrol zones). Observe and record airflowbetween spaces intended to run positive ornegative and the areas that surround them(including airflow between perimeterrooms and outdoors). Note that hiddenpathways such as chases may travel bothvertically and horizontally and transportpollutants over long distances. Record theresults on the Pollutant Pathway Recordfor IAQ Profiles, the sketch plan, or both.The form is shown at the left (and in TabV), and a sample sketch plan is shown onthe opposite page.

Inventory pollutant sourcesUse the Pollutant and Source

Inventory (shown in part on page 28 andreproduced in full in Tab V) to recordpotential pollutant sources in the building.As you fill out the inventory form, note thelocations of major sources. Major sourcessuch as large items of equipment can berecorded on the floor plan. The ChemicalInventory Form (shown on page 28 andreproduced in Tab V) can be used to recordthe names and locations of chemicals orhazardous substances used or stored within

42

Vestibule

ReceptionArea

CA-WA:Witt

/ I PA-Aart?

EV- Ilevator Bank

Office

ConferenceRoom

Computer Room

1T1-

Lounge

-->Bathroom

CD

0MeZic

Room

A fire escape floorplan isvery useful for recordinginformation collectedduring IAQ profile develop-ment or while investigatingIAO complaints. The facilitymanager has begun toidentify the areas in whichair pressure relationshipsare (or should be) control-led and some ventilationand has noted source infor-mation. Symbols are e fornegative pressure, C) forpositive pressure, and 4for observed direction ofairflow. Utility chases,tunnels, and suspendedceilings could also bedrawn in to show pollutantpathways and drivingforces.

A

Ce5P. -(W`*-1 /141061n

SbtyStorage

1\

Office

2t4-tc cALkibd-

LdktAl2_ 2acit,


A-WeRS2 Cettl AfrAl-

A-AAO 14.62.-rW-Ltak_

Sample FormPollutant and Source Inventory

Using the list of potential source categories below, record anyindications of contamination or suspected pollutants that mayrequire further investigation or treatment.

Source Category Checked Needs Attention Location Comments

SOURCES OUTSIDE ME BUILDING

Contaminated Ambient Air

Pollen, dust

IndustrialcontaminantsGeneral vehicularcontaminants

Sample FormChemical Inventory Form

The inventory should include chemicals stored or used in thebuilding for cleaning, maintenance, operations, and pest control.If you have an MSDS (Material Safety Data Sheet) for the chemical,put a check mark in the right-hand column. If not, ask the chemicalsupplier to provide the MSDS, if one is available.

Date Chemical/Brand Name

Use StorageLocation(s)

MSDSon File?

SEECOMPLETEFORMSPAGES 213AND 221

28 Section 4

4 4

the building, such as those that may becontained in cleaning materials, biocides,paints, caulks, and adhesives. Ask yoursuppliers to provide you with MaterialSafety Data Sheets.

You may be unaware of the potentialhazards of some materials that arecommonly used in public and commercialbuildings. For example:

In 1990, EPA eliminated the sale ofmercury-containing interior latex paint.(Enamel paints do not contain mercury.)People are urged not to use exterior latexpaint indoors, as it may contain mercury.If you have paint in storage that mayhave been manufactured before August20, 1990, you may contact themanufacturer, the National PesticideTelecommunication Network ( I -800-858-7378), or your State HealthDepartment for guidance.In 1990, EPA banned the use ofhexavalent chromium chemicals incooling towers, because the chemicalshave been shown to be carcinogenic.Heating system steam should not be usedin the HVAC humidification system, asit may contain potentially harmfulchemicals such as corrosion inhibitors.

Collect information on buildingoccupancy

The Zone/Room Record shown on thefollowing page (and also reproduced inTab V) can be used during IAQ profiledevelopment to maintain an up-to-daterecord of the way each area of the buildingis used, its source of outdoor air, andwhether or not it is equipped with localexhaust. If underventilation is suspected,the form can be used to estimate ventila-tion rates in cubic feet per minute perperson or per square foot floor area, forcomparison to guidelines such as designdocuments, applicable building codes, orthe recommendations of ASHRAE 62-1989 (see the table that is reproduced inAppendix B).

Sample Form

Zone/Room RecordThis form is to be used differently depending on whether the goal is to prevent or diagnose IAQ problems.During development of a profile, this form should be used to record more general information about the entirebuilding; during an investigation, the form should be used to record more detailed information about thecomplaint area and areas surrounding the complaint area or connected to it by pathways.

PROFILE AND DIAGNOSIS INFORMATION DIAGNOSIS INFORMATION ONLY

Building Area(Zone/Room)

Use** Source ofOutdoor Air*

MechanicalExhaust?

(Write "No"or estimatecfm airflow)

Comments Peak Number ofOccupants or

Sq. Ft. Floor Area**

Total AirSupplied

(in cfm)***

Outdoor AirSupplied

per Person orper 150 Sq.Ft. Area****

Underventilation problems can occureven in areas where ventilation ratesapparently meet ASHRAE guidelines;proper distribution and mixing of supplyair with room air are also essential forgood ventilation.

If the information collected as youdevelop the IAQ profile indicates that youhave one or more IAQ problems, Sections6-8 provide guidance to help you deal withthem. If you need to prioritize these prob-lems, consider the apparent seriousness oftheir consequences. For example, combus-tion gas odors demand a more rapidresponse than thermostats that are out ofcalibration.

45

_



BEST COPY AVAILABLE

Managing Buildings for Good lAO

The relationships among building owners,management, staff, and occupants are animportant factor in decisions that affectindoor air quality. The objectives of themajor players in these relationships may bevery different. Occupants want thebuilding to be pleasant, safe, and attractive;if they are paying tenants, they also wantto get the maximum use out of the spacethey rent for the least cost. Buildingowners and management want to maintaina reputation for providing quality propertyat reasonable cost, but also need to derive aprofit. Facility staff are often caught in themiddle, trying to control operating andmaintenance costs while still keepingoccupants satisfied.

Regardless of the points on which theymay disagree, building occupants, staff,and management share the goal of provid-ing a healthy indoor environment. Recog-nition of this common goal may help avoidconflict when discussing IAQ-relatedpolicies.

Any IAQ management system will besuccessful only if it is organized to fit yourspecific building. It would not be appropri-ate for this document to prescribe anysingle approach. However, the skillsassociated with IAQ management activitieswill be identified to help building manage-ment decide who will be best able to carrythem out. Education and training programsfor staff and building occupants should beprovided to ensure that new procedures areunderstood and adopted.

Managing a building for good indoor airquality involves reviewing and amendingcurrent practice (and establishing newprocedures, if necessary) to:

Operate and maintain HVAC equipment

keep all equipment and controls in properworking order

keep interior of equipment and ductworkclean and dry

Oversee activities of staff, tenants, contrac-tors, and other building occupants thatimpact indoor air quality

smokinghousekeepingbuilding maintenanceshipping and receivingpest controlfood preparation and other special uses

Maintain communications with occupantsso that management will be informed ofcomplaints about the indoor environmentin a timely way

identify building management and staffwith IAQ responsibilitiesuse health and safety committees

Educate staff, occupants, and contractorsabout their responsibilities in relation toindoor air quality

staff traininglease arrangementscontracts

Identify aspects of planned projects thatcould affect indoor air quality andmanage projects so that good air qualityis maintained

redecorating, renovation, or remodelingrelocation of personnel or functionswithin the buildingnew construction

DEVELOPING AN IAOMANAGEMENT PLAN

The chart on page 32 shows the elementsof an IAQ management plan. Develop-ment of the management plan involvesreviewing and revising staff responsibili-ties so that IAQ considerations becomeincorporated into routine procedures.

Managing Buildings for Good IAQ 31

4 6

!AO managementsystems will only besuccessful if they areorganized to fit yourspecific building.

Organizations may assign responsibility foroperations, recordkeeping, purchasing,communications, planning, and policy-making in many different ways. However,the key elements of good IAQ managementremain the same:

Reach an understanding of the funda-mental influences that affect indoor airquality in your building by:

becoming familiar with literature on IAQkeeping abreast of new information

Select an IAQ manager with:

clearly defined responsibilitiesadequate authority and resources

FIGURE 5-1: Developing an IAD Management Plan

Select an IAQ Manager

Review IAQ Profileand Existing Records

Assign StaffResponsibilities/Train Staff

Facilities Operationand Maintenance

Housekeeping

Pest Control

Tenant Relations

RenovationRedecoratingRemodeling

Smoking

32 Section 5

47

Use the IAQ profile and other availableinformation to:

evaluate the design, operation, and usageof the buildingidentify potential IAQ problem locationsidentify staff and contractors whoseactivities affect indoor air quality

Review and revise staff responsibilities toensure that responsibilities that may affectindoor air quality are clearly assigned. Inaddition, establish lines of communicationfor sharing information pertaining to:

equipment in need of repair orreplacementplans to remodel, renovate, or redecoratenew uses of building space or increases inoccupant populationinstallation of new equipment

Review standard procedures and makenecessary revisions to promote goodindoor air quality, such as:

terms of contracts (e.g., pest control,leases)

scheduling of activities that produce dust,emissions, odorsscheduling of equipment operation,inspection, and maintenancespecifications for supplies (e.g., cleaningproducts, construction materials, furnish-ings)

policy regarding tobacco smoking withinthe building

Review the existing recordkeeping systemand make necessary revisions to:

establish a system for logging IAQ-related complaintsobtain Material Safety Data Sheets forhazardous materials used and stored in thebuilding

Educate building staff, occupants, andcontractors about their influence onindoor air quality by:

establishing a health and safety committeeinstituting training programs as needed

IAQ problems may occur even in

buildings whose owners and managersconscientiously apply the best available

information to avoid such problems.Those who can demonstrate their ongoingefforts to provide a safe indoor environ-ment are in a strong legal and ethical

position if problems do arise.

Select an IACI ManagerIAQ management will be facilitated if oneindividual is given overall responsibilityfor IAQ. Whether or not this person isgiven the title of "IAQ Manager," he orshe should have a good understanding ofthe building's structure and function andshould be able to communicate withtenants, facility personnel. and buildingowners or their representatives about IAQ

issues.

The IAQ manager's ongoing responsi-bilities might include:

developing the IAQ profileoverseeing the adoption of new

procedures

establishing a system for communicatingwith occupants about IAQ issuescoordinating staff efforts that affectindoor air quality, and making sure thatstaff have the information (e.g., operat-ing manuals, training) and authority tocarry out their responsibilitiesreviewing all major projects in thebuilding for their IAQ implicationsreviewing contracts and negotiating withcontractors (e.g., cleaning services, pestcontrol contractors) whose routineactivities in the building could create

IAQ problemsperiodically inspecting the building forindicators of IAQ problemsmanaging IAQ-related recordsresponding to complaints or observations

regarding potential IAQ problemsconducting an initial walkthroughinvestigation of any IAQ complaints

PRODUCTS OF THE REVIEW OF THE IAD PROFILEAND OTHER EXISTING RECORDS

a priority list of locations and activities within the building thatwill require special attention in order to prevent indoor air qualityproblems

a list of staff and contractors whose responsibilities need to beincluded in the IAQ management plan

Review IACI Profile and OtherExisting Records

If the IAQ manager was not activelyinvolved in developing the IAQ profile,one of the first tasks will be to review theprofile carefully. The manager can start byalso identifying building locations with apotential for IAQ problems, staff andcontractors whose activities impact indoorair quality, and other building occupantswhose activities impact indoor air quality.

In addition to information from the IAQprofile, it may be helpful to review leaseforms and other contractual agreements foran understanding of the respective legal

responsibilities of the building manage-ment, tenants, and contractors. Incorpora-

tion of IAQ concerns into legal documentshelps to ensure the use of proper materials

and procedures by contractors and can help

to limit the load placed on ventilationequipment by occupant activities.

Assign Responsibilities/Train Staff

The assignment of responsibilities varies

widely between organizations, depending

upon the routine activities to be carried out

and the capabilities of the availablepersonnel. It would not be appropriate forthis document to suggest how IAQ-relatedresponsibilities should be allocated in your

organization. For example, issues of

access in buildings with tenant-occupied

space highlight the need for cooperation

between building managers and the

4 8Managing Buildings for Good IAQ 33

IAG management willbe facilitated if oneindividual is givenoverall responsibilityfor !AO.

A clean mechanical room,free of tracked-in dirt andstored chemicals, is animportant element in theprevention of indoor airquality problems. Airbornecontaminants in themechanical room can bedrawn into ductworkthrough return air openingsor unsealed seams in returnducts and circulatedthroughout the building.

tenants' office managers. The buildingstaff may be limited in its access to tenantspaces and tenants may not have access tobuilding operations areas such as mechani-cal rooms, yet both tenants and buildingmanagement have responsibilities formaintaining good indoor air quality.

Facility personnel are not generallytrained to think about IAQ issues as theygo about their work. Even though buildingstaff may be observing events and condi-tions that would indicate potential prob-lems to an experienced IAQ investigator,the staff member's attention may bedirected elsewhere. As new practices areintroduced to prevent indoor air qualityproblems, an organized system ofrecordkeeping will help those practices tobecome part of routine operations and to"flag" decisions that could affect IAQ(e.g., renovations, new tenants). The bestresults can be achieved by taking time tothink about the established channels ofcommunication within your organization,so that new forms can be integrated intodecisionmaking with minimum disruptionof normal procedures.

r

:rtrt,

90.4ta _

34 Section 5 4 9

Using information from the IAQprofile, the IAQ manager should workwith staff and contractors to ensure thatbuilding operations and planning processesincorporate a concern for indoor airquality. New procedures, recordkeepingrequirements, or staff training programsmay be needed. (Growing interest in IAQis stimulating government agencies andprivate sector organizations to developtraining programs. See Appendix G foradditional information.) The flow ofinformation between the IAQ manager andstaff, occupants, and contractors isparticularly important. Good indoor airquality requires prompt attention tochanging conditions that could cause IAQproblems, such as installation of newequipment or furnishings, increases inoccupant population, or new uses ofLOOMS.

Facility Operation and Maintenance

Indoor air quality can be affected bothby the quality of maintenance and by thematerials and procedures used in operatingand maintaining the building componentsincluding the HVAC system.

Facility staff who are familiar withbuilding systems in general and with thefeatures of their building in particular arean important resource in preventing andresolving indoor air quality problems.Facility personnel can best respond toindoor air quality concerns if they under-stand how their activities affect indoor airquality. It may be necessary to changeexisting practices or introduce newprocedures in relation to:

Equipment operating schedules: Confirmthat the timing of occupied and unoccu-pied cycles is compatible with actualoccupied periods, and that the building isflushed by the ventilation system beforeoccupants arrive. ASHRAE 62-1989provides guidance on lead and lag timesfor HVAC equipment. In hot, humid

climates, ventilation may be needed duringlong unoccupied periods to prevent moldgrowth.

Control of odors and contaminants:Maintain appropriate pressure relationshipsbetween building usage areas. Avoidrecirculating air from areas that are strongsources of contaminants (e.g., smokinglounges, chemical storage areas, beautysalons). Provide adequate local exhaustfor activities that produce odors, dust, orcontaminants, or confine those activities tolocations that are maintained undernegative pressure (relative to adjacentareas). For example, loading docks are afrequent source of combustion odors.Maintain the rooms surrounding loadingdocks under positive pressure to preventvehicle exhaust from being drawn into thebuilding. Make sure that paints, solvents,and other chemicals are stored and handledproperly. with adequate (direct exhaust)ventilation provided. If local filter trapsand adsorbents are used, they requireregular maintenance. Have vendorsprovide Material Safety Data Sheets(MSDSs).

Ventilation quantities: Compare outdoorair quantities to the building design goaland local and State building codes andmake adjustments as necessary. It is alsoinformative to see how your ventilationrate compares to ASHRAE 62-1989,because that guideline was developed withthe goal of preventing 1AQ problems.(Note: Increasing ventilation quantities tomeet ASHRAE guidelines may exceed thecapacity of HVAC equipment to conditionthe air.)

HVAC equipment maintenance sched-ules: Inspect all equipment regularly (perrecommended maintenance schedule) toensure that it is in good condition and isoperating as designed (i.e., as close to thedesign setpoints for controls as possible).Most equipment manufacturers providerecommended maintenance schedules for

their products. Components that areexposed to water (e.g., drainage pans,coils, cooling towers, and humidifiers)require scrupulous maintenance to preventmicrobiological growth and the entry ofundesired microbiologicals or chemicalsinto the indoor airstream.

HVAC inspections: Modify the HVACChecklists (reproduced in Tab V) asnecessary so that they are appropriate forinspection of the specific equipment inyour building. Be thorough in conductingthese inspections. Items such as smallexhaust fans may operate independentlyfrom the rest of the HVAC system and areoften ignored during inspections. Asequipment is added, removed, or replaced,document any changes in function,capacity, or operating schedule for futurereference. It may also be helpful to storeequipment manuals and records of equip-ment operation and maintenance in thesame location as records of occupantcomplaints for easy comparison if 1AQproblems arise.

Building maintenance schedules: Tryto schedule maintenance activities thatinterfere with HVAC operation or produceodors and emissions (e.g., painting, roofingoperations) so that they occur when thebuilding is unoccupied. Inform occupantswhen such activities are scheduled and, ifpossible, use local ventilation to ensurethat dust and odors are confined to thework area.

Purchasing: Review the general informa-tion provided by MSDS and requestinformation from suppliers about thechemical emissions of materials beingconsidered for purchase.

Note: At present there is no generalsystem for certifying or labeling low-emission products nor is there a standardprocedure for building managers to use ingathering emissions data on products theyare considering for purchase. Limitedinformation on some materials such as

5 0


Be thorough inconducting HVACinspections. Itemssuch as small exhaustfans may operateindependently fromthe rest of the systemand are often ignoredduring inspections.

PREVENTIVE MAINTENANCEAn HVAC system requires adequate preventive maintenance (PM)and prompt attention to repairs in order to operate correctly andprovide suitable comfort conditions and good indoor air quality.The HVAC system operator(s) must have an adequate understand-ing of the overall system design, its intended function, and itslimitations. The preventive maintenance program must be prop-erly budgeted and implemented, not merely planned on paper.

A well-implemented PM plan will improve the functioning of themechanical systems and usually save money when evaluated on alife-cycle basis. However, in some buildings, because of budgetaryconstraints, maintenance is put off until breakdowns occur orcomplaints arise, following the "if it isn't broken, don't fix it"philosophy. This type of program represents a false economy andoften increases the eventual cost of repairs.

Poor filter maintenance is a common example of this phenom-enon. Filters that are not changed regularly can become a bed forfungal growth, sometimes allowing particles or microorganisms tobe distributed within the building. When filters become clogged,the fans use more energy to operate and move less air. If the filtersare an inexpensive, low-efficiency type that becomes clogged andthen "blows out," the coils then accumulate dirt, causing anotherincrease in energy consumption. Poor air filter efficiency and poormaintenance may cause dirt to build up in ducts and becomecontaminated with molds, possibly requiring an expensive ductcleaning operation.

General elements of a PM plan include:periodic inspection, cleaning, and service as warrantedadjustment and calibration of control system componentsmaintenance equipment and replacement parts that are of goodquality and properly selected for the intended function

Critical HVAC system components that require PM in order tomaintain comfort and deliver adequate ventilation air include:

outdoor air intake openingdamper controlsair filtersdrip panscooling and heating coilsfan beltshumidification equipment and controlsdistribution systemsexhaust fansSome private sector organizations have developed guidance on

preventive maintenance. (See discussion in Guidelines of CareDeveloped by Trade Associations on page 43.)

36 Section 5

pressed-wood products is available, andmore may be expected in the future.Public and private sector organizations areworking to develop product testingprocedures for acceptance by such organi-zations as the American Society forTesting and Materials (ASTM).

Preventive maintenance management:Maintenance "indicators" are available tohelp facility staff determine when routinemaintenance is required. For example, airfilters are often neglected (sometimes dueto reasons such as difficult access) and failto receive maintenance at proper intervals.Installation of an inexpensive manometer,an instrument used to monitor the pressureloss across a filter bank, can give animmediate indication of filter conditionwithout having to open the unit to visuallyobserve the actual filter.

Computerized systems are available thatcan prompt your staff to carry out mainte-nance activities at the proper intervals.Some of these programs can be connectedto building equipment so that a signal istransmitted to your staff if a piece ofequipment malfunctions. Individual areascan be monitored for temperature, airmovement, humidity, and carbon dioxide,and new sensors are constantly entering themarket. These sensors can be programmedto record data and to control multipleelements of the HVAC system.

Housekeeping

Indoor air quality complaints can arisefrom inadequate housekeeping that fails toremove dust and other dirt. On the otherhand, cleaning materials themselvesproduce odors and emit a variety ofchemicals.

As they work throughout your building,cleaning staff or contractors may be thefirst to recognize and respond to potentialIAQ problems. Educate them about topicssuch as the following:

5 1

Cleaning schedules: Consider howcleaning activities are scheduled. Manag-ers may want to schedule the use of somecleaning agents that introduce strong odorsor contaminants during unoccupiedperiods. However, make sure that fumesfrom cleaning products are eliminatedbefore air handling systems switch to their"unoccupied" cycles.

Purchasing: Become more familiar withthe chemicals in cleaning and maintenanceproducts and their potential toxicity.Select the safest available materials thatcan achieve your purpose. Review theinformation provided by product labelsand Material Safety Data Sheets. Requestinformation from suppliers about thechemical emissions of products beingconsidered for purchase.

Materials handling and storage: Reviewthe use of cleaning materials to ensureproper use and storage.

Trash disposal: Follow proper trashdisposal procedures. If there is a restau-rant in the building, require daily pick-upof perishable refuse. Ensure that thecontainers are covered, pest control iseffective, and that the trash collection areais cleaned at least daily.

Shipping and Receiving

Shipping and receiving areas can createindoor air quality problems regardless ofthe types of materials being handled.Vehicle exhaust fumes can be minimizedby prohibiting idling at the loading dock.This is particularly important if the loadingdock is located upwind of outdoor airintake vents. You can also reduce draftsand pollutant entry by pressurizing interiorspaces (e.g., corridors) and by keepingdoors closed when they are not in use.

A good preventive maintenanceprogram can help a facility manageridentify and correct problems beforethey occur. If this fan belt breaks, thearea served by the air handling unit maybe without ventilation. If it is slipping, itis already reducing the airflow.

A termiticide misapplication resulted inan indoor air quality problem in thisschool. Detectable levels of chlordanewere found in both wipe (surface) andair samples near the injection holesdrilled into the ground floor. Note thesmall white circles near the wall. (Underan agreement with EPA, manufacturershave withdrawn chlordane from sale.)Proper application methods areimportant for all pesticides.


.4,

INTEGRATED PEST MANAGEMENT

Integrated Pest Management (IPM) is a coordinated approach topest control intended to prevent unacceptable levels of pests, whilecausing the least possible hazard to people, property, and theenvironment and using the most cost-effective means. IPM uses acombination of tactics, including sanitation, monitoring, habitatmodification, and the judicious application of pesticides whenabsolutely necessary.

IPM methods include:

improved sanitation (e.g., removing food from desks, cleaning)inspection and monitoring of pest population sitesmanaging waste (e.g., keeping refuse in tight containers, locatingwaste containers away from building if possible)maintaining structures (e.g., fixing leaking pipes promptly,sealing cracks)adding physical barriers to pest entry and movement (e.g.,screens for chimneys, doors, and windows; air curtains)modifying habitats (e.g., removing clutter, relocating outside lightfixtures away from doors)using traps (e.g., light traps, snap traps, and glue boards)using pesticides judiciously

An efficient IPM program will integrate pest managementplanning with preventive maintenance, housekeeping practices,landscaping, occupant education, and staff training.

Pest Control

Pest control activities that depend uponthe use of pesticides involve the storage,handling, and application of materials thatcan have serious health effects. Commonconstruction, maintenance practices, andoccupant activities provide pests with air,moisture, food, warmth, and shelter.Caulking or plastering cracks, crevices, orholes to prevent harborage behind wallscan often be more effective than pesticideapplication at reducing pest populations toa practical minimum.

Integrated Pest Management (IPM) is alow-cost approach to pest control basedupon knowledge of the biology andbehavior of pests. Adoption of an IPMprogram can significantly reduce the needfor pesticides by eliminating conditionsthat provide attractive habitats for pests.

38 Section 5

If an outside contractor is used for pestcontrol, it is advisable to review the termsof the contract and include IPM principleswhere possible. The following itemsdeserve particular attention.

Pest control schedule: Schedule pesticideapplications for unoccupied periods, ifpossible, so that the affected area can beflushed with ventilation air before occu-pants return. Pesticides should only beapplied in targeted locations, with mini-mum treatment of exposed surfaces. Theyshould be used in strict conformance withmanufacturers' instructions and EPAlabels. General periodic spraying may notbe necessary. If occupants are to bepresent, they should be notified prior to thepesticide application. Particularly suscep-tible individuals could develop seriousillness even though they are only mini-mally exposed.

Materials selection, handling, andstorage: Select pesticides that are species-specific and attempt to minimize toxicityfor humans and non-target species. Askcontractors or vendors to provide EPAlabels and MSDSs. Make sure thatpesticides are stored and handled properlyconsistent with their EPA labels.

Ventilation of areas where pesticides areapplied: If only limited areas of thebuilding are being treated, adjust theHVAC system so that it does not distributecontaminated air throughout the rest of thebuilding. Consider using temporaryexhaust systems to remove contaminantsduring the work. It may be necessary tomodify HVAC system operation duringand after pest control activities (e.g.,running air handling units on 100%outdoor air for some period of time orrunning the system for several complete airexchanges before occupants re-enter thetreated space).

5 3

MATERIAL SAFETYDATA SHEETS

Under OSHA regulations, responsible parties are required to document information onpotentially hazardous products. These Material Safety Data Sheets (MSDSs) may beof limited help in identifying some products that may pose IAQ concerns. However,professional judgment and collection of additional information may be necessary inorder to make full use of the MSDS. The following table summarizes some of theissues to keep in mind when deciding whether information from MSDSs is applicableto emission sources and exposures of concern in a building.

Item

Substances Covered

Possible Uses

MSDSs may identify significantairborne contaminants

Comments

MSDSs may not be available onsite formany products

some components are listed asproprietary and are not disclosed

MSDSs do not always highlight productsmost likely to be airborne

contaminant byproducts inadvertentlyformed during manufacture won't alwaysbe listed

Personal Protection/ may suggest precautions forFirst Aid conducting source inspection

usually relates only to high-level, worst-case exposures in general industry

Health Effects generally presents types of healtheffects that may be expected primar-ily at high levet (e.g., industrial)exposures

symptoms listed may not occur at low-level concentrations found in indoor air

MSDSs may not include more subtle IAQaspects such as nuisance factors andsensitivity to mixtures

Physical Data odor description may help identifysources

volatility may suggest which prod-ucts are likely to be airborne

contaminants to expect in event of afire or decomposition may be listed

reactivity data may suggest potentialproblems with storage or use

reference material on how to use physicaldata information to predict IAQ impactsmay be scarce

Control Measures identifies proper storage andpackaging procedures

many office chemicals are kept in muchsmaller amounts than found in industrialsettings

identifies steps for cleanup of grossspills spill cleanup may not eliminate airborne

contamination

does not specify routine emission controls

A reasonable effort should be made to collect available MSDSs during IAQ profiledevelopment. Care should be taken to consider information that is relevant to IAQconcerns. Other important indicators of how a particular product may affect IAQ areavailable from direct odor and dust observations, a review of work practices, andinterviews with operators and occupants. The manufacturer is a good source of follow-up information on a given product (phone number should be included on each MSDS).

Managing Buildings for C5o4IAQ 39 5 Li

It is important for buildingoccupants to understandthat their activities cancreate indoor air qualityproblems. Smokingreleases both carcinogenicand irritating substancesinto the air.

Occupant Relations

Managing occupant relations to preventIAQ problems involves: allocating spaceand monitoring the use of building areas toisolate odor- and contaminant-producingactivities and avoid re-entrainment; estab-lishing a communication strategy that isresponsive to complaints and providestenants with information about their role inpreventing indoor air quality problems;and modifying employee manuals or leaseagreements as necessary to clarify theresponsibilities of occupants and buildingmanagement. A health and safety commit-tee or joint tenant-management IAQ taskforce that represents all of the major inter-est groups in the building can be veryhelpful in disseminating information andfostering a cocrperative approach to IAQmanagement. See Section 3 for a discus-sion of these points.

Renovation, Redecorating, andRemodeling

Renovation, redecorating, and re-modeling activities can create indoor airproblems by producing dust, odors, micro-biologicals and their spores, and emissions.It is difficult to prevent IAQ problems ifsome building areas are undergoing reno-vation while adjoining areas continuenormal operations.

40 Section 5

Close monitoring of renovation,redecorating, and remodeling projects isrecommended. The following suggestionsmay be helpful:

Working with professional consultants:Communicate your concern about prevent-ing indoor air quality problems to theengineer, architect, interior designer, orother professionals involved in the project.

Product selection: Specify products andprocesses that minimize odors and emis-sions, while maintaining adequate safetyand efficacy. Review the general informa-tion provided by the product labels andMSDSs. Request information fromsuppliers about the chemical emissions ofproducts being considered for purchase.

Work schedules: Schedule activities thatproduce dust, odors, or emissions forunoccupied periods if possible.

Isolation of work areas: Block off returnregisters so that contaminants are notrecirculated from the demolition/construc-tion area into adjoining areas, and installtemporary barriers to confine dust andnoise. If possible, install temporary localexhaust to remove odors and contaminants,and check to confirm that the temporaryventilation system is operating as planned.

Installation of new furnishings: Asksuppliers to store new furnishings in aclean, dry, ventilated location so thatvolatile organic compounds will be emittedbefore installation. Minimize the use ofadhesives during installation or specifylow-emitting products. After new furnish-ings are installed, increase the ventilationrate to flush the area with outdoor air anddilute emissions.

5 5

Smoking

Although there are many potentialsources of indoor air pollution, bothresearch and field studies have shown thatenvironmental tobacco smoke (ETS) is oneof the most widespread and harmful indoorair pollutants. Environmental tobaccosmoke is a combination of sidestream

smoke from the burning end of thecigarette, pipe, or cigar and the exhaledmainstream smoke from the smoker. ETScontains over 4,000 chemicals; 43 of thesechemicals are known animal or humancarcinogens. Many other chemicals inETS are tumor promoters, tumor initiators,co-carcinogens (i.e., chemicals that areable to cause cancer when combined withanother substance), or cancer precursors(i.e., compounds that can make it easier toform other carcinogenic chemicals).

In 1986, The Health Consequences ofInvoluntary Smoking: A Report of theSurgeon General on EnvironmentalTobacco Smoke concluded that ETS was acause of lung cancer in healthy non-smokers and that "the scientific caseagainst involuntary smoking as a publichealth risk is more than sufficient to justifyappropriate remedial action, and the goalof any remedial action must be to protectthe non-smoker from environmentaltobacco smoke." In the same year, theNational Research Council of the NationalAcademy of Sciences issued a report,Environmental Tobacco Smoke: Measur-ing Exposures and Assessing HealthEffects, which also concluded that passivesmoking increases the risk of lung cancerin adults.

In June 1991, NIOSH issued a CurrentIntelligence Bulletin (#54) on ETS in theworkplace that dealt with lung cancer andother health effects. In its Bulletin,NIOSH stated that the weight of evidenceis sufficient to conclude that ETS cancause lung cancer in non-smokers (i.e.,those who inhale ETS). It recommendedthat the preferable method to protect non-smokers is the elimination of smokingindoors and that the alternative method isto require that smoking be permitted onlyin separately ventilated smoking areas.The NIOSH Bulletin emphasized thatprovision of such isolated areas should beviewed as an interim measure until ETScan be completely eliminated indoors.

PRODUCTS OF THE ASSIGNMENT OFRESPONSIBILITIES AND REVIEW OF TRAINING

job descriptions and/or contracts, work procedures, andschedules revised to reflect indoor air quality concernsprocedures for reviewing purchases of supplies, new projects,contracts, and policies in relation to indoor air qualitysmoking policy revisions, if necessaryplans for educating occupants and training staff training inrelation to indoor air quality

Smoking areas must be separatelyventilated, negatively pressurized inrelation to surrounding interior spaces. andsupplied with much more ventilation thannon-smoking areas. The NIOSH Bulletinalso recommends that the air from thesmoking area should be exhausted directlyoutdoors and not recirculated within thebuilding or vented with the general exhaustfor the building. ASHRAE Standard 62-1989 recommends that smoking areas besupplied with 60 cubic feet per minute (60cfm) per occupant of outdoor air; thestandard also recognized that using transferair, which is pulled in from other parts ofthe building, to meet the standard iscommon practice.

Both EPA and NIOSH advise thatbuilding owners or facility managersconsidering the introduction of smokingrestrictions should implement smokingcessation programs. In addition, employ-ees and labor unions should be involved inthe development of non-smoking policiesin the workplace.

(Refer to Appendix G for citations onpublications mentioned in this section.especially NIOSH Current IntelligenceBulletin (#54): Environmental TobaccoSmoke in the Workplace Lung Cancerand Other Health Effects. Additionalresources on ETS, including an assessmentof respiratory disorders in children andlung cancer risks in adults, and a guide todeveloping effective smoking policies, willbe available from EPA early in 1992.)

56Managing Buildings for Good IAQ 41

According to a 1986report of the SurgeonGeneral, "the caseagainst involuntarysmoking is more thansufficient to justifyappropriate remedialaction to protect thenon-smoker fromenvironmental tobaccosmoke."

Sample FormManagement Checklist

Date Begun Locationor Completed Responsible Person (NA" if the item is not

Item (as applicable) (name, telephone) applicable to this building)

IAO PROFILE

Collect and ReviewExisting Records

HVAC design data, operatinginstructions, and manuals

HVAC maintenance and calibrationrecords, testing and balancing reports

Inventory of locations whereoccupancy, equiptment, or buildinguse has changed


Conduct a WalkthroughInspection of the Building

List of responsible staff and/orcontractors, evidence of training,and job descriptions

Identification of areas where positiveor negative pressure should bemaintained


The MO Management Checklistshown in part here and included in fullwithin Tab V can be used to helpconfirm that you have accounted for themajor factors that could cause IAQproblems in your building.

42 Section 5

5 7

GUIDELINES OFCARE DEVELOPEDBY TRADEASSOCIATIONS

The following associations have developed guidelines of care that may have adirect or indirect impact on indoor air quality. These standards are describedbelow so that building management may become aware of them. Neither EPAnor NIOSH endorse these standards.

Air ConditioningContractors ofAmerica(ACCA)

Technical Reference Bulletin Series. Indoor air quality is one of the topics coveredin this series of technical bulletins on heating, ventilation, and air conditioning(HVAC). Bulletins can be filed in the ACCA Technical Reference Notebook. The AirSide Design tab of the notebook includes bulletins devoted to indoor air qualitycontrol.

Air-Conditioning andRefrigeration Institute(ARI)

Air Conditioning and Refrigeration Equipment General Maintenance Guidelines forImproving the Indoor Environment (1991). General maintenance requirements forheating ventilation, air conditioning, and refrigeration (HVACR) equipment.Specific equipment/component maintenance is given for the following: air cleaningsystems; ducts; registers/diffusers and air terminals; dampers/economizers; drainpans; air handlers; humidifiers; package terminal units; and evaporator, condenser,hydronic and economizer coils. The guidelines do not supersede any maintenanceinstructions that are provided by the manufacturer. In addition, the Institute hasissued an Indoor Air Quality Briefing Paper that addresses the interactionsbetween HVACR equipment and the quality of indoor air.

Associated AirBalance Council(AABC)

National Standards for Testing and Balancing Heating,Ventilation, and Air Condi-tioning Systems (1989). Establishes a minimum set of field testing and balancingstandards and provides comprehensive and current data on testing and balancingHVAC systems. Chapters receiving special attention include Cooling TowerPerformance Tests, Sound Measurements, Vibration Measurements, Fume Hoods,and AABC General Specifications. The book contains a complete index to thetechnical data provided.

NationalEnvironmentalBalancing Bureau(NEBB)

Procedural Standards for Testing, Adjusting, and Balancing of EnvironmentalSystems (1991). A "how-to" set of procedural standards that provide systematicmethods for testing, adjusting, and balancing (TAB) of HVAC systems. Includessections on TAB instruments and calibration, report forms, sample specifications,and engineering tables and charts. A valuable innovation is the "Systems Readyto Balance" start-up checklist to help organize jobs systematically. Other featuresinclude: additional erigineering data; condensed duct design tables/charts; hy-dronic design tables/charts; and pertinent HVAC equations in U.S. and metric units.

National Pest ControlAssociation(NPCA)

Good Practice Statements. Periodically updated, officially approved and adoptedby the Association's Board of Directors, these "Good Practice Statements" aredesigned as guidelines for performing various services rather than standards ofoperation. In addition, the Association produces a self-study series for techniciansthat covers five areas of pest control, management manuals, an encyclopedia ofstructural pest control, a number of specific subject matter technical referencemanuals, and a pamphlet series.

Sheet Metal andAir ConditioningContractors' NationalAssociation(SMACNA)

HVAC Duct Construction Standards Metal and Flexible (1985). Primarily forcommercial and institutional work, this set of construction standards is a collectionof material from earlier editions of SMACNA's low-pressure, high-pressure, flexibleduct, and duct liner standards. In addition, SMACNA has published a manualentitled Indoor Air Quality that contains basic information on many aspects ofindoor air quality and guidance on conducting building evaluations and indoor airquality audits. Other related SMACNA publications include HVAC Duct SystemsInspection Guide, HVAC SystemsTesting, Adjusting and Balancing, and HVACAir Duct Leakage Test Manual.

Cr,

Managing Buildings for Good IAQ.43 58

RESOLVING IAO PROBLEMS

Building Air Quality411

11111111

5 9 Printed on Recycled Paper

Diagnosing IAO Problems

The goal of the diagnostic buildinginvestigation is to identify and solve theindoor air quality complaint in a way thatprevents it from recurring and that does notcreate other problems. This sectiondescribes a method for discovering thecause of the complaint and presents a"toolbox" of diagnostic activities to assistyou in collecting information.

Just as a carpenter uses only the toolsthat are needed for any given job, an IAQinvestigator should use only the investiga-tive techniques that are needed. Manyindoor air quality complaints can beresolved without using all of the diagnostictools described in this chapter. Forexample, it may be easy to identify thesource of cooking odors that are annoyingnearby office workers and solve theproblem by controlling pressure relation-ships (e.g., installing exhaust fans) in thefood preparation area. Similarly, mostmechanical or carpentry problems prob-ably require only a few of the many toolsyou have available and are easily accom-plished with in-house expertise.

The use of in-house personnel buildsskills that will be helpful in minimizingand resolving future problems. On theother hand, some jobs may be best handledby contractors who have specializedknowledge and experience. In the sameway, diagnosing some indoor air qualityproblems may require equipment and skillsthat are complex and unfamiliar. Yourknowledge of your organization andbuilding operations will help in selectingthe right tools and deciding whether in-house pasonnel or outside professionalsshould be used in responding to thespecific IAQ problem.

Start (reason for concern)

Initial walkthroughpreparationvisual inspectiontalk with occupants and staff

4Do you have

an explanationfor the complaint ?

No

Yes

Collect additionalinformation about

building occupantsthe HVAC systempollutant pathwayspollutant sources(sample contaminants if needed)

4Develop one or more hypothesesto explain the problem. Test bymanipulating building conditionsor exposure, or by performingappropriate tests.

Do resultssupport yourhypothesis ?

Yes Attempta controlstrategy

Follow-upvalidation

Is theproblemsolved ?

FIGURE 6-1:Conducting an !AG InvestigationNote: Outside assistance may be needed atany point in the investigation, dependingupon the complexity of the problem, the skillsavailable in-house, time pressures, or otherfactors.

6 0Diagnosing IAQ Problems 45

Yes

Make necessarychanges so thatthe problem willnot recur.

Finish

The IAD investigationis often a repetitivecycle of information-gathering, hypothesisformation, andhypothesis testing.

OVERVIEW: CONDUCTING ANIAO INVESTIGATION

An IAQ investigation begins with one ormore reasons for concern, such as occu-pant complaints. Some complaints can beresolved very simply (e.g., by asking a fewcommon sense questions of occupants andfacility staff during the walkthrough). Atthe other extreme, some problems couldrequire detailed testing by an experiencedIAQ professional. In this section "theinvestigator" refers to in-house staffresponsible for conducting the IAQinvestigation.

The flowchart on page 45 shows thatthe IAQ investigation is a cycle of infor-mation-gathering, hypothesis formation,and hypothesis testing. The goal of theinvestigation is to understand the IAQproblem well enough so that you can solveit. Many IAQ problems have more thanone cause and may respond to (or require)several corrective actions.

Initial Walkthrough

An initial walkthrough of the problem area'provides information about all four of thebasic factors influencing indoor air quality(occupants, HVAC system, pollutantpathways, and contaminant sources). Theinitial walkthrough may provide enoughinformation to resolve the problem. At theleast, it will direct further investigation.For example, if the complaint concerns anodor from an easily identified source (e.g.,cooking odors from a kitchen), you maywant to study pollutant pathways as a nextstep, rather than interviewing occupantsabout their patterns of discomfort.

Developing and TestingHypotheses

As you develop an understanding of howthe building functions, where pollutantsources are located, and how pollutantsmove within the building, you may thinkof many "hypotheses," potential explana-

46 Section 661

tions of the IAQ complaint. Buildingoccupants and operating staff are often agood source of ideas about the causes ofthe problem. For example, they candescribe changes in the building that mayhave occurred shortly before the IAQproblem was noticed (e.g., relocatedpartitions, new furniture or equipment).

Hypothesis development is a processof identifying and narrowing downpossibilities by comparing them with yourobservations. Whenever a hypothesissuggests itself, it is reasonable to pauseand consider it. Is the hypothesisconsistent with the facts collected so far?

You may be able to test your hypothesisby modifying the HVAC system orattempting to control the potential sourceor pollutant pathway to see whether youcan relieve the symptoms or other condi-tions in the building. If your hypothesissuccessfully predicts the results of yourmanipulations, then you may be ready totake corrective action. Sometimes it isdifficult or impossible to manipulate thefactors you think are causing the IAQproblem; in that case, you may be able totest the hypothesis by trying to predict howbuilding conditions will change over time(e.g., in response to extreme outdoortemperatures).

Collecting AdditionalInformation

If your hypothesis does not seem to be agood predictor of what is happening in thebuilding, you probably need to collectmore information about the occupants,HVAC system, pollutant pathways, orcontaminant sources. Under somecircumstances, detailed or sophisticatedmeasurements of pollutant concentrationsor ventilation quantities may be required.Outside assistance may be needed ifrepeated efforts fail to produce a successfulhypothesis or if the information requiredcalls for instruments and procedures thatare not available in-house.

Results of the Investigation

Analysis of the information collectedduring your IAQ investigation couidproduce any of the following results:

The apparent cause(s) of the complaint(s)is (are) identified.

Remedial action and follow-up evaluationwill confirm whether the hypothesis iscorrect.

Other IAQ problems are identified thatare not related to the original complaints.

These problems (e.g., HVAC malfunc-tions, strong pollutant sources) should becorrected when appropriate.

A better understanding of potential IAQproblems is needed in order to develop aplan for corrective action.

It may be necessary to collect moredetailed information and/or to expand thescope of the investigation to includebuilding areas that were previouslyoverlooked. Outside assistance may beneeded.

The cause of the original complaintcannot be identified.

A thorough investigation has found nodeficiencies in HVAC design or operationor in the control of pollutant sources, andthere have been no further complaints. Inthe absence of new complaints, the originalcomplaint may have been due to a single,unrepeated event or to causes not directlyrelated to IAQ.

Using Outside Assistance

Some indoor air quality problems may bedifficult or impossible for in-houseinvestigators to resolve. Special skills orinstruments may be needed. Other factorscan also be important, such as the benefitof having an impartial outside opinion orthe need to reduce potential liability from a

\

serious IAQ problem. You are best able tomake the judgment of when to bring in anoutside consultant. See Section 8 for adiscussion of hiring professional assistanceto solve an IAQ problem.

INITIAL INALKTHROUGH

An investigation may require one or manyvisits to the complaint area. The amountof preparatory work needed before theinitial walkthrough varies with the natureand scope of the complaint and theexpertise of the investigator, among otherfactors. For example, an in-house investi-gator who is already familiar with thelayout and mechanical system in thebuilding may begin responding to acomplaint about discomfort by goingdirectly to the complaint area to check thethermostat setting and see whether air isflowing from the supply outlets.

If,the investigator is not familiar withthe building or is responding to complaintsthat suggest a serious health problem, morepreparation may be needed before theinitial walkthrough. The activities listedbelow can be directed at a localized"problem area" or extended to include theentire building:

Collect easily-available information aboutthe history of the building and thecomplaints.

Identify known HVAC zones and com-plaint areas.

Begin to identify potential sources andpollutants (e.g., special use areas near thecomplaint location). Having a copy ofmechanical and floor plans can be helpfulat this stage, especially if they arereasonably up-to-date.

Notify the building occupants of theupcoming investigation.

Tell them what it means and what toexpect.

6?Diagnosing IAQ Problems 47

This improvised catch basinis intended to collect waterseeping into the buildingfrom below grade. Althoughthe catch basin "solves" theproblem of uncontrolledwater leakage, it also pro-vides an indoor locationthat could support thegrowth of microbiologicalsand create IAQ problems.

Identify key individuals needed for accessand information.

A person familiar with the HVAC systemsin the building should be available to assistthe investikitor at any time during theonsite phase. Individuals who havecomplained or who are in charge ofpotential sources (e.g., housekeeping, non-HVAC equipment) should be aware thattheir information is important and shouldbe contacted for appointments or telephoneinterviews if they will not be availableduring the onsite visit.

The initial walkthrough provides anopportunity to question complainants aboutthe nature and timing of their symptomsand to briefly examine the immediate areaof the complaint. The investigatorattempts to identify pollutant sources andtypes and observes the condition andlayout of the HVAC system serving thecomplaint area. Facility staff can be asked

48 Section 6 63

to describe the operating schedule ofequipment. Obvious problems (e.g.,blocked diffusers, malfunctioning airhandlers) can be corrected to see if thecomplaints disappear. The walkthroughcan solve many routine IAQ problems andwill suggest directions for a more complexinvestigation, should one be necessary.

Some investigators avoid taking anymeasurements during the initial walk-through so that they are not distracted from"getting the big picture." Others find thatusing smoke sticks, digital thermometers,and direct reading CO2 meters or detectortubes to take occasional measurementshelps them develop a feel for the building.

It may help to keep the followingquestions in mind during the initialwalkthrough:

Are there obvious pollutant sources? Dothey appear to be adequately controlled?

Are pollutant indicators present, such asodors, excessive dust, or staining?Are there sanitation problems (e.g.,debris near outdoor air intake, visiblemold growth, major water damage) thatcould be introducing air contaminants?Are there any conditions or activitiesoccurring in or near the building thatcould be related in timing, location, andhealth effects to the complaints?

Are there any deficiencies in the HVACsystem that serves the complaint area?

Does equipment serving the area (e.g.,thermostats, diffusers, fans, dampers,filters) appear to be operating, clean, andin good condition?Do operating procedures exist, and doesthe staff follow them?Do records indicate that the system wascommissioned (set, tested, and balanced)after construction?Do records indicate that system compo-nents are regularly inspected, calibrated,and adjusted?

Are there pathways and pressure differ-ences which could be moving contami-nants into the complaint area from theoutdoors or from other parts of thebuilding?

COLLECTING ADDITIONALINFORMATION

Additional information will be needed ifthe initial walkthrough does not identifythe cause of the problem. The followingpages present techniques for collectinginformation about the occupant com-

plaints, HVAC system, pollutant pathways,and pollutant sources and using that

information to develop a hypothesis thatcould explain the problem. Common sensewill suggest the appropriate sequence ofsteps during this part of the investigation.

For example, if the complaint is limited toa single room, it makes sense to evaluate

pollutant pathways into that room beforeattempting to inventory sources in loca-tions outside of, but connected to, the

complaint area. On the other hand, if thecomplaint involves a recognizable odor(e.g., exhaust fumes), it may be morepractical to begin by locating the potentialsource(s) of the odor before trying toidentify pollutant pathways.

Forms and checklists such as the

samples provided in this document (modi-fied if needed) can help investigators torecord information in an organized way.Small copies of basic floor plans, such as

fire evacuation plans, are convenient fornoting locations of observations.

Any instruments that will be usedshould be inspected to make sure they are

in working order and calibrated. IAQinvestigations generally include the use of,at a minimum: heatless chemical smokedevices and instruments for measuring

temperature and humidity.

Carbon dioxide measuring devices(detector tubes with 'a hand pump or adirect reading meter) are helpful for most

investigations. Other instruments may beneeded as the investigation progresses.

See Appendix A for additional guidance oncommon IAQ measurements.

Tools for Collecting Information

The following pages present strategies,

tools, and forms for the investigator to useduring an in-depth investigation. TheIncident Log shown below (and in Tab V)can be used to track the course of an inves-

tigation from the receipt of the originalcomplaint.


Sample FormIncident Log

Investigation Record(check the forms that were used)

FileNumber

Date ProblemLocation

e673 E

E gc.)

t 3al000 S

ta t.0600

36= e

e E>

013elt

e ..,g ro

-.. u.w4

r....z1 .-2.., y-wC.)

03 °= ..c

t..) .4D. p-

0 °a- 4:= -2,a :

° E.0 ._.o.a IL)..1:1 0x

Outcome /Comments

Log Entry By(initials)


COLLEC11NG OCCUPANT INFORMA110N

Strategies Tools

Review existinginformation aboutcomplaints

Existing RecordsIAQ Complaint FormIncident Log

Collect additionalinformation fromoccupants

Occupant InterviewOccupant Diary

An initial walkthrough mayuncover problems such asthis unsanitary condition inthe HVAC system. Birddroppings have collected inan air supply plenum nearan outdoor air intake thatwas not protected by abirdscreen.

The discussion that follows has beendivided into categories of occupant data,HVAC system data, pollutant pathwaydata, and source data. However, thesuggestions for collecting and usinginformation reflect the interdependence ofthese factors. For example, the operationof the air distribution system affectspollutant pathways, and the air distributiorsystem can also be a source of pollutants.

Indoor air quality related complaintsmay develop from a variety of causes.Neither the discussion of strategies forcollecting information nor the suggestionsfor interpreting data can present the fullrange of possible situations encountered in

50 Section 6 6 5

buildings. They are intended to present aproblem-solving approach that can helpfacility staff to understand and resolvemany common indoor air quality prob-lems. If you decide to hire outsideprofessionals to resolve your IAQ com-plaint, this discussion of strategies andtools should help you to understand andoversee their investigative work.

COLLECTING INFORMATIONABOUT OCCUPANTCOMPLAINTS

Occupant data falls into two categories:complaints of discomfort or other symp-toms (e.g., teary eyes, chills) and percep-tions of building conditions (e.g., odors,draftiness). Investigators can gathervaluable information about potentialindoor air problems by listening tooccupants, and use that information for:

defining the complaint area within thebuildingsuggesting directions for further investi-gation, either by identifying other eventsthat seem to happen at the same time asthe incidents of symptoms or discomfort,or by identifying possible causes for thetypes of symptoms or discomfort that areoccurringindicating potential measures to reduceor eliminate the problem

Review Existing Records ofComplaints

If there is a record of occupant complaints,a review of that record can help to definethe location of the IAQ problem andidentify people who should be interviewedas part of the investigation. Informationabout the history of complaints could alsostimulate theories about potential causes ofthe problem.

Interview Occupants

The most obvious way to collect informa-tion from building occupants is to talk to

them in person. If it is not possible tointerview everyone who has complainedabout building conditions, the investigatorshould attempt to interview a group ofindividuals that reflects the concerns of theaffected areas.

The investigation may also includeoccupant interviews with buildingoccupants who do not have complaints.Then conditions in the complaint area canbe compared to conditions in similarbuilding locations where there are nocomplaints.

A sample Occupant Interview form isshown here (there is another copy inTab V). It can also be presented in awritten form in order to get informationfrom more people than can be interviewed.The following key points will helpinterviews to be productive:

Read the discussion of evaluatingoccupant data before you conductinterviews to be certain that youunderstand what sort of information isneeded.Make a copy of the interview form foreach person you speak with, and use theform to record the answers to yourquestions.Choose a location in which the personyou are interviewing feels comfortable tospeak freely.Explain that the interview is intended tohelp discover and correct the cause of thecomplaints. Encourage the person youare interviewing to join in this coopera-tive problem-solving effort.Give the person you are interviewingenough time to think about your ques-tions.If complainants are reluctant to answerquestions about health symptoms,respect their desire for privacy. Planningfor how to maintain this privacy iswarranted, and in some cases may bemandated.Feel free to expand the interview byadding questions that help to improve

Sample FormOccupant Interview

SYMPTOM PATI-ERNSWhat kind of symptoms or discomfort are you experiencing?

Are you aware of other people with similar symptoms orconcerns? Yes No

If so, what are their names and locations?

Do you have any health conditions that may make you particularlysusceptible to environmental problems?

TIMING PATTERNSWhen did your symptoms start?

your understanding or explore theirhypotheses (or your own) about whatmay be causing the problem. Always beopen to answers that may not fit yourhypotheses.You may sometimes need to clarify aquestion by giving examples of the sortof information you are interested in. Tryto provide more than one example so thatyou don't seem to be telling the personthe answer you want. Be particularlycautious about mentioning specifichealth effects.

The Occupant Interview includesmany basic points that are found inquestionnaires used by professional IAQinvestigators. It is important to note,however, that this form is not called a"questionnaire." Formal questionnairesmay be useful for quantitative epidemiol-ogy. IAQ research, complex IAQ investi-gations. or when litigation is a possibility.In these cases, questionnaires must becarefully designed and executed by peoplewith an understanding of representativesampling and expertise in public health,industrial hygiene, or medicine. Use ofquestionnaires for such purposes is beyondthe scope or expertise of most in-house

66Diagnosing IAQ Problems 51


Sample FormOccupant Diary

On the form below, please record each occasion when youexperience a symptom of ill-health or discomfort that you thinkmay be related to an environmental condition in the building.

Time/Date Location Symptom Severity/Duration Comments

Sample FormLog of Activities and System Operation

On the form below, please record your observations of HVACsystem operation, maintenance activities, and any otherinformation that you think may be helpful in identifying the causeof IAQ complaints in this building. Please report any otherobservations (e.g., weather, other associated events) that you thinkmay be important as well.

Equipment and activities of particular interest:Air Handler(s):Exhaust Fan(s).Other Equipment or Activities.

Date/Time Day of Week Equipment Item/Activity Comments


52 Section 6

investigations; if such questionnaire data isneeded, building owners and managersshould use professionals.

Ask Occupants and FacilityStaff to Keep More DetailedRecords

Many events occur simultaneously in andaround a complex building, and it can bevery difficult to judge which of thoseevents might be related to the IAQcomplaints. In trying to resolve stubbornproblems, professional investigatorssometimes ask occupants and facility staffto keep day-by-day records. Occupants areasked to record the date and time ofsymptoms, where they are when thesymptoms appear, and any other informa-tion that might be useful. Such informa-tion could include observations about theseverity and duration of symptoms andcomments on weather conditions, events,and activities that are happening at thesame time. Facility staff are asked torecord the date and time of events such asmaintenance work, equipment cycles, ordeliveries. If symptoms seem to occur atparticular times of day, staff can focustheir attentions on recording eVents thatoccur before and during those periods.Such records are likely to produce moreaccurate and detailed information than canbe obtained by relying on memory. (Usethe Occupant Diary and the Log ofActivities and System Operation shownhere and included in Tab V.)

6 "

USING THE OCCUPANT DATA

The pattern of complaints within thebuilding helps to define the complaint area.The timing of symptoms and the types ofsymptoms reported may provide clues

about the cause of the problem.

Strategies for Using Occupant Data

Define the complaint area

Look for timing patternsLook for symptom patterns

_


4113, Erb

Exhaust fumes are drawninto this building's outdoorair intake when trucks areidling at the nearby loadingdock. Tools such as theOccupant Diary and Log ofActivities and SystemOperation can help toidentify intermittentpollutant sources such asthis one.

SPATIAL PArrERNS SUGGESTIONS

Widespread, no apparentspatial pattern

Check ventilation and tem-perature control for entirebuilding.Check outdoor air quality.Review sources that arespread throughout building(e.g., cleaning materials).Consider explanations otherthan air contaminants.

Localized (e.g., affectingindividual rooms, zones, orair handling systems)

Check ventilation and tem-perature control within thecomplaint area.Review pollutant sourcesaffecting the complaint area.Check local HVAC systemcomponents that may beacting as sources or distribu-tors of pollutants.

Individual(s) Check for drafts, radiant heat(gain or loss), and otherlocalized temperature controlor ventilation problems nearthe affected individual(s).Review local pollutantsource(s) near the affected

Consider that commonbackground sources mayaffect only susceptibleindividuals.Consider the possibility thatindividual complaints mayhave different causes that arenot necessarily related to thebuilding (particularly ifsymptoms differ among theindividuals).

54 Section 6

Define the Complaint Area

Use the spatial pattern (locations) ofcomplaints to define the complaint area.Building locations where symptoms ordiscomfort occur define the rooms or zonesthat should be given particular attentionduring the initial investigation. However,the complaint area may need to be revisedas the investigation progresses. Pollutantpathways can cause occupant complaintsin parts of the building that are farremoved from the source of the problems.

6 9

Look for Timing Patterns

Look for patterns in the timing of com-plaints. The timing of symptoms andcomplaints can indicate potential causesfor the complaints and provide directionsfor further investigation. Review the datafor cyclic patterns of symptoms (e.g.,worst during periods of minimum ventila-tion or when specific sources are mostactive) that may be related to HVACsystem operation or to other activities inand around the building.

TIMING PATTERNS SUGGESTIONS

Symptoms begin and/orare worst at the start ofthe occupied period

Review HVAC operatingcycles. Emissions frombuilding materials, or from theHVAC system itself, may buildup during unoccupied periods.

Symptoms worsen overcourse of occupied period

Consider that ventilation maynot be adequate to handleroutine activities or equipmentoperation within the building.

Intermittent symptoms Look for daily, weekly, orseasonal cycles or weather-related patterns, and checklinkage to other events in andaround the building.

Single event of symptoms Consider spills, otherunrepeated events as sources.

Recent onset of symptoms Ask staff and occupants todescribe recent changes orevents (e.g., remodeling,renovation, redecorating,HVAC system adjustments,leaks, or spills).

Symptoms relieved on leavingthe building, either immedi-ately, overnight, or (in somecases) after extended periodsaway from the building

Consider that the problem islikely to be building-related,though not necessarily due toair quality. Other stressors(e.g., lighting, noise) may beinvolved.

Symptoms never relieved,even after extended absencefrom building (e.g., vacations)

7 0

Diagnosing IAQ Problems 55

Consider that the problemmay not be building-related.

The following chart listssome common symptomgroups that can be relatedto indoor air quality, alongwith possible sources orcauses of those symptoms.Building managers arecautioned that this is only apartial listing.

Look for Symptom Patterns

Look for patterns in the types of symptomsor discomfort. IAQ investigations oftenfail to prove that any particular pollutantor group of pollutants are the cause of theproblem. Such causal relationships areextremely difficult to establish. There islittle information available about the healtheffects of many chemicals. Typical indoorlevels are much lower than the levels at

which toxicology has found specificeffects. Therefore, it may be more usefulto look for patterns of symptoms thanfor specific pollutant and health effectrelationships.

Investigators who are not medicallytrained cannot make a diagnosis and shouldnot attempt to interpret medical records.Also, confidentiality of medical informa-tion is protected by law in some jurisdic-tions and is a prudent practice everywhere.

SYMPTOM PATTERNS SUGGESTIONS

THERMAL DISCOMFORT Check HVAC condition and operation.Measure indoor and outdoor temperature and humidity (see Figure 6-2 onthe opposite page). See if extreme conditions exceed design capacity ofHVAC equipment.Check for drafts and stagnant areas.Check for excessive radiant heat gain or loss.

COMMON SYMPTOM GROUPSHeadache, lethargy, nausea,drowsiness, dizziness

If onset was acute (sudden and/or severe), arrange for medical evaluation,as the problem may be carbon monoxide poisoning.

Check combustion sources for uncontrolled emissions or spillage. Checkoutdoor air intakes for nearby sources of combustion fumes.Consider evacuation/medical evaluation if problem isn't corrected quickly.Consider other pollutant sources.Check overall ventilation; see if areas of poor ventilation coincide withcomplaints.

Congestion; swelling, itching orirritation of eyes, nose, orthroat; dry throat; may beaccompanied by non-specificsymptoms (e.g. headache,fatigue, nausea)

May be allergic, if only small number affected; more likely to be irritationalresponse if large number are affected.

Urge medical attention for allergies.Check for dust or gross microbial contamination due to sanitationproblems, water damage, or contaminated ventilation system.Check outdoor allergen levels (e.g., pollen counts).Check closely for sources of irritating chemicals such as formaldehyde orthose found in some solvents.

Cough; shortness of breath;fever, chills and/or fatigue afterreturn to the building

May be hypersensitivity pneumonitis or humidifier fever. A medicalevaluation can help identify possible causes.

Check for gross microbial contamination due to sanitation problems, waterdamage, or contaminated HVAC system.

Diagnosed infection May be Legionnaire's disease or histoplasmosis, related to bacteria or fungifound in the environment.

Contact your local or State Health Department for guidance.

Suspected cluster of rare orserious health problems suchas cancer, miscarriages

Contact your local or State Health Department for guidance.

OTHER STRESSORSDiscomfort and/or healthcomplaints that cannot bereadily ascribed to air contami-nants or thermal conditions

Check for problems with environmental, ergonomic, and job-relatedpsychosocial stressors.

56 Section 671

Figure 6-2 shows the range of tempera-tures and relative humidities that fallwithin the comfort zone for most individu-als dressed in "typical" clothing andinvolved in light, mostly sedentaryactivity. Recent research suggests thatindoor air quality is judged to be worse astemperatures rise above 76°F, regardless of

the actual air quality.There is considerable debate among

researchers, IAQ professionals, and healthprofessionals concerning recommendedlevels of relative humidity. In general, therange of humidity levels recommended bydifferent organizations seems to be 30% to60% RH. Relative humidities below thislevel may produce discomfort fromdryness. On the other hand, maintainingrelative humidities at the lowest possiblelevel helps to restrict the growth of moldand mildew. The concerns (comfort forthe most part) associated with dry air mustbe balanced against the risks (enhancedmicrobiological growth) associated withhumidification. If temperatures aremaintained at the lower end of the comfortrange (68 70°F) during heating periods,relative humidity in most climates will notfall much below 30% (also within thecomfort range) in occupied buildings.

COLLECTING INFORMATIONABOUT THE HVAC SYSTEM

IAQ complaints often arise because thequantity or distribution of outdoor air isinadequate to serve the ventilation needs ofbuilding occupants. Problems may also betraced to air distribution systems that areintroducing outdoor contaminants ortransporting pollutants within the building.

The investigation should begin with thecomponents of the HVAC system(s) thatserve the complaint area and surroundingrooms, but may need to expand if connec-tions to other areas are discovered. Yourgoal is to understand the design andoperation of the HVAC system well

FIGURE 6-2: Acceptable Ranges of Temperature and RelativeHumidity During Summer and Winter '

Relative Humidity Winter Temperature Summer Temperature

30% 68.5°F - 76.0°F 74.0°F 80.0°F

40% 68.5°F - 75.5°F 73.5°F 79.5°F

50%2 68.5°F - 74.5°F 73.0°F - 79.0°F

60% 68.0°F - 74.0°F 72.5°F 78.0°F

' Applies for persons clothed in typical summer and winter clothing, at light,mainly sedentary activity.2 See left for discussion of relative humidities.

SOURCE: Adapted from ASHRAE Standard 55-1981, Thermal Environmen-tal Conditions for Human Occupancy

enough to answer the following questions:

Are the components that serve theimmediate complaint area functioningproperly?Is the HVAC system adequate for thecurrent use of the building?Are there ventilation (or thermal com-fort) deficiencies?Should the definition of the complaintarea be expanded based upon the HVAClayout and operating characteristics?

An evaluation of the HVAC systemmay include limited measurements oftemperature, humidity, air flow, and CO2,as well as smoke tube observations.Complex investigations may require moreextensive or sophisticated measurements ofthe same variables (e.g., repeated CO2measurements taken at the same locationunder different operating conditions,continuous temperature and relativehumidity measurements recorded with adata logger). A detailed engineering studymay be needed if the investigation discov-ers problems such as the following:

airflows are lowHVAC controls are not working or areworking according to inappropriatestrategiesbuilding operators do not understand (orare unfamiliar with) the HVAC system


WHAT DO YOUKNOW SO FAR?

Use the HypothesisForm on page 223 tomake brief notes afterreviewing the occupantdata.

Decide whether youhave a hypothesis thatmight explain thecomplaints. If so, testit. (See page 78 for adiscussion ofhypothesis testing.)

Decide what else youneed to know.Consider whetherin-house expertise issufficient or outsideassistance is needed.(See Section 8 forguidance on hiringoutside assistance.)

COLLECTING HVAC SYSTEM INFORMATION

Strategies Tools

Review existing docu-mentation on HVACdesign, installation, andoperation

Collect:

design documents, testing andbalancing reportsoperating instructions, controlmanufacturer's installation data

Talk to facilities staff Ask facilities staff to record theirobservations of equipment cycles,weather conditions, and other eventsusing Log of Activities and SystemOperations

Inspect system layout,condition, and operation

Use:

Zone/Room RecordHVAC Checklist - Short Form and/orHVAC Checklist - Long Formthermometer and sling psychrom-eter (or electronic equivalent) tomeasure temperature and humiditymicromanometer (or equivalent) tomeasure pressure differentials

0-2" and 0-10° water gauge (w.g.)to measure at fans and intakes

0-.25" w.g. with pitot tube to checkairflow in ducts

chemical smoke for observingairflow patternsa device to assess airflow fromdiffusers

rough quantitative: anemometer;velometeraccurate quantitative: flow hood

carbon dioxide measurementdevices

detector tubes with a hand pumpdirect reading meter

Use additional instru-ments as appropriate

Instruments often used by profes-sional IAQ consultants include:

a hygrothermograph to log tempera-ture and humiditytracer gas and measurementequipmenta device to measure airborneparticulatesmeasurement devices for carbonmonoxide and other contaminantsof interest

58 Section 6

Review Documentation onHVAC Design, Installation, andOperation

A review of existing documentation (e.g.,plans, specifications, testing and balancingreports) should provide information aboutthe original design and later modifications,particularly:

the type of HVAC system (e.g., constantvolume, VAV)locations and capacities of HVACequipment serving the complaint areathe planned use of each building areasupply, return, and exhaust air quantitieslocation of the outdoor air intake and ofthe supply, return, and exhaust registers,diffusers, and grilles that serve thecomplaint area

The most useful way to record thisinformation is to make a floor plan of thecomplaint area and surrounding rooms.You may be able to copy an existing floorplan from architectural or mechanicaldrawings, fire evacuation plans, or someother source.

If there is no documentation on themechanical system design, much more on-site inspection will be required to under-stand the HVAC system. The HVACsystem may have been installed ormodified without being commissioned,so that it may never have performedaccording to design. In such cases, goodobservations of airflow and pressuredifferentials are essential. In addition, loadanalyses may be required.

Talk to Facility Staff

Facility staff can provide important currentinformation about equipment operating andmaintenance schedules and breakdowns orother incidents. There may be inspectionreports or other written records availablefor review. Staff members who arefamiliar with building systems in generaland with the specific features of the

7 3

building under investigation can be veryhelpful in identifying conditions that mayexplain the indoor air quality complaints.Some facility operators have extensivepreventive maintenance programs. On theother hand, discussion could reveal thatfacility staff are not operating the buildingaccording to its design, because:

they do not understand the design logicof the HVAC systemthey have been asked to run the HVACsystem at the lowest possible energy costthey do not have the manpower tooperate the building properlythe HVAC system has not been modifiedto accommodate changes in the use ofspace or increases in the occupantpopulation

Staff may have noticed occupantactivities that are indicators of inadequateventilation or poorly controlled tempera-tures, such as:

desktop fans, heaters, or humidifierssupply diffusers blocked off with tape or

cardboardpopped-up ceiling tilesinterference with thermostat settings

IAQ complaints are often intermittent.Discussions with staff may reveal patternsthat relate the timing of complaints to thecycles of equipment operation or to otherevents in the building such as painting,installation of new carpeting, or pestcontrol. These patterns are not necessarilyobvious. Keeping a day-to-day record mayhelp to clarify subtle relationships betweenoccupant symptoms, equipment operation,and activities in and around the building.(See Occupant Diary and Log ofActivities and System Operations onpage 52 and in Tab V.) Staff membersmay have theories about the cause ofthe problem.

Inspect System Layout,Condition, and Operation

If the building is new or if there is a pre-ventive maintenance program with recent

1.1-_

Above: An investigation of this buildingrevealed no problems with the HVACsystem, although the amount of outdoorair was very low. In a more thoroughinspection of the HVAC system, investi-gators found that the wiring to this out-door air damper motor had never beenconnected. No outdoor air was enteringthe building through the intake controlledby this damper. Below: These investiga-tors are examining a perimeter fan-coilunit. Self-contained heating or coolingunits such as this one are often over-looked during routine maintenance.There may be many such units in a singlebuilding, sometimes in remote or inac-cessible locations.

Diagnosing 1AQ Problems 59

The design specificationsfor this building called for aminimum 20% setting onthe outdoor air dampercontrol. Facility staff low-ered the minimum outdoorair setting to 10% in orderto save energy and reduceoperating costs. As a re-sult, the building wasunderventilated wheneveroutdoor temperatures wereeither very hot or very cold.

MM.

test and balance reports, it is possible (butnot necessarily likely) that the HVACsystem is functioning according to itsoriginal design. Otherwise it is probablethat one or more features of building usageor system operation have changed in waysthat could affect indoor air quality.

Elements of the on-site investigationcan include (but are not limited to) thefollowing:

Check temperature andlor humidity to seewhether the complaint area is in the com-

fort range.

Take more than one measurement to ac-count for variability over time and fromplace to place. Compare to Figure 6-2 onpage 57 (see also Appendix B ).

Check thermostat operation.Check whether the supply air tempera-ture corresponds to the design criteria.Use a hygrothermograph (if available) tolog temperature and humidity changes inthe complaint area.

60 Section 6

Check for indicators of inadequateventilation.

Check supply diffusers to see if air ismoving (using chemical smoke). If it isnot, confirm that the fan system is operat-ing, and then look for closed dampers,clogged filters, or signs of leaks.Compare design air quantities (if avail-able) to building codes for the currentoccupancy or ventilation guidelines (e.g.,ASHRAE 62-1989, see Appendix B). Ifthe HVAC system, performing as de-signed, would not provide enough venti-lation air for current needs, then there isgood reason to believe that actual ventila-tion rates are inadequate.Measure carbon dioxide (CO2) in thecomplaint area to see whether it indicatesventilation problems. (See Appendix Afor a discussion of techniques for measur-ing and interpreting CO2 concentrations.)Measure air quantities supplied to andexhausted from the complaint area, in-cluding calculation of outdoor air quanti-ties (see Appendix A for further guid-ance). Be aware of damper settings andequipment cycles when you are measur-ing (e.g., are you evaluating minimumoutdoor air, "normal" conditions, ormaximum airflow?). Note that evalua-tion of variable air volume (VAV) sys-tems requires considerable expertise.Compare the measured air quantities toyour mechanical system design specifica-tions and applicable building codes. Alsocompare ventilation rates to ASHRAE62-1989. Some of the ventilation recom-mendations of ASHRAE 62-1989 arereproduced in Appendix B.

Check that equipment serving the com-plaint area (e.g., grilles, diffusers, fans) isoperating properly.

Confirm the accuracy of reported operat-ing schedules and controls sequences; forexample, power outages may have dis-rupted time clocks, fans reported as"always running" may have been acci-dentally switched off, and controls can bein need of calibration.

7 5

Check to see that equipment is properlyinstalled. For example, look for shippingscrews that were never removed or fansthat were reversed during installation, sothat they move air in the wrong direc-tion.

Compare the current system to theoriginal design.

Check to see that all equipment calledfor in the original design was actuallyinstalled.See whether original equipment mayhave been replaced by a different model(i.e., a model with less capacity or differ-ent operating characteristics).

See whether the layout of air supplies,returns, and exhausts promotes efficientair distribution to all occupants andisolates or dilutes contaminants.

(See Appendix A for guidance on usingchemical smoke to study airflow and mix-ing patterns and CO, to help determine theadequacy of ventilation.)

If supplies and returns are close together,heatless chemical smoke can be used tocheck for short-circuiting (supply air thatdoes not mix properly with air in thebreathing zone, but moves directly to thereturn grille). CO2 can also be used toevaluate air mixing.Use heatless chemical smoke to observeairflow patterns within the complaintarea and between the complaint area andsurrounding spaces, including outdoors.Compare airflow directions under vari-ous operating conditions.If the system layout includes ceilingplenums, look above the ceiling for inter-ruptions such as walls or full-heightpartitions.

Consider whether the HVAC system itselfmay be a source of contaminants.

Check for deterioration or unsanitaryconditions (e.g., corrosion, water damageor standing water, mold growth or exces-

sive dust in ductwork, debris or damagedbuilding materials in ceiling plenums).If the mechanical room serves as a mix-ing plenum (i.e., return and outdoor airare drawn through the room into the airhandler), check very carefully for poten-tial contaminants such as stored solventsand deteriorated insulation.

Use the forms provided in this documentto inspect the HVAC system.

Use the Zone/Room Record to describethe ventilation system serving the com-plaint area and surrounding rooms orzones. The Zone/Room Record isreproduced on page 62 and in Tab V.Use the HVAC Checklist (short and/orlong form) to evaluate the condition ofHVAC system components that affect airdistribution and IAQ in the complaintarea. A portion of the HVAC Checklist-Short Form is reproduced on page 62.The HVAC Checklist - Long Form isuseful for more detailed examination ofthe system. Complete copies of bothforms can be found in Tab V.

7 6


Thedark streaks at theoutlet of this supply diffusercould indicate a filtrationproblem. Poorly maintainedor improperly sized filterscan allow dirt to be distrib-uted through the building.

Sample Form

Zone/Room Record

This form is to be used differently depending on whether the goal is to prevent or diagnose IAQ problems.During development of a profile, this form should be used to record more general information about the entirebuilding; during an investigation, the form should be used to record more detailed information about thecomplaint area and areas surrounding the complaint area or connected to it by pathways.

PROFILE AND DIAGNOSIS INFORMATION DIAGNOSIS INFORMATION ONLY

Building Area(Zone/Room)

Use** Source ofOutdoor Air*

MechanicalExhaust?

(Write "No"or estimatecfm airflow)

Comments Peak Number ofOccupants or

Sq. Ft. Floor Area**

Total AirSupplied

(in cfm)***

Outdoor AirSupplied

per Person orper 150 Sq.Ft. Area****

Sample Form

HVAC Checklist Short Form

Sections 2, 4 and 6 and Appendix B discuss the relationships between theHVAC system and indoor air quality.

MECHANICAL ROOM

Clean and dry? Stored refuse or chemicals?

Describe items in need of attention

MAJOR MECHANICAL EQUIPMENT

Preventive maintenance (PM) plan in use?

Control System

Type

System operation


62 Section 6

USING THE HVAC SYSTEMDATA

As you review the HVAC data, considerwhether the system is adequate to servethe use of the building and whether thetiming, location, and impact of apparentdeficiencies appear related to the IAQcomplaint. Deficiencies in HVACdesign, operation, or maintenance mayexist without producing the complaintunder investigation; some defects maynot cause any apparent IAQ problems.

Strategies for Using the HVACSystem Data

Compare the original design to thecurrent system.

Compare the original uses of space tocurrent uses.

Consider the condition of the HVACsystem.

77

HEALTH AND SAFETY CONSIDERATIONS FOR!AG INVESTIGATORS

Normal safety precautions observed during routine operation of the buildingmust be followed closely during IAQ inspections. When the IAQ investigator isnot familiar with the mechanical equipment in that particular facility, an operatoror engineer should be present at all times in equipment areas. Potential safetyhazards include:

electrocutioninjury from contacting fans, belts, dampers or slamming doorsburns from steam or hot water linesfalls in ventilation shafts or from ladders or roofs

Investigators evaluating building IAQ generally do not encounter situations inwhich specific personal protection measures (e.g., protective garments andrespirators) are required. However, safety shoes and eyeglasses are generallyrecommended for working around mechanical equipment. When severe con-tamination is present (e.g., microbiological, chemical, or asbestos), IAQ investi-gators may need additional protection in the vicinity of certain building areas orequipment. Such decisions are site-specific and should be made in consultationwith an experienced industrial hygienist. General considerations include thefollowing:

Microbiological: Care must be taken when serious building-related illness(e.g., Legionnaire's disease) is under investigation or when extensive microbio-logical growth has occurred. Investigators with allergy problems should beespecially cautious. The array of potential contaminants makes it difficult toknow what sort of personal protection will be effective. At a minimum, investiga-tors should minimize their exposure to air in the interior of ducts or other HVACequipment unless respiratory protection is used. If there is reason to suspectbiological contamination (e.g., visible mold growth), expert advice should beobtained about the kind of respiratory protection to use and how to use it.Possible protective measures against severe microbiological contaminationinclude disposable coveralls and properly fitted respirators.

Chemical: Where severe chemical contamination is suspected, specific precau-tions must be followed if OSHA action levels are approached. Such instancesrarely occur in IAQ investigations. One possible exception might be a pesticidespill in a confined space. In this case, an appropriate respirator and disposablecoveralls may be needed.

Asbestos: An IAQ investigation often includes inspection above accessibleceilings, inside shafts, and around mechanical equipment. Where materialsuspected of containing asbestos is not only present, but also has depositedloose debris, the investigator should take appropriate precautions. This mightinclude disposable coveralls and a properly fitted respirator.

Note: The requirements for proper fit, physical condition of the wearer, and otherconsiderations involved in selection of the proper respirator must be evaluated by anoccupational safety and health specialist. There is a NOSH Respirator Decision Logic forproper respirator selection, and OSHA has regulations for an appropriate respiratorprotection program.


When the IAQ investi-gator is not familiarwith the mechanicalequipment in thatparticular facility, anoperator or engineershould be present atall times in equipmentareas.

SUGGESTIONS

Revise definition of complaint area(if needed) to add spaces linked tothe original complaint area byductwork or controls.

Check to see that thermostatsare properly located and functionproperly.

Note equipment changes thatcould be affecting the system'sperformance (e.g., removal oraddition of equipment, replacementby a different model).

Review operating procedures foroccupied and unoccupied periods.

Compare timing of occupied/unoccupied periods to equipmentcycles and occupant complaints.Confirm that time clocks arereading the actual time. SeeASHRAE 62-1989 for suggested leadtimes to allow proper flushingbefore occupants arrive. In somecases (e.g., warm, humid climates),fans may need to operate duringunoccupied periods to preventmold growth or other problems.

64 Section 6

Compare the Original Design tothe Current HVAC System

Consider the original HVAC design andcompare it to the current equipment,layout, and controls. A variety of HVACsystem designs have been used in publicand commercial buildings. The type ofsystem used in your building affects thecontrol of ventilation air quantities anddistribution, as well as thermal comfort.See Appendix B for a discussion of HVACsystem types.

7 9

Use HVAC Data to EvaluateMitigation Measures

As you use the HVAC data to evaluatepotential mitigation measures, review thesuggestions made in both the box on thefacing page for all HVAC systems and inthe box on this page for the type of HVACsystem in your building.

SYSTEM TYPES SUGGESTIONS

No mechanicalventilation orexhaust only

Identify the source(s) of ventilationair (e.g., operable windows, doorspropped open).Check whether the location of openwindows, doors, or other openingspromotes the introduction of odorsor contaminants.

Room units(e.g., unitventilators)

Check whether outdoor air intakesare obstructed. Does their locationpromote the introduction of odorsor contaminants?Note design airflows in thecomplaint area (outdoor air, supply,return, and exhaust) and surround-ing spaces; compare to ASHRAE62-1989 and to actual measuredairflows.

Constantvolume

Note design airflows in thecomplaint area (outdoor air, supply,return, and exhaust) and surround-ing spaces; compare to applicablebuilding codes, ASHRAE 62-1989,and to actual measured airflows.Check whether outdoor air intakesare obstructed. Does their locationpromote the introduction of odorsor contaminants? Check forunsanitary conditions.Check outdoor air damper controls.

Variableair volume(VAV)

8 0

Diagnosing 1AQ Problems 65

In addition to all suggestions madefor constant volume systems:

Confirm whether the system designallows regulation of outdoor airquantities. Do VAV boxes havestops to ensure that minimumamounts of outdoor air are deliv-ered at all times during occupiedperiods? Are the system controlsproviding a constant ventilation rateper person regardless of total sys-tem airflows?Observe changes (if any) in airflowpatterns within and around thecomplaint area as the VAV systemthrottles from maximum tominimum flow.

ROOM USE CHANGES SUGGESTIONS

Increased occupantdensity

Compare temperature and humidityto comfort zone in ASHRAE 55-1981guidelines.Compare minimum outdoor airquantities to the original design,applicable building codes, andASHRAE 62-1989 guidelines.

Change in type ofoccupant population

Example: Introduction of a morephysically active group of occupantscan change thermal comfort require-ments.

Compare temperature and humidityto comfort zone in ASHRAE 55-1981guidelines.Compare minimum outdoor airquantities to the original design,applicable building codes, andASHRAE 62-1989 guidelines.Check for low-level contaminantsources.

Additional non-HVACequipment

Compare temperature and humidityto comfort zone in ASHRAE 55-1981guidelines.Consider the need for local exhaustat point sources of contaminants.

Conversion to or addi-tion of special uses

Example: Modifications that convertor add such special uses as smokinglounges, print shops, or kitchenfacilities may also require changes inthe operation of the HVAC system.

Check pressure relationshipsbetween special use areas andsurrounding spaces.Consider the need for local exhaustat point sources of contaminants.

Rearrangement of workstations (e.g., relocationof partitions)

Check that thermostats are properlylocated. Compare temperature andhumidity to comfort zone inASHRAE 55-1981 guidelines.Check layout of supplies, returns,and exhausts.Check to make sure that partitionsdo not block proper air circulation.

66 Section 6

8i

Compare the Original Uses ofSpace to Current Uses

Compare the original uses of the complaintarea and surrounding rooms to currentuses of those areas. Indoor air qualityproblems often arise when the usage ofrooms changes without correspondingadjustments to the HVAC system. Forexample, if ventilation appears to be aproblem despite a properly functioningHVAC system, the existing system maybe inadequate to meet current needs.

Consider the Condition of theHVAC System

Consider whether the HVAC system isreasonably clean and functioning properly.Review the results of the onsite inspection.If you identified sanitary or operatingproblems in the HVAC system serving thecomplaint area, you may want to correctthose problems and see whether thecomplaints are resolved before continuingwith the investigation.

SYSTEM CONDITIONS SUGGESTIONS

Unsanitary conditionsMoisture or standing waterDebrisDust and/or mold growth

Correct sanitary problems andadopt necessary measures toprevent recurrence of prob-lems.

HVAC malfunctionsEquipment breakdownObstructed diffusers or grillesAir distribution or mixingproblems: (e.g.,equipment isout of balance, requirescalibration, or needs otheradjustment)Air bypasses filters (due toloose filter tracks, incorrect filtersize, or filter overloaded withdirt)Air distribution system leaks(e.g., leaky ductwork; unin-tended openings in pressurizedceilings or in return air plenums)

Evaluate whether the HVACdefect could have caused theIAQ complaint.Correct the malfunction(s),and see whether complaintsare resolved.Review maintenance programand revise as needed toprevent future problems.

HVAC functions properly.However, there is evidence ofunderventilation.

82


Consider what adjustmentscould be made to increase thesupply of outdoor air (ordecrease the ventilationdemand) in the complaintarea.


Use the HypothesisForm on page 223 tomake brief notesafter reviewing theHVAC data.Decide whether youhave a hypothesisthat might explainthe complaints. Ifso, test it. (See page78 for a discussionof hypothesistesting.)Decide what elseyou need to know.Consider whether in-house expertise issufficient or outsideassistance is needed.(See Section 8 forguidance on hiringoutside assistance.)

COLLECTING INFORMATIONABOUT POLLUTANT PATHWAYSAND DRIVING FORCES

Unless the IAQ problem is caused by anobvious contaminant located in thecomplainant's immediate workspace, youwill need to understand the patterns ofairflow into and within the complaint area.Correction of IAQ problems often involvescontrolling pollutant movement throughsealing of pollutant pathways or manipula-tion of the pressure relationships.

If the complaints being investigated arelimited to a few areas of the building, pollut-ant pathways can be evaluated so that thecomplaint area is properly defined beforeconducting the source inventory. If com-plaints are spread throughout the building,

COLLECTING PATHWAY INFORMATION

Strategies Tools

Identify pollutantpathways

Architectural and mechanicaldrawingsPollutant Pathway Form for InvestigationsSketch plan of complaint area

Observe directionof air movement

Chemical smoke is beingused to detect the directionand amount of airflowthrough this closeddoorway. A buildinginvestigator must knowhow the ventilation in thebuilding is designed tooperate in order to decidewhether the observed flowof smoke is appropriate.

Testing and balancing reportsChemical smoke testsMicromanometer or equivalent

68 Section 6 8 3

evaluation of pathways could be a verytime-consuming process, and it may bemore practical to look for major contami-nant sources before trying to discover howthe contaminants move within the building.

Identify Pollutant Pathways

Architectural and mechanical pathwaysallow pollutants to enter the complaint areafrom surrounding spaces, including theoutdoors. An examination of architecturaland mechanical plans can help in develop-ing a list of connections to surroundingareas. These include:

doorsoperable windowsstairwayselevator shaftsutility chasesductwork and plenumsareas served by common HVAC controls(e.g., shared thermostats)

Onsite inspection is needed to confirmthe existence of these connections and toidentify other openings (e.g., accidentalopenings such as cracks and holes). Firecodes usually require that chases and hid-den openings be firestopped. Check for theexistence and condition of firestops inchases, especially those that connect bothvertically and horizontally.

The Pollutant Pathway Form forInvestigations shown to the right can beused along with a sketch plan of thecomplaint area (similar to the example onpage 70) to record pathways and directionsof pollutant movement. A blank copy ofthe form is included in Tab V.

Observe Air MovementDirection

The airflow quantities shown in mechani-cal plans or in testing and balancingreports can be used to determine thedirection of air movement intended by thedesigner. Onsite examination is necessaryto determine the actual direction of airflowat each available pathway.

Chemical smoke tubes can be used todetermine airflow directions between thecomplaint area and surrounding spaces(including the outdoors), and to reveal aircirculation patterns within the complaintarea. A micromanometer (or equivalent)can measure the magnitude of pressuredifferences between these areas. Thesketch plan and the Pollutant PathwayForm for Investigations can be used torecord the results.

It may be necessary to make observa-tions under different conditions, as airflowdirection can change depending uponweather conditions, windspeed anddirection, equipment operation within thebuilding, traffic through doors, and otherfactors (e.g., as VAV systems throttleback). Switching air handlers or exhaustfans on and off, opening and closing doors,and simulating the range of operatingconditions in other ways can help to showthe different ways that airborne contami-nants move within the building. Dusttracking patterns around door frames canreveal the dominant direction of air andpollutant movement.

Some investigators study air movementby releasing a small amount of peppermintoil at the opening to a suspected pathwayand asking an assistant to sniff for the

Sample Form

Pollutant Pathway Form for Investigations

This form should be used in combination with a floor plan such as a fireevacuation plan.

Building areas that appear isolated from each other may be connected byairflow passages such as air distribution zones, utility tunnels or chases, partywalls, spaces above suspended ceilings (whether or not those spaces areserving as air plenums), elevator shafts, and crawl spaces.

Rooms or ZonesConnected to the

Complaint Area byPathways

UsePressure Relative to

Complaint AreaComments

(e.g., potentialpolluntantsources)+/- date/time

"toothpaste" smell. If this technique isused, it is important that the assistant havean acute sense of smell. If the building isin use during the investigation, occupantsmay also notice the odor and could find itdistracting. Some investigators prefer touse methods that release an odor duringunoccupied periods. Investigators shouldnote two common causes of false negativeresults (falsely concluding that no pathwayexists):

The nose quickly becomes tolerant ofstrong odors, so that the assistant mayneed to take a long rest (breathing freshair) between tests.If there is substantial airflow through thepathway, the peppermint oil odor couldbe diluted so that it is imperceptible.

Tracer gases such as sulfur hexafluo-ride (SF,) can provide qualitative andquantitative information on pollutant path-ways and ventilation rates. Use of tracergases to obtain quantitative resultsrequires considerable technical expertise.If it appears that a sophisticated study ofpathways (or ventilation rates) is required,you need to use trained investigators.



Vestibule

ReceptionArea

ei7Al2.41,0tz

Elevator Bank

Office

ConferenceRoom

(77bit}Q-urrif

(71-fruAA.e-

Lounge

(ID

Bathroom

Computer Room

USING POLLUTANT PATHWAYDATA

Pollutant pathway information helps theinvestigator to understand airflow patternsin and around the complaint area. Thepollutant pathway data may indicate a needto enlarge the complaint area, or may directattention toward contaminant sources thatdeserve close study.

Strategies for Using PathwayInformation

Evaluate airflow patternsConfirm or revise boundaries of the com-plaint area

MechanicalRoom

oc,SupplyStorage

0 ice

70 Section 6

The receptionist and office occupants inZone 1 have complained of food odors.The investigator is using a fire escapeplan to record air movement, sources,and complaint information. The inves-tigator has noted one hypothesis aboutthe cause of the complaints in the roommarked "Lounge."

8 5

Evaluate Airflow Patterns

Evaluate airflow patterns into andwithin the complaint area. Because ofthe complexity and variability of air-flow patterns, investigators cannot beexpected to understand how air moveswithin the building under all potentialoperating conditions. However, dataon pathways and driving forces can

help to locate potential pollutantsources and to understand how con-

taminants are transported to building

occupants.

Confirm or Revise Boundariesof the Complaint Area

The discovery of unexpected pollutantpathways can show a need to study

areas of the building that may bedistant from the original complaintarea.

AIRFLOW PATTERNS SUGGESTIONS

Onsite observations Look for temporal patternslinking changes in airflowdirection to incidents ofcomplaints.Look for spatial patternslinking potential sources tothe locations of complaints.

COMPLAINT AREA SUGGESTIONS

Complaint area connectedby architectural features toother areasComplaint area connectedby mechanical system toother areasUnintentional pathways(e.g., cracks, holes)

SG


Check whether pressure relation-ships between complaint area andsurrounding locations followsintent of ventilation design.Check whether air from otherlocations flows into the complaintarea under some conditions. If so,consider expanding the investiga-tion to inventory pollutant sources(and perhaps collect HVAC oroccupant data) in those locations.


Use the HypothesisForm on page 223 tomake brief notes afterreviewing the pollutantpathway data.Decide whether youhave a hypothesis thatmight explain thecomplaints. If so, testit. (See page 78 for adiscussion of hypoth-esis testing.)Decide what else youneed to know. Con-sider whether in-houseexpertise is sufficientor outside assistance isneeded. (See Section 8for guidance on hiringoutside assistance.)

COLLECTING SOURCE INFORMATION

Strategies Tools

Conduct onsite Pollutant and Source Inventoryinspection Chemical Inventory

Talk with buildingoccupants, facilitiesstaff, and contractors

Pollutant and Source InventoryChemical Inventory

Sample FormPollutant and Source Inventory

Using the list of potential source categories below, record anyindications of contamination or suspected pollutants that mayrequire further investigation or treatment.

Source Category Checked Needs Attention Location Comments

SOURCES OUTSIDE THE BUILDING

Contaminated Ambient Air

Pollen, dustIndustrialcontaminantsGeneral vehicularcontaminants

Sample FormChemical Inventory

The inventory should include chemicals stored or used in thebuilding for cleaning, maintenance, operations, and pest control.

Date Chemical/Brand Name

Use StorageLocation(s)

MSDSon File?


72 Section 6

COLLECTING INFORMATION ONPOLLUTANT SOURCES

Throughout the investigation, the buildinginvestigator will try to identify pollutantsources that may be causing the occupantcomplaints. Any public or commercialbuilding is likely to contain a number ofsources that produce odors, contaminants,or both. The investigator's task is toidentify the source(s) that may be respon-sible for the complaint(s).

The area included in the pollutant sourceinventory should be defined by the invest-igator's understanding of the building'sarchitectural and mechanical layout andpollutant pathways. Common sense willhelp to differentiate unusual sources (e.g.,spills, strong odors from new furnishingsor equipment) from those that are normallyfound within or near the building.

Remember that very few sources ofindoor air contaminants are both continu-ous and constant in volume over time.Pollutant concentrations often vary instrength over time, and may not be evidentat the time of the site visit. Some sourcesare subtle and might only be noticed by atrained investigator. As the investigationprogresses, the inventory of pollutantsources may need to be revised by expand-ing the definition of the complaint area orexamining specific locations more closely(e.g., under various operating conditions).

Onsite InspectionDepending upon the nature of the com-plaint, the investigator may find some ofthe following activities to be useful. Thislist is not intended to be complete.

Inventory outdoor sourcesExamine the area around the outdoor airintake for unsanitary conditions, standingwater, or nearby pollutant sources suchas exhaust vents or motor vehicles.Observe patterns of traffic, constructionactivity, and other potential sources inthe neighborhood of the building.

8 7

Inquire about outdoor ambient airproblems in the area. (This informationmay be available from your local HealthDepartment.)Observe soil gas entry points.

Inventory equipment sourcesReview non-HVAC equipment, particu-larly large office equipment such asengineering drawing reproductionmachines and wet-process copiers.Learn about usage patterns and identifyitems that are not equipped with localexhaust.Review biocides and water treatmentsused on HVAC equipment.

Review building components andfurnishings

Check drain traps to make sure they arenot dry.

Identify areas of excessive dust and/ordeteriorated furnishings.Identify areas of soil or water damage.Identify locations of new furnishings.

Inventory other potential sourcesIdentify special use areas such assmoking lounges, laboratories, printshops.Identify areas where remodeling, repair,or redecorating activities are in progressor recently completed. Check proce-dures being used to isolate demolitiondust, paint fumes, and other contami-nants related to the process.Inventory cleaning materials used in thebuilding.

(See Section 4 for another discussion ofproblem indicators and common problemsthat may become obvious during awalkthrough of the building.)

The Pollutant and Source Inventorycan be used to record your observations.The Chemical Inventory form is intendedto serve as a record of materials such assolvents, biocides, pesticides, and cleaningcompounds that may require special care instorage and handling. Material SafetyData Sheets (MSDSs) should be collected

on these materials whenever possible.(See Section 4 for further discussion ofMSDSs.) Portions of both forms areshown on the opposite page; the completeform is included in Tab V.

Talk With Building Occupantsand Facility StaffBuilding occupants and facility staff canprovide valuable information about thelocation and timing of activities thatproduce odors or contaminants (e.g.,smoking, cooking, housekeeping, mainte-nance). They may also suggest explana-tions for the IAQ problem that can help inthe development of hypotheses. Facilitystaff and outside contractors (e.g., personsinvolved in housekeeping, pest control, orremodeling) should be interviewed orasked to provide a current list of materials,procedures, and schedules used forcleaning and pest control.

It may be useful to discuss the followingitems with building occupants:

Inventory activitiesReview smoking policy (and actualpractice; cleaning staff may know wheresmoking occurs in violation of policy,especially in private offices).Identify areas of overcrowding.Review products used for housekeeping,maintenance, and pest control and theschedules of their use.Inquire about housekeeping schedulesand procedures.Identify supply storage areas and checkfor well-sealed containers and properventilation.

Discuss incidents that could be sourcesInquire about prior and neighboring usesof land (e.g., landfills, underground fueltanks).Inquire about events such as spills, fires,or leaks.If such events have occurred, learn whatremedial actions were taken to clean upafter the incidents and to prevent theirrecurrence.

Diagnosing IAQ Problems 738 8

PATrERNS SUGGESTIONS

Location(s)of sources

Compare locations of sources to locations ofcomplaint(s).Identify pathways linking potential sources to thecomplaint area.Revise definition of complaint area ffnecessary.

Timing Note whether the sources emit on a continuousof emissions or intermittent basis.

Compare the timing of emissions to the timingof complaints.Identify occasions when the source is likely to bestrongest.Determine whether pathways between thesource(s) and the complaint location couldaccount for the occasions of complaints.


Use the HypothesisForm on page 223to make brief notesafter reviewing thepollutant sourcedata.Decide whether youhave a hypothesisthat might explainthe complaints. Ifso, test it. (See page78 for a discussionof hypothesistesting.)Decide what elseyou need to know.Consider whether in-house expertise issufficient or outsideassistance is needed.(See Section 8 forguidance on hiringoutside assistance.)

USING POLLUTANT SOURCEDATA

If a strong pollutant source is identified inthe immediate vicinity of the complaint, asimple test (e.g., sealing, covering, orremoving the source) can sometimes revealwhether or not it is the cause of the IAQproblem. If a number of potential sourceshave been found in and around thecomplaint area, other data (e.g., the patternof symptoms, the HVAC system designand operation, and pollutant pathways)may be needed in order to determine whichsource(s), if any, may be related to thecomplaint.

Strategies for Using SourceInformation

Identify patterns linking emissions tocomplaintsEvaluate unrelated sources

Identify Patterns LinkingEmissions to Complaints

Look for patterns linking emissions frompotential sources to the IAQ complaints.

Evaluate Unrelated Sources

Evaluate sources that appear unrelated tothe complaints. It is not unusual to

74 Section 6 89

identify potential contaminant sources thatare unrelated to the present IAQ complaint(i.e., either the location of the source, thetiming of emissions, or both fit poorly withthe pattern of complaints). These shouldbe prioritized for remedial work accordingto their potential for causing healthproblems or complaints in the future.

A detailed study of pollutants andsources may involve an engineeringevaluation of equipment that is releasingIAQ contaminants, diagnostic sampling toassess sources in operation, or othermeasurements. These may require skills orinstruments that are not available in-house.

SAMPLING AIR FORCONTAMINANTS ANDINDICATORS

Although air sampling might seem to bethe logical response to an air qualityproblem, such an approach may not berequired to solve the problem and can evenbe misleading. Air sampling should not beundertaken until some or all of the otherinvestigative activities mentioned previ-ously have been used to collect consider-able information. Before beginning to takeair samples, investigators should develop asampling strategy that is based on acomprehensive understanding of how thebuilding operates, the nature of thecomplaints, and a plan for interpreting theresults.

It may be desirable to take certainroutine air quality measurements during aninvestigation to obtain a "snapshot" ofcurrent conditions. These tests should belimited to those that are indicative of verycommon IAQ concerns such as tempera-ture, relative humidity, air movement, orcarbon dioxide (CO2). Unusual readingsmay or may not indicate a problem, andshould always be interpreted in perspec-tive, based upon site-specific conditions.

Measurement of specific chemical orbiological contaminants can be veryexpensive. Before expending time and

money to obtain measurements of indoorair pollutants, you must decide:

how the results will be used(e.g., comparison to standards orguidelines, comparison to levels incomplaint-free areas)what substances(s) should be measuredwhere to take sampleswhen to take sampleswhat sampling and analysis method touse so that the results provide usefulinformation

It is often worthwhile for building staffto develop skills in making temperature,humidity, airflow, and CO2 measurementsand assessing patterns of air movement(e.g., using chemical smoke). Appendix Aprovides a brief introduction to ventilationand thermal measurement strategies and tomethods of sampling for specific aircontaminants.

How Will the Results Be Used?

Although air sampling will generatenumbers, it will not necessarily helpresolve the IAQ problem. Many IAQcomplaints are resolved without samplingor with inconclusive sampling results.

The design of an air sampling strategyshould fit the intended use of the measure-ments. Potential uses of indoor airmeasurements include:

1. Comparing different areas of the buildingor comparing indoor to outdoor condi-tions in order to:

Confirm that a control approach hasthe desired effect of reducing pollutantconcentrations or improving ventilation

Establish baseline conditions so thatthey can be compared to concentrationsat other times or locations, such as

concentrations in outdoor airconcentrations in areas where nosymptoms are reported

-

expected "background" range fortypical buildings without perceivedIAQ problems

Test a hypothesis about the source ofthe problem, such as

checking emissions from a piece ofequipment

2. Testing for "indicator" compoundsassociated with particular types ofbuilding conditions:

Peak carbon dioxide (CO2) concentra-tions over 1000 ppm (parts per million)are an indicator of underventilation

Carbon monoxide (CO) over severalppm indicates inappropriate presenceof combustion by-products (which mayalso account for high CO2readings)

3. Comparing measured concentrations toguidelines or standards

Occupational exposure standards andguidelines, such as

OSHA PELs (Occupational Safety andHealth Administration's PermissibleExposure Limits)NIOSH RELs (National Institute forOccupational Safety and Health'sRecommended Exposure Limits)ACGIH TLVs (American Conferenceof Governmental Industrial Hygienists'Threshold Limit Values)


Occupants in this one-storyoffice building were com-plaining of intermittentgasoline odors. Exhaustsfrom underground gasolinestorage tank vent pipes(visible in the lower rightportion of this photograph)were being drawn into theoffice building throughoutdoor air intakes on thisroof. The gasoline storagetanks belonged to an adja-cent service station.

It is prudent to begina program of chemicalsampling only ifsymptoms or observa-tions strongly suggestthat a specific pollut-ant or a specificsource may be thecause of the com-plaint and if samplingresults are importantin determining anappropriate correctiveaction.

Public health guidelines for specificpollutants

EPA National Ambient Air QualityStandardsWorld Health Organization AirQuality GuidelinesCanadian Exposure Guidelines forResidential Air Quality

There are no widely accepted proceduresto define whether IAQ test results are ac-ceptable. Extreme caution must be used incomparing contaminant concentrations toexisting occupational standards and guide-lines. Although a contaminant concentra-tion above those guidelines is a clear prob-lem indicator, occupants may still experi-ence health and comfort problems at con-centrations well within those guidelines. Itis extremely rare for occupational stan-dards to, be exceeded or even ap-proached in public and commercialbuildings, including those experiencingindoor air quality problems.

Where specific exposure problems aresuspected, more detailed diagnostic testingmay be needed to locate or understandmajor sources, confirm the exposure, andto develop appropriate remedial actions.For example, the control of microbial orpesticide contamination may involve sur-face or bulk sampling. (Surface samplinginvolves wiping a measured surface areaand analyzing the swab to see what organ-isms are present, while bulk samplinginvolves analyzing a sample of suspectmaterial.) Specialized skills, experience,and equipment may be needed to obtain,analyze, and interpret such measurements.

What Substance(s) Should BeMeasured?

Measurement of "indicator" compoundssuch as CO2 or CO can be a cost-effectivestrategy. Such measurements can help theinvestigator understand the nature of theproblem and define the complaint area.

76 Section 6

Air sampling for specific pollutantsworks best as an investigative tool when itis combined with other types of informa-tion-gathering. It is prudent to begin aprogram of chemical sampling only ifsymptoms or observations strongly suggestthat a specific pollutant or a specific sourcemay be the cause of the complaint and ifsampling results are important in determin-ing an appropriate corrective action.

Where Should Air Samples BeTaken?

The identified problem area is an obvioussite for air sampling. Measurements takenoutdoors and in a control location (e.g., acomplaint-free area of the building) arehelpful in interpreting results from thecomplaint area.

The conditions experienced by buildingoccupants are best simulated by samplingair from the "breathing zone" away fromthe influence of any particular individual.However, if an individual sits at a desk allday (except for brief periods), samplersplaced on the desk when the individual iselsewhere can provide a good estimate ofthat person's exposure.

There are several ways to locate sam-pling sites for an IAQ investigation. Oneapproach first divides the building intohomogeneous areas based on key factorsidentified in the building inspection andinterviews. Examples of how a buildingmight be divided include:

control zones (e.g., individual rooms)types of HVAC zones (e.g., interior vs.perimeter)complaint vs. non-complaint areasrelationship to major sources(e.g., spaces directly, indirectly, or notimpacted by smoking areas)complaint types

Test sites can then be selected to repre-sent complaints, controls, and potentialsources with a reasonable number ofsamples.

When Should Air Samples BeTaken?

Samples may be designed to obtain "worst-case" conditions, such as measurementsduring periods of maximum equipmentemissions, minimum ventilation, or distur-bance of contaminated surfaces. Worst-case sample results can be very helpful incharacterizing maximum concentrations towhich occupants are exposed and identify-ing sources for corrective measures.

It is also helpful to obtain samples duringaverage or typical conditions as a basis ofcomparison. It may, however, be difficultto know what conditions are typical. Re-search shows that exposure to some pollut-ants may vary dramatically as buildingconditions change. Devices that allowcontinuous measurements of key variablescan be helpful.

Symptoms or odors that only occur occa-sionally will not generally be seen duringthe IAQ investigation. Air samples shouldnot be taken if an incident is not occurring,unless the purpose of the sample is to es-tablish a baseline for future comparisons.

One approach to intermittent IAQ prob-lems is for the IAQ investigator to askappropriate building staff or other occu-pants to document changes over time usingday-to-day records such as the OccupantDiary and Log of Activities and SystemOperation. When an odor episode doesoccur, the building engineer could inspectthe air handler and intake area while an-other staff member documents the status ofseveral potential sources.

Another strategy is to manipulatebuilding conditions to create worst-caseconditions during the building investiga-tion (e.g., arrange for the trash truck to idleat the loading dock or close outdoor airdampers to minimum settings). Chemicalsmoke and tracer gases can be used toassess where emissions may travel undervarious building conditions. (Suchstrategies should be carried out in waysthat minimize occupant exposure.)

What Sampling and AnalysisMethod Should Be Used?

Take care to select appropriate measure-ment techniques and to provide interpret-ations so that the results provide usefulinformation. Appendix A providesguidance on measurement techniques thatare commonly used in IAQ investigations.

COMPLAINTS DUE TOCONDITIONS OTHER THANPOOR AIR QUALITY

Complaints that initially seem to be linkedto thermal discomfort, underventilation, orindoor air pollutants may actually becaused or complicated by factors such as:

environmental stressors (e.g., lighting,noise, vibration)ergonomic stressorsjob-related psychosocial (human rela-tions) stressors

The following briefly discusses each ofthese three kinds of stressors. Investiga-tors should bear in mind that complaintsproduced by these stressors are sometimesmistakenly blamed on contaminated air.To complicate matters, such stressors alsocan produce a heightened sensitivity topoor indoor air quality. Thus, even whenspecific stressors are obvious, the investi-gator should not assume that they are theonly reason for the complaints.

Lighting

Stresses from inadequate or poorlydesigned lighting (e.g., glare, flicker, poorillumination of work surfaces) can producesymptoms such as eyestrain and head-aches. Lack of natural sunlight can also bea source of stress. These complaints aresometimes mistakenly interpreted as signsof poor indoor air quality. Lightingproblems may be evident in large areas orlocalized in particular workspaces.

42Diagnosing IAQ Problems

Investigators shouldbear in mind thatcomplaints producedby these stressors aresometimes mistakenlyblamed on contami-nated air. To compli-cate matters, suchstressors also canproduce a heightenedsensitivity to poorindoor air quality.

The glare from the windowswas causing a variety ofoccupant complaints in thisbuilding and was disruptingthe workers' ability to usethe video display terminals.Complaints such asheadaches are sometimesincorrectly blamed on poorindoor air quality.

Noise

Noisy surroundings can reduce the abilityto concentrate and produce stress-relatedsymptoms such as headaches. Noise canalso contribute to job dissatisfaction,particularly if the problem is caused byovercrowding or other factors likely toproduce a sense of substandard workconditions.

The ear gets used to sounds quickly, so itis possible for a complainant to be unawareof a constant or regular sound. Investiga-tors should recognize that noise can be asource of stress, even if it is not reported asa problem and is within current industrialexposure criteria (which are designedprimarily to prevent hearing loss).

Vibration

Low-frequency vibration is another sourceof stress that may go unreported bybuilding occupants or become confusedwith pollutant problems. Vibration can becaused by nearby machinery or movementof the building as a whole; motion sicknesshas been reported in some high risebuildings that sway in the wind.

78 Section 6

Ergonomic Stressors

Fatigue, circulatory problems, and otherphysical problems can be produced byfurniture that is mismatched to the task,such as chairs that are the wrong height forcomputer terminals. If IAQ investigatorsinquire about whether new furniture hasrecently been installed in the problem area(to determine if the furniture could becontributing to increased contaminantlevels), they should also ask aboutwhether the occupant finds the furniturecomfortable.

Job-related PsychosocialStressors

It is well documented that various job-related psychosocial conditions canproduce symptoms in workers. Excessiveworkload and work pressure are easilyrecognized job stressors. Lack of clarityabout what is expected of the worker (roleambiguity) and the presence of conflictingexpectations (role conflict) are alsocommonly encountered stressors inmodern organizations. Poor interpersonalrelations, management styles that allowlittle participation in decision-making, andfactors related to career development arealso thought to be potentially stressful.

FORMING AND TESTINGHYPOTHESES

As the building investigation progresses,you should be developing one or morehypotheses that could explain the occupantcomplaints. The investigation can then beshaped to collect information that willeither support or refute your hypotheses.

The Hypothesis Form on the oppositepage is designed to pull together theseparate pieces of information that havebeen collected by summarizing the resultsof the investigation. More pages can beadded if desired, but the form is designedfor brief notes that can be scanned easily.As you review the information, write down

9 3

any explanation(s) of the IAQ problem thatmake sense, and think about how thepieces of the puzzle fit together whenbuilding conditions are compared tooccupant complaints.

Is all (or most) of your informationconsistent with your hypothesis? If not, isthere a reasonable explanation for theinconsistencies? A different hypothesismight provide a better fit with yourinformation.

You may find that there are several IAQproblems (e.g., underventilation in onezone, a strong contaminant source inanother room). If you have discoveredpotential IAQ problems that do not appearrelated to the original complaint, they canbe prioritized and corrected as time andfunding permit.

Think of ways to test your hypotheses.You may want to change ventilation rates,change the pressure relationship betweenspaces, cover or remove suspected sources,seal pathways, or temporarily relocateaffected individuals. If your manipulationscan reduce occupant complaints, you havefound a reasonable hypothesis. Sometimesit is not possible (or not practical) tomanipulate important factors. You canalso test your hypothesis by seeing howaccurately you can predict changes inbuilding conditions (e.g., as outdoortemperature changes).

If you are having difficulty developinghypotheses, review the information youhave collected and the suggestions abouthow to use that information. For sugges-tions on using occupant complaint data,see pages 53-57; on using HVAC systeminformation, see pages 62-67; on usingpollutant pathway information, see pages70-71; on using pollutant/source inventorydata, see page 74; on using air samplinginformation, see pages 75-76.

The changes that arc made duringhypothesis testing may offer a practicalsolution to the IAQ problem, or may beonly temporary measures. The mitigationchapter presents a variety of approachesthat have been used in correcting someselected categories of IAQ problems anddiscusses how to evaluate those strategies.

seeemeSEECOMPLETEFORMPAGE 223

Sample FormHypothesis Form

Complaint Area (may be revised as the investigation progresses):

Complaints (e.g., summarize patterns of timing, location, peopleaffected):

HVAC: Does the ventilation system appear to provide adequateair, efficiently distributed to meet occupant needs in the complaintarea? If not, what problems do you see?

Pathways: What pathways and driving forces connect thecomplaint area to locations of potential sources?


Mitigating IACI Problems

Over the years many types of mitigation(correction) strategies have been imple-mented to solve indoor air quality prob-lems. The purpose of this section is toprovide an understanding of basic ap-proaches to mitigation and the varioussolutions that can be effective in treatingcommonly encountered IAQ problems. Itis not intended to provide detailed instruc-tions for using each type of mitigationapproach but rather to give guidance inselecting a mitigation strategy and injudging proposals from in-house staff oroutside consultants.

Mitigation of indoor air quality prob-lems may require the involvement ofbuilding management and staff represent-ing such areas of responsibility as:

facility operation and maintenancehousekeepingshipping and receivingpurchasingpolicymakingstaff training

Successful mitigation of IAQ problemsalso requires the cooperation of otherbuilding occupants, including the employ-ees of building tenants. Occupants must beeducated about the cause(s) of the IAQproblems and about actions that must betaken or avoided to prevent a recurrence ofthe problems.

BACKGROUND: CONTROLLINGINDOOR AIR PROBLEMS

Section 2 introduced the idea that indoorair quality problems result from interac-tions between contaminant source,building site, building structure, activitieswithin the building, mechanical equipment,climate, and occupants. Efforts to control

indoor air contaminants change therelationships between these factors. Thereare many ways that people can intervene inthese relationships to prevent or controlindoor air contaminant problems. Controlstrategies can be categorized as:

source controlventilationair cleaningexposure control

Successful mitigation often involves acombination of these strategies. Possibleremedies for the other environmentalstressors discussed in Section 6 arediscussed briefly below.

Source Control

All efforts to prevent or correct IAQproblems should include an effort toidentify and control pollutant sources.Source control is generally the most costeffective approach to mitigating IAQproblems in which point sources ofcontaminants can be identified. In the caseof a strong source, source control may bethe only solution that will work.

The following are categories andexamples of source control:

Remove or reduce the sourceprohibit smoking indoors or limitsmoking to areas from which air isexhausted, not recirculated (NIOSHregards smoking areas as an interimsolution)relocate contaminant-producing equip-ment to an unoccupied, better ventilated,or exhaust-only ventilated spaceselect products which produce fewer orless potent contaminants while maintain-ing adequate safety and efficacy

Mitigating IAQ Problems 81

PT

modify other occupant activities

Seal or cover the sourceimprove storage of materials thatproduce contaminantsseal surfaces of building materials thatemit VOCs such as formaldehyde

Modify the environmentafter cleaning and disinfecting an areathat is contaminated by fungal orbacterial growth, control humidity tomake conditions inhospitable forregrowth

Source removal or reduction cansometimes be accomplished by a one-timeeffort such as thorough cleaning of a spill.In other cases, it requires an ongoingprocess, such as establishing and enforcinga non-smoking policy.

Sealing or covering the source can be asolution in some cases; application of abarrier over formaldehyde-emittingbuilding materials is an example. Sealingmay also involve educating staff orbuilding occupants about the contaminant-producing features of materials andsupplies and inspecting storage areas toensure that containers are properlycovered.

In some cases, modification of theenvironment is necessary for effectivemitigation. If the indoor air problemarises from microbiologi61 contaminants,for example, disinfection of the affectedarea may not eliminate the problem.Regrowth of microbiologicals couldoccur unless humidity control or othersteps, such as adding insulation to preventsurface condensation, are taken to makethe environment inhospitable to micro-biologicals.

Ventilation

Ventilation modification is often used tocorrect or prevent indoor air qualityproblems. This approach can be effectiveeither where buildings are underventilatedor where a specific contaminant source

82 Section7

cannot be identified. Ventilation can beused to control indoor air contaminants by:

Diluting contaminants with outdoor airincrease the total quantity of supply air(including outdoor air)increase the proportion of outdoor air tototal airimprove air distribution

Isolating or removing contaminants bycontrolling air pressure relationships

install effective local exhaust at thelocation of the sourceavoid recirculation of air that containscontaminantslocate occupants near supply diffusersand sources near exhaust registersuse air-tightening techniques to maintainpressure differentials and eliminatepollutant pathwaysmake sure that doors are closed wherenecessary to separate zones

Diluting contaminants by increasingthe flow of outdoor air can be accom-plished by increasing the total supplyairflow in the complaint area (e.g., openingsupply diffusers, adjusting dampers) or atthe air handling unit, (e.g., cleaning thefilter on the supply fan). An alternative isto increase the proportion of outdoor air(e.g., adjusting the outdoor air intakedamper, installing minimum stops onvariable air volume (VAV) boxes so thatthey satisfy the outdoor air requirements ofASHRAE 62-1989).

Studies have shown that increasingventilation rates to meet ASHRAEStandard 62-1989 (e.g., from 5 to 15 or 20cfm/person) does not necessarily signifi-cantly increase the total annual energyconsumption. The increase appears to beless than 5% in typical commercialbuildings. The cost of ventilation isgenerally overshadowed by other operatingcosts, such as lighting. Further, improvedmaintenance can produce energy savingsto balance the costs that might otherwiseresult from increased ventilation.

96

The cost of modifying an existingHVAC system to condition additionaloutdoor air can vary widely dependingupon the specific situation. In somebuildings, HVAC equipment may not havesufficient capacity to allow successfulmitigation using this approach. Originalequipment is often oversized so that it canbe adjusted to handle the increased load,but in some cases additional capacity isrequired.

Most ventilation deficiencies appear tobe linked to inadequate quantities ofoutdoor thr. However, inadequate distribu-tion of ventilation air can also produceIAQ problems. Diffusers should beproperly selected, located, installed, andmaintained so that supply air is evenlydistributed and blends thoroughly withroom air in the breathing zone. Short-circuiting occurs when clean supply air isdrawn into the return air plenum before ithas mixed with the dirtier room air andtherefore fails to dilute contaminants.Mixing problems can be aggravated bytemperature stratification. Stratificationcan occur, for example, in a space withhigh ceilings in which ceiling-mountedsupply diffusers distribute heated air.

Note the side effects of increasedventilation:

mitigation by increasing the circulationof outdoor air requires good outdoor airqualityincreased supply air at the problemlocation might mean less supply air inother areasincreased total air in the system andincreased outdoor air will both tend toincrease energy consumption and mayrequire increased equipment capacityany approach which affects airflow in thebuilding can change pressure differencesbetween rooms (or zones) and betweenindoors and outdoors, and might lead toincreased infiltration of unconditionedoutdoor airincreasing air in a VAV system mayovercool an area to the extent thatterminal reheat units are needed

Ventilation equipment can be used toisolate or remove contaminants bycontrolling pressure relationships. If thecontaminant source has been identified,this strategy can be more effective thandilution. Techniques for controlling airpressure relationships range from adjust-ment of dampers to installation of localexhaust.

Using local exhaust confines the spreadof contaminants by capturing them near thesource and exhausting them to the out-doors. It also dilutes the contaminant bydrawing cleaner air from surrounding areasinto the exhaust airstream. If there arereturn grilles in a room equipped with localexhaust, the local exhaust should exertenough suction to prevent recirculation ofcontaminants. Properly designed andinstalled local exhaust results in far lowercontaminant levels in the building thancould be accomplished by a generalincrease in dilution ventilation, with theadded benefit of costing less.

Note that replacement air must be ableto flow freely into the area from which theexhaust air is being drawn. It may benecessary to add door or wall louvers inorder to provide a path for the make-up air.(Make sure that this action does not violatefire codes.)

Correct identification of the pollutantsource and installation of the local exhaustis critically important. For example, animproperly designed local exhaust candraw other contaminants through theoccupied space and make the problemworse.

The physical layout of grilles anddiffusers relative to room occupants andpollutant sources can be important. Ifsupply diffusers are all at one end of aroom and returns are all at the other end,the people located near the supplies maybe provided with relatively clean air whilethose located near the returns breathe airthat has already picked up contaminantsfrom all the sources in the room that arenot served by local exhaust.

Mitigating IAQ Problems 83 97

Elimination of pollutant pathways by airsealing (e.g., caulking cracks, closingholes) is an approach that can increase theeffectiveness of other control techniques.It can be a difficult technique to implementbecause of hidden pathways (e.g., abovedrop ceilings, under raised flooring,against brick or block walls). However, itcan have other benefits such as energysavings and more effective pest control (byeliminating paths used by vermin).

Air Cleaning

The third IAQ control strategy is to cleanthe air. Air cleaning is usually most effec-tive when used in conjunction with eithersource control or ventilation; however, itmay be the only approach when the sourceof pollution is outside of the building.Most air cleaning in large buildings isaimed primarily at preventing contaminantbuildup in HVAC equipment and enhanc-ing equipment efficiency.

Air cleaning equipment intended toprovide better indoor air quality for occu-pants must be properly selected and de-signed for the particular pollutants of inter-est (for example, gaseous contaminants canbe removed only by gas sorption). Onceinstalled, the equipment requires regularmaintenance in order to ensure good per-formance; otherwise it may become amajor pollutant source in itself. This main-tenance requirement should be borne inmind if an air cleaning system involving alarge number of units is under consider-ation for a large building. If room units areused, the installation should be designedfor proper air recirculation.

There are four technologies that removecontaminants from the air:

particulate filtrationelectrostatic precipitationnegative ion generationgas sorption

84 Section 7

The first three approaches are designedto remove particulates, while the fourth isdesigned to remove gases.

Particulate filtration removes sus-pended liquid or solid materials whosesize, shape and mass allow them to remainairborne at the air velocity conditionspresent. Filters are available in a range ofefficiencies, with higher efficiency indicat-ing removal ofa greater proportion ofparticles and of smaller particles. Movingto medium efficiency pleated filters isadvisable to improve IAQ and increaseprotection for equipment. However, thehigher the efficiency of the filter, the moreit will increase the pressure drop within theair distribution system and reduce totalairflow (unless other adjustments are madeto compensate). It is important to select anappropriate filter for the specificapplication and to make sure that theHVAC system will continue to perform asdesigned. Filters are rated by differentstandards (e.g., arrestance and dust spot)which measure different aspects ofperformance.

Electrostatic precipitation is anothertype of particulate control. It uses theattraction of charged particles to oppositelycharged surfaces to collect airborne par-ticulates. In this process, the particles arecharged by ionizing the air with an electricfield. The charged particles are then col-lected by a strong electric field generatedbetween oppositely-charged electrodes.This provides relatively high efficiencyfiltration of small respirable particles atlow air pressure losses.

Electrostatic precipitators may be in-stalled in air distribution equipment or inspecific usage areas. As with other filters,they must be serviced regularly. Note,however, that electrostatic precipitatorsproduce some ozone. Because ozone isharmful at elevated levels, EPA has setstandards for ozone concentrations in out-door air, and NIOSH and OSHA have

98

established guidelines and standards, re-spectively, for ozone in indoor air. Theamount of ozone emitted from electrostaticprecipitators varies from model to model.

Negative ion generators use staticcharges to remove particles from the indoorair. When the particles become charged,they are attracted to surfaces such as walls,floors, table tops, draperies, and occupants.Some designs include collectors to attractthe charged particles back to the unit.Negative ion generators ard not availablefor installation in ductwork, but are sold asportable or ceiling-mounted units. As withelectrostatic precipitators, negative iongenerators may produce ozone, either inten-tionally or as a by-product of use.

Gas sorption is used to control com-pounds that behave as gases rather than asparticles (e.g., gaseous contaminants suchas formaldehyde, sulfur dioxide, ozone, andoxides of nitrogen). Gas sorption involvesone or more of the following processeswith the sorption material (e.g., activatedcarbon, chemically treated active clays): achemical reaction between the pollutantand the sorbent; a binding of the pollutantand the sorbent; or diffusion of the con-taminant from areas of higher concentrationto areas of lower concentration. Gas sorp-tion units are installed as part of the airdistribution system. Each type of sorptionmaterial performs differently with differentgases. Gas sorption is not effective forremoving carbon monoxide. There are nostandards for rating the performance ofgaseous air cleaners, making the design andevaluation of such systems problematic.Operating expenses of these units can bequite high, and the units may not be effec-tive if there is a strong source nearby.

Exposure Control

Exposure control is an administrative ap-proach to mitigation that uses behavioralmethods, such as:

Scheduling contaminant-producing activi-ties to avoid complaints

schedule contaminant-producing activi-ties to occur during unoccupied periodsnotify susceptible individuals about up-coming events (e.g., roofmg, pesticideapplication) so that they can avoid contactwith the contaminants

Scheduling contaminant-producing ac-tivities for unoccupied periods wheneverpossible is simple common sense. It maybe the best way to limit complaints aboutactivities (such as roofing or demolition)which unavoidably produce odors or dust.

Relocating susceptible individualsmove susceptible individuals away fromthe area where they experience symptoms

Controlling exposure by relocating sus-ceptible individuals may be the only practi-cal approach in a limited number of cases,but it is probably the least desirable optionand should be used only when all otherstrategies are ineffective in resolving com-plaints.

Remedies for Complaints NotAttributed to Poor Air Quality

Specific lighting deficiencies or localizedsources of noise or vibration can sometimesbe readily identified, and remedial actionmay be fairly straightforward (more orfewer lights on, adjustments for glare; relo-cating, replacing or acoustically insulating anoise or vibration source). Similarly, fla-grant ergonomic stress or blatantpsychosocial stress may be apparent even toan untrained observer.

In other cases, however, problems maybe more subtle or solutions more complex.Since specialized knowledge, skills, andinstrumentation are usually needed toevaluate lighting, noise, vibration, ergo-nomic stress, or psychosocial stress, suchevaluations are generally best done by aqualified professional in that particularfield.


Remedial actions for lighting, noise,and vibration problems might range frommodifications of equipment or furnishingsto renovation of the building. Ergonomicdeficiencies may require furniture orequipment changes or different workpractices. The solution to psychosocialproblems may involve new managementpractices, job redesign, or resolution ofunderlying labor-management problems.

SAMPLE PROBLEMS ANDSOLUTIONS

In the investigation section you wereintroduced to a variety of problems that areoften found in buildings. This sectionpresents fifteen categories of IAQ prob-lems. Specific problem "examples" aregiven, followed by "solutions" that havebeen used for that category of problem.Most of the problems presented here arecommon and do not have serious, life-threatening consequences. At the end ofthe section is a brief description ofproblems that can have severe healthimpacts. The basic correction principlesthat apply to these serious problems aresimilar to those used in less criticalsituations.

Reading these examples may help youthink about the best way to solve yourindoor air quality problems. Rememberthat these are brief sketches, and apparentparallels to your building could be mis-leading. It is better to carry out a buildinginvestigation and learn the specific facts inyour own case, rather than adopt a mitiga-tion approach that might not be appropri-ate. Attempting to correct IAQ problemswithout understanding the cause of thoseproblems can be both ineffective andexpensive.

10086 Section 7

You will note that some solutions aresimple and low-cost, while others arecomplex and expensive. Do not assumethat each solution listed would be aneffective treatment for all of the problemsin its category.

The example problems and solutiOns arepresented in the following sequence:

Problem #1: Outdoor air ventilation rate'is too low

Problem #2: Overall ventilation rate ishigh enough, but poorlydistributed and not sufficientin some areas

Problem #.1: Contartinant enters buildingfrom outdoors

Problem #4: Occupant activities contrib-ute to air contaminants or tocomfort problems

Problem #5: HVAC system is a source ofbiological contaminants

Problem #6: HVAC system distributescontaminants

Problem #7: Non-HVAC equipment is asource or distribution mecha-nism for contaminants

Problem #8: Surface contamination due topoor sanitation or accidents

Problem #9: Mold and mildew growthdue to moisture from con-densation

Problem #10: Building materials and

furnishings produce

contaminants

Problem #11: Housekeeping or mainte-nance activities contribute toproblems

Problem #12: Specialized use areas assources of contaminants

Problem #13: Remodeling or repair activi-ties produce problems

Problem #14: Combustion gases

Problem #15: Serious building-relatedillness

Problem #1:Outdoor Air VentilationRate is Too Low

Examples

Routine odors from occupants andnormal office activities result in problems(e.g., drowsiness, headaches, discomfort)

Measured outdoor air ventilation rates donot meet guidelines for outdoor air supply(e.g., design specifications, applicablecodes, or ASHRAE 62-1989)

Peak CO2 concentrations above 1000ppm indicate inadequate ventilation

Corrosion of fan casing causes airbypassing and reduces Willow in system

Solutions

Open, adjust or repair air distributionsystem

outdoor air intakesmixing and relief damperssupply diffusersfan casings

Increase outdoor air within the designcapacity of

air handlerheating and air conditioning equipmentdistribution system

Modify components of the HVAC systemas needed to allow increased outdoor air

(e.g., increase capacity of heating andcooling coils)

Design and install an updated ventilationsystem

Reduce the pollutant andlor thermal loadon the HVAC system

reduce the occupant density: relocatesome occupants to other spaces toredistribute the load on the ventilationsystemrelocate or reduce usage of heat-generating equipment

***!i,.1.1

Malfunctioning controls such as thisbroken damper linkage can virtuallyeliminate intake of outdoor air. Suchproblems may go undetected for yearswithout a careful investigation of theHVAC system components.

101


Problem #2:Overall Ventilation Rate IsHigh Enough, But PoorlyDistributed and NotSufficient in Some Areas

Complaining of discomfort, buildingoccupants blocked air supply diffusers intheir work areas. The HVAC system inthis building was in poor condition andwas not balanced.

88 Section7

Examples

Measured outdoor air meets guidelines atbuilding air inlet, but there are zoneswhere heat, routine odors from occu-pants, and normal office activities resultin complaints(e.g., drowsiness, headaches, comfortcomplaints)

Solutions

Open, adjust, or repair air distributionsystem

supply diffusersreturn registers

Ensure proper air distribution

balance the air handling systemmake sure that there is an air gap at topsand bottoms of partitions to prevent deadair spacerelocate supply and/or return diffusers toimprove air distribution

Seal leaky ductwork

Remove obstructions from return airplenum

Control pressure relationships

install local exhaust in problem areasand adjust HVAC system to provideadequate make-up airmove occupants so that they are closer tosupply diffusersrelocate identified contaminant sourcescloser to exhaust intakes

Reduce source by limiting activities orequipment use that produce heat, odors,or contaminants

Design and install an appropriate'ventilation system

102

Problem #3:Contaminant Enters BuildingFrom Outdoors

Examples

Soil gases(e.g., radon, gasoline from tanks, methanefrom landfills)

Contaminants from nearby activities(e.g., roofing, dumpster, construction)

Outdoor air intake near source(e.g., parking, loading dock, buildingexhaust)

Outdoor air contains pollutants or excessmoisture(e.g., cooling tower mist entrained inoutdoor air intake)

Solutions

Remove the source (if it can be movedeasily)

remove debris around outdoor air intakerelocate dumpster

Reduce source (for example, shift time ofactivity to avoid occupied periods)

painting, roofing, demolitionhousekeeping, pest control

Relocate elements of the ventilationsystem that contribute to entry of outdoorair contaminants

separate outdoor air intakes from sourcesof odors, contaminantsseparate exhaust fan outlets fromoperable windows, doors, air intakesmake rooftop exhaust outlets taller thanintakes

Change air pressure relationships tocontrol pollutant pathways

install subslab depressurization toprevent entry of soil gas contaminants(radon, gases from landfills and under-ground tanks)pressurize the building interior relative tooutdoors (this will not prevent contami-nant entry at outdoor air intakes)close pollutant pathways (e.g., sealcracks and holes)

Add special equipment to HVAC system

filtration equipment to remove pollutants(select to fit the situation)

103


For cosmetic reasons, airintakes are frequentlylocated on rooftops or nearthe ground. This air intakecould become a means ofdrawing lawn cuttings,vehicle exhaust, andpesticides into the building.

Problem #4:Occupant ActivitiesContribute to AirContaminants or toComfort Problems

11404,

,

_J

Personal equipment such as humidifiersbrought in by building occupants canbecome a source of contaminants if notproperly maintained. An effectivecommunication strategy can helpoccupants to understand their role incausing indoor air quality problems andin correcting those problems.

90 Section 7

104

Examples

Smoking

Special activities such as print shops,laboratories, kitchens

Interference with HVAC systemoperation:

blockage of supply diffusers to eliminatedraftsturning off exhaust fans to eliminatenoiseuse of space heaters, desktop humidifiersto remedy local discomfort.

(Note: While such interference can causeIAQ problems, it is often initiated inresponse to unresolved ventilation ortemperature control problems.)

Solutions

Remove the source by eliminating theactivity(Note: This may require a combination ofpolicy-setting and educational outreach.)

smokinguse of desktop humidifiers and otherpersonal HVAC equipmentunsupervised manipulation of HVACsystem

Reduce the sourceselect materials and processes whichminimize release of contaminants whilemaintaining adequate safety and efficacy(e.g., solvents, art materials)

Install new or improved local exhaust toaccommodate the activity, adjust HVACsystem to ensure adequate make-up air,and verify effectiveness

smoking lounge, storage areas whichcontain contaminant sourceslaboratory hoods, kitchen range hoods(venting to outdoors, not recirculating)

Problem #5:HVAC System is a Source ofBiological ContaminantsThe HVAC system can act as a source ofcontaminants by providing a hospitableenvironment for the growth of microorgan-isms and then distributing biologically-contaminated air within the building.

Examples

Surface contamination by molds (fungi),bacteria

drain pansinterior of ductworkair filters and filter media (collecteddebris).

Solutions

Remove source by improving mainte-nance procedures

inspect equipment for signs of corrosion,high humidityreplace corroded partsclean drip pans, outdoor air intakes,other affected locationsuse biocides, disinfectants, and sanitizerswith extreme caution and ensure thatoccupant exposure is minimized

(Note: See discussion of duct cleaning inAppendix B.)

Provide access to all the items thatmust be cleaned, drained, or replacedperiodically

_AgriMILLJoiMMIM.

-

This blackish deposit was scraped froma poorly maintained air handling unitdrain pan. The pan contained nutrientscaused by poor upstream filtration andstagnant water that fostered the growthof microbiological contaminants.

105


Problem #6:HVAC System DistributesContaminants

Standing water on a roof can causewater damage and potential moldgrowth sites inside the building as wellas providing a breeding area for insectsand microbiologicals such as Legionella.The outside air intake (near the far left ofthis photograph) is located close to thestanding water and could be drawing ininsects and microbiologicalcontaminants.,

92 Section 7

Examples

Unfiltered air bypasses filters due toproblems

filter tracks are loosepoorly maintained filters sag when theybecome overloaded with dirtfilters are the wrong size

Recirculation of air that contains dust orother contaminants

system recirculates air from roomscontaining pollutant sourcesreturn air plenum draws air from roomsthat should be exhausted (e.g., janitor'sclosets)

return air plenums draw soil gases frominteriors of block corridor walls thatterminate above ceilings

Solutions

Modify air distribution system tominimize recirculation of contaminants

provide local exhaust at point sources ofcontaminants, adjust HVAC system toprovide adequate make-up air, and test toverify performanceincrease proportion of outdoor airseal unplanned openings into return airplenums and provide alternative localventilation (adjust HVAC system toprovide adequate make-up air and test toverify performance)

Improve housekeeping, pest control,occupant activities, and equipment use tominimize release of contaminants fromall sources

Install improved filtration equipment toremove contaminants

Check filter tracks for any gaps

100

Problem #7:Non-HVAC Equipment isa Source or DistributionMechanism for Contaminants

This discussion pertains to medium- tolarge-scale pieces of equipment.

Examples

Non-HVAC equipment can producecontaminants, as in the case of:

wet process copierslarge dry process copiersengineering drawing reproductionmachines

It can also distribute contaminants, as inthe case of:

elevators, which can act as pistons anddraw contaminants from one floor toanother

Solutions

Install local exhaust near machines(Note: Adjust HVAC system to provideadequate make-up air, and test to verifyperformance.)

Reschedule use to occur during periods oflow occupancy

Remove source

relocate occupants out of roomsthat contain contaminant-generatingequipmentrelocate equipment into special useareas equipped with effective exhaustventilation (test to verify control of airpressure relationships)

Change air pressure relationships toprevent contaminants from enteringelevator shaft

Sometimes there are unusual sources ofindoor air quality problems. Aninspection of the HVAC system revealedair filters covered with a graphite dustdeposit from a broken elevator motorgenerator. The motor generator wasrepaired and corrections were made toprevent the crossover of ventilation airfrom the motor generator into the HVACmechanical room.


Problem #8:Surface ContaminationDue to Poor Sanitation orAccidents

The carpet on this floor was floodedand an outbreak of humidifier feveroccurred. To eliminate microbiologicals,the contaminated carpet was removedand new carpet was installed.

10394 Section 7

Examples

Biological contaminants result in aller-gies or other diseases

fungal, viral, bacterial (whole organismsor spores)bird, insect, or rodent parts or droppings,hair, dander (in HVAC, crawlspace,building shell, or near outdoor airintakes)

Accidents

spills of water, beverages, cleansers,paints, varnishes, mastics or specializedproducts (printing, chemical art supplies)fire damage: soot, odors, chemicals

Solutions

Clean

HVAC system componentssome materials and furnishings (othersmay have to be discarded)

(Note: Use biocides, disinfectants, andsanitizers with caution and ensure thatoccupant exposure is minimized.)

Remove sources of microbiologicalcontamination

water-damaged carpet, furnishings, orbuilding materials

Modify environment to prevent recur-rence of microbiological growth

improve HVAC system maintenancecontrol humidity or surface temperaturesto prevent condensation

Provide access to all items that requireperiodic maintenance

Use local exhaust where corrosivematerials are stored

Adjust HVAC system to provide adequatemake-up air, and test to verify perfor-mance

Problem #9:Mold and Mildew GrowthDue to Moisture fromCondensation

Examples

Interior surfaces of walls near thermalbridges(e.g., uninsulated locations around struc-tural members)

Carpeting on cold floors

Locations where high surface humiditypromotes condensation

Solutions:

Clean and disinfect to remove mold andmildew(Note: Follow up by taking actions toprevent recurrence of microbiologicalcontamination. Use biocides, disinfec-tants, and sanitizers with caution andensure that occupant exposure is mini-mized.)

Increase surface temperatures to treatlocations that are subject to condensation

insulate thermal bridgesimprove air distribution

Reduce moisture levels in locations thatare subject to condensation

repair leaksincrease ventilation (in cases whereoutdoor air is cold and dry)dehumidify (in cases where outdoor airis warm and humid)

Dry carpet or other textiles promptly aftersteam cleaning(Note: Increase ventilation to acceleratedrying.)

Discard contaminated materials

^r ,

This is a school crawlspace in whichmoisture should be controlled. Thefungus is Fusarium, some species ofwhich are toxigenic and should not beinside. The spores were distributed bythe air handler because the returnplenum was open to the crawlspace.

109


Problem #10:Building Materials andFurnishings ProduceContaminants

Low levels of contaminants are emittedfrom many of the building materialsand furnishings in an office. Dust canaccumulate on stacks of papers andopen shelves. Depending on howthey are cared for, plants potentiallyadd moisture, soil microbiologicals,and pesticides.

110

96 Section7

Examples

Odors from newly installed carpets,furniture, wall coverings

Newly drycleaned drapes or other textiles

Solutions

Remove source with appropriate cleaningmethods

steam clean carpeting and upholstery,then dry quickly, ventilating to acceler-ate the drying processaccept only fully dried, odorlessdrycleaned products

Encapsulate source

seal surfaces of building materials thatemit formaldehyde

Reduce source

schedule installation of carpet, furniture,and wall coverings to occur duringperiods when the building is unoccupiedhave supplier store new furnishings in aclean, dry, well-ventilated area untilVOC outgassing has diminished

Increase outdoor air ventilation

total air suppliedproportion of fresh air

Remove the materials that are producingthe emissions and replace with loweremission alternatives(Note: Only limited information onemissions from materials is available atthis time. Purchasers can request thatsuppliers provide emissions test data, butshould use caution in interpreting the testresults.)

Problem # 1 1Housekeeping or MaintenanceActivities Contribute toProblems

Examples

Cleaning products emit chemicals, odors

Particulates become airborne duringcleaning (e.g., sweeping, vacuuming)

Contaminants are released from painting,caulking, lubricating

Frequency of maintenance is insufficientto eliminate contaminants

Solutions

Remove source by modifying standardprocedures or frequency of maintenance(Note: Changing procedures may require acombination of policy-setting and trainingin IAQ impacts of staff activities.)

improve storage practicesshift time of painting, cleaning, pestcontrol, other contaminant-producingactivities to avoid occupied periodsmake maintenance easier by improvingaccess to filters, coils, and other compo-nents

Reduce source

select materials to minimize emissions ofcontaminants while maintaining ad-equate safety and efficacyuse portable HEPA ("high efficiencyparticulate arrestance") vacuums vs. low-efficiency paper-bag collectors

Use local exhaust

on a temporary basis to remove contami-nants from work areasas a permanent installation wherecontaminants are stored

a-7

Indoor air quality problems can becaused by lack of adequate house-keeping practices. On the other hand,deodorizers, cleansers and otherproducts can also produce odors andcontaminants.

iiiMitigating 1AQ Problems 97

Problem #12:Specialized Use Areas asSources of Contaminants

lt

This chemical storage room should bemaintained under negative pressure.Properly designed and maintained localexhaust will achieve the proper airpressure relationship with surroundingareas. Otherwise, such storage areascan be a source of occupant exposure tomany airborne contaminants.

98 Section7 112

Examples

Food preparationArt or print roomsLaboratories

Solutions

Change pollutant pathway relationships

run specialized use area under negativepressure relative to surrounding areasinstall local exhaust, adjust HVACsystem to provide make-up air, and testto verify performance

Remove source by ceasing, relocating, orrescheduling incompatible activities

Reduce source by selecting materials tominimize emissions of contaminantswhile maintaining adequate safety andefficacy

Reduce source by using proper sealingand storage for materials that emitcontaminants

Problem #13:Remodeling or RepairActivities Produce Problems

Examples

Temporary activities produce odors andcontaminants

installation of new particleboard,partitions, carpet, or furnishingspaintingreroofmgdemolition

Existing HVAC system does not provideadequate ventilation for new occupancyor arrangement of space

Solutions

Modify ventilation to preventrecirculation of contaminants

install temporary local exhaust inwork area, adjust HVAC system toprovide make-up air, and test toverify performanceseal off returns in work areaclose outdoor air damper duringre-roofing

Reduce source by scheduling work forunoccupied periods and keeping ventila-tion system in operation to remove odorsand contaminants

Reduce source by careful materialsselection and installation

select materials to minimize emissionsof contaminants while maintainingadequate safety and efficacyhave supplier store new furnishings in aclean, dry, well-ventilated area untilVOC outgassing has diminishedrequest installation procedures (e.g.,adhesives) that limit emissions ofcontaminants

Modify HVAC or wall partition layout ifnecessary

partitions should not interrupt airflowrelocate supply and return diffusersadjust supply and return air quantitiesadjust total air and/or outdoor air supplyto serve new occupancy

113


Remodeling may involvemany activities that cancause IAQ problems.Ventilation modificationscan be used to isolate thework area and preventpollutant build-up inoccupied spaces. Properstorage practices canminimize the release ofcontaminants.

Problem #14:Combustion Gases

Combustion odors can indicate theexistence of a serious problem. Onecombustion product, carbon monoxide, isan odorless gas. Carbon monoxidepoisoning can be life-threatening.

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Air intakes are frequently located nearthe loading dock for aesthetic reasons.Unfortunately, this air intake placementcan draw car and truck exhaust into thebuilding, causing a variety of indoor airquality complaints.

100 Section 7 114

Examples

Vehicle exhaust

offices above (or connected to) anunderground parking garagerooms near (or connected by pathwaysto) a loading dock or service garage

Combustion gases from equipment(e.g., spillage from inadequately ventedappliances, cracked heat exchanger, re-entrainment because local chimney is toolow)

areas near a mechanical roomdistributed throughout zone or entirebuilding

Solutions

Seal to remove pollutant pathway

close openings between the contaminantsource and the occupied spaceinstall well-sealed doors with automaticclosers between the contaminant sourceand the occupied space

Remove source

improve maintenance of combustionequipmentmodify venting or HVAC system toprevent backdraftingrelocate holding area for vehicles atloading dock, parking areaturn off engines of vehicles that arewaiting to be unloaded

Modify ventilation system

install local exhaust in undergroundparking garage (adjust HVAC system toprovide make-up air and test to verifyperformance)relocate fresh air intake (move awayfrom source of contaminants)elevate chimney exhaust outlet

Modify pressure relationships

pressurize spaces around area containingsource of combustion gases

Problem #15:Serious Building-RelatedIllness

Some building-related illnesses can be life-threatening. Even a single confirmeddiagnosis (which involves results fromspecific medical tests) should provoke animmediate and vigorous response.

Examples

Legionnaire's disease(Note: If you suspect Legionnaire'sdisease, call the local public healthdepartment, check for obvious problemsites, and take corrective action. There isno way to be certain that a single case ofthis disease is associated with buildingoccupancy; therefore, public healthagencies usually do not investigate singlecases. Watch for new cases.)

Hypersensitivity pneumonitis(Note: Affected occupant(s) should beremoved and may not be able to returnunless the causative agent is removed fromthe affected person's environment.)

Solutions

Work with public health authorities

evacuation may be recommended orrequired

Remove source

drain, clean, and decontaminate drippans, cooling towers, room unit airconditioners, humidifiers, dehumidifiers,and other habitats of Legionella, fungi,and other organisms using appropriateprotective equipment

'".

a.

install drip pans that drain properlyprovide access to all the items that mustbe cleaned, drained, or replaced periodi-callymodify schedule and procedures forimproved maintenance

Discontinue processes that depositpotentially contaminated moisture in airdistribution system

air washinghumidificationcease nighttime shutdown of air handlers

115Mitigating IAQ Problems 101

This air intake is locatedbetween the coolingtowers. If the water in thecooling towers becomescontaminated withLegionella, there ispotential for Legionnaire'sdisease in the building.

The most economicaland successfulsolutions to IAOproblems are thosein which the operat-ing principle of thecorrection strategymakes sense and issuited to the problem.

JUDGING PROPOSEDMITIGATION DESIGNSAND THEIR SUCESS

Mitigation efforts should be evaluated atthe planning stage by considering thefollowing criteria:

permanenceoperating principledegree to which the strategy fits the jobability to institutionalize the solutiondurabilityinstallation and operating costsconformity with codes

Permanence

Mitigation efforts that create permanentsolutions to indoor air problems are clearlysuperior to those that provide temporarysolutions (unless the problems are alsotemporary). Opening windows or runningair handlers on full outdoor air may besuitable mitigation strategies for a tempo-rary problem such as outgassing of volatilecompounds from new furnishings, butwould not be good ways to deal withemissions from a print shop. A permanentsolution to microbiological contaminationinvolves not only cleaning and disinfec-tion, but also modification of the environ-ment to prevent regrowth.

Operating Principle

The most economical and successfulsolutions to IAQ problems are those inwhich the operating principle of thecorrection strategy makes sense and issuited to the problem. If a specific pointsource of contaminants has been identified,treatment at the source (e.g., by removal,sealing, or local exhaust) is almost alwaysa more appropriate correction strategy thandilution of the contaminant by increasedgeneral ventilation. If the IAQ problem iscaused by the introduction of outdoor airthat contains contaminants, increasedgeneral ventilation will only make the

102 Section 7

situation worse (unless the outdoor air iscleaned).

Degree to Which the StrategyFits the Job

It is im.portant to make sure that youunderstand the IAQ problem well enoughto select a correction strategy whose sizeand scope fit the job.rif odors from aspecial use area such as a kitchen arecausing complaints'in' a nearby office,increasing the ventilation rate in the officemay not be a successful approach. Themitigation strategy should address theentire area affected.

If mechanical equipment is needed to'correct the IAQ problem, it must bepowerful enough to accoMplish the task.For example, a local exhaust systemshould be strong enough and close enoughto the source so that none of the contami-nant is drawn into nearby returns andrecirculated.

Ability to Institutionalizethe Solution

A mitigation strategy will be most success-ful when it is institutionalized as part ofnormal building operations. Solutions thatdo not require exotic equipment are morelikely to be successful in the long run thanapproaches that involve unfamiliarconcepts or delicately maintained systems.If maintenance or housekeeping proce-dures or supplies must change as part ofthe mitigation, it may be necessary to planfor additional staff training, new inspectionchecklists, or modified purchasing prac-tices. Operating schedules for HVACequipment may also require modification.

Durability

IAQ mitigation strategies that are durableand low-maintenance are more attractive toowners and building staff than approachesthat require frequent adjustment or

11G

specialized maintenance skills. New itemsof equipment should be quiet, energy-efficient, and durable, so that the operatorsare encouraged to keep them running.

Installation and Operating Costs

The approach with the lowest initial costmay not be the least expensive over thelong run. Other economic considerationsinclude: energy costs for equipment opera-tion; increased staff time for maintenance;differential cost of alternative materialsand supplies; and higher hourly rates ifodor-producing activities (e.g., cleaning)must be scheduled for unoccupied periods.Although these costs will almost certainlybe less than the cost of letting the problemcontinue, they are more readily identifi-able, so an appropriate presentation tomanagement may be required.

Conformity with Codes

Any modification to building componentsor mechanical systems should be designedand installed in keeping with applicablefffe, electrical, and other building codes.

Judging the Success of aMitigation Effort

Two kinds of criteria can be used to judgethe success of an effort to correct an indoorair problem:

reduced complaintsmeasurement of properties of the indoorair (often only of limited usefulness)

Reduction or elimination of complaintsappears to be a clear indication of success,but that is not necessarily the case.Occupants who see that their concerns arebeing heard may temporarily stop report-ing discomfort or health symptoms, even ifthe actual cause of their complaints has notbeen addressed. Lingering complaints mayalso continue after successful mitigation ifpeople have become upset over the

MANAGING MITIGATION PROJECTSINVOLVING SEVERE CONTAMINATION

Elements Cautions

Identify the extent ofcontamination

Locating the original source of achemical release or microbiologicalgrowth may only be the tip of theiceberg. Pollutants often tend tomigrate through a building and collectin "sinks", from which they can beresuspended into the air. For ex-ample, particles accumulate onhorizontal surfaces that are not subjectto regular housekeeping; odors mayadsorb (stick) to porous materials.Detailed surface and/or bulk samplingmay be needed to locate such "sec-ondary" sources in order to solve anair quality problem.

Develop a precise scope ofwork specifying exactlyhow remediation will beperformed

Depending on the problem, a detailedknowledge of chemistry, microbiol-ogy, building science, and health andsafety may be required.

Monitor remediation toensure work practices arefollowed

Include air sampling along withregular inspections if needed. Decon-tamination of areas within an occu-pied building is especially critical.

Conduct clearancesampling

In the event of severe contamination,representative air samples should becollected to ensure that key indicatorshave returned to background levelsand that the space can be safelyreoccupied.

Many routine MO problems can becorrected by a common sense approachnot requiring special expertise. How-ever, when complex exposure orcontamination issues are involved, moredetailed technical assistance may beneeded for successful remediation.Efforts such as those outlined aboveare sometimes needed to deal withsevere contamination.

117


If you have madeseveral unsuccessfulefforts to control aproblem, then it maybe advisable to seekoutside assistance.

handling of the problem. Ongoing (butreduced) complaints could also indicatethat there were multiple IAQ problems andthat one or more problems are still unre-solved.

However, it can be very difficult to usemeasurements of contaminant levels as ameans of determining whether air qualityhas improved. Concentrations of indoorair pollutants typically vary greatly overtime; further, the specific contaminantmeasured may not be causing the problem.If air samples are taken, readings takenbefore and after mitigation should beinterpreted cautiously. It is important tokeep the "before" and "after" conditions asidentical as possible, except for theoperation of the control strategy. Forexample, the same HVAC operation,building occupancy and climatic condi-tions should apply during both measure-ment periods. "Worst-case" conditionsidentified during the investigation shouldbe used.

Measurements of airflows, ventilationrates, and air distribution patterns are themore reliable methods of assessing theresults of control efforts. Airflow mea-surements taken during the buildinginvestigation can identify areas with poorventilation; later they can be used toevaluate attempts to improve the ventila-tion rate, distribution, or direction of flow.Studying air distribution patterns will showwhether a mitigation strategy has success-fully prevented a contaminant from beingtransported by airflow.

Persistent Problems

Solving an indoor air quality problem is acyclical process of data collection and

104 Section 7

hypothesis testing. Deeper and moredetailed investigation is needed to suggestnew hypotheses after any unsuccessful orpartially-successful control attempt.

Even the best-planned investigationsand mitigation actions may not produce aresolution to the problem. You may havemade a careful investigation, found one ormore apparent causes for the problem, andimplemented a control system. Nonethe-less, your correction strategy may not havecaused a noticeable reduction in theconcentration of the contaminant orimprovement in ventilation rates orefficiency. Worse, the complaints maypersist even though you have beensuccessful at improving ventilation andcontrolling all of the contaminants youcould identify. When you have pursuedsource control options and have increasedventilation rates and efficiency to the limitsof your expertise, you must decide howimportant it is to pursue the problemfurther.

If you have made several unsuccessfulefforts to control a problem, then it may beadvisable to seek outside assistance. Theproblem is probably fairly complex, and itmay occur only intermittently or cross theborders that divide traditional fields ofknowledge. It is even possible that poorindoor air quality is not the actual cause ofthe complaints. Bringing in a newperspective at this point can be veryeffective.

The next section provides guidance onhiring professional indoor air qualityassistance. An interdisciplinary team (suchas people with engineering and medical orhealth backgrounds) may be needed tosolve particularly difficult problems.

113

Hiring Professional Assistance toSolve an IAQ Problem

Many IAQ problems are simple toresolve when facility staff have beeneducated about the investigation process.In other cases, however, a time comeswhen outside assistance is needed. Profes-sional help might be necessary or desirablein the following situations, among others:

Mistakes or delays could have seriousconsequences (e.g., health hazards,liability exposure, regulatory sanctions).Building management feels that an inde-pendent investigation would be betterreceived or more effectively documentedthan an in-house investigation.Investigation and mitigation efforts byfacility staff have not relieved theIAQ problem.Preliminary findings by staff suggest theneed for measurements that requirespecialized equipment and trainingbeyond in-house capabilities.

You may be able to find help bylooking in the yellow pages of yourtelephone book (e.g., under "Engineers,""Environmental Services," "Laboratories -Testing," or "Industrial Hygienists").Local or State health or air pollutionagencies may have lists of firms offeringIAQ services in your area. It may also beuseful to seek out referrals from otherbuilding management firms.

Local, State, or Federal governmentagencies may be able to provide expertassistance or direction in solving IAQproblems. It is particularly important tocontact your local or State HealthDepartment if you suspect that you have aserious building-related illness potentiallylinked to biological contamination in yourbuilding.

If available government agencies do nothave personnel with the appropriate skills

to assist in solving your IAQ problem, theymay be able to direct you to firms in yourarea with experience in indoor air qualitywork. Note that even certifiedprofessionals from disciplines closelyrelated to IAQ issues (such as industrialhygienists, ventilation engineers, andtoxicologists) may not have the specificexpertise needed to investigate and resolveindoor air problems. Individuals or groupsthat offer services in this evolving fieldshould be questioned closely about theirrelated experience and their proposedapproach to your problem.

As with any hiring process, the betteryou know your own needs, the easier itwill be to select a firm or individual toservice those needs. Firms and individualsworking in IAQ may come from a varietyof disciplines. Typically, the skills ofHVAC engineers and industrial hygienistsare useful for this type of investigation,although input from other disciplines suchas chemistry, chemical engineering,architecture, microbiology, or medicinemay also be important. If problems otherthan indoor air quality are involved,experts in lighting, acoustic design, interiordesign, psychology, or other fields may behelpful in resolving occupant complaintsabout the indoor environment.

MAKE SURE THAT THEIRAPPROACH FITS YOUR NEEDS

As you prepare to hire professionalservices in the area of indoor air quality, beaware it is a developing area of knowledge.Most consultants working in the fieldreceived their primary training in otherareas. A variety of investigative methodsmay be employed, many of which areineffective for resolving any but the most

As you prepare to hireprofessional servicesin the area of indoorair quality, be awarethat it is a developingarea of knowledge.

Hiring ProfessionalLlace to Solve an IAQ Problem 105

Diagnostic outcomesto avoid include anevaluation that over-emphasizes measur-ing concentrations ofpollutants and areport that links allthe deficiencies in thebuilding to theproblem withoutconsidering theiractual associationwith the complaints .

obvious situations. Inappropriately designedstudies may lead to conclusions that areeither false negative (e.g., falsely con-cludes that there is no problem associatedwith the building) or false positive (e.g.,incorrectly attributes the cause to buildingconditions).

Diagnostic outcomes to avoid include:an evaluation that overemphasizesmeasuring concentrations of pollutantsand comparing those concentrations tonumerical standards, anda report that lists a series of major andminor building deficiencies and links allthe deficiencies to the problem withoutconsidering their actual association withthe complaints

Considerable care should be exercisedwhen interviewing potential consultants toavoid those subscribing to these strategies.A qualified IAQ investigator should haveappropriate experience, demonstrate abroad understanding of indoor air qualityproblems and the conditions which canlead to them, and use a phased diagnosticapproach.

SELECTION CRITERIA

Most of the criteria used in selecting aprofessional to provide indoor air qualityservices are similar to those used for otherprofessionals:

company experience in solving similarproblems, including training andexperience of the individuals who wouldbe responsible for the workquality of interview and proposalcompany reputationknowledge of local codes and regionalclimate conditionscost

106 Section 8

120

Experience

An EPA survey of firms providing IAQservices found that almost half had beenproviding IAQ diagnostic or mitigationservices in non-industrial settings for ten orfewer years.

Ask how much IAQ work and what typeof IAQ work the firm has done.Have the firm identify the personnel whowould be responsible for your case, theirspecific experience, and relatedqualifications. Contract only for theservices of those individuals, or requireapproval for substitutions.

Quality of Interview andProposal

Several guidelines may be of assistance inhiring IAQ professionals.

1. Competent professionals will askquestions about your situation to seewhether they feel they can offer servicesthat will assist you.

The causes and potential remedies forindoor air quality problems vary greatly.A firm needs at least a preliminaryunderstanding of the facts about what isgoing on in your building to evaluate if ithas access to the professional skillsnecessary to address your concerns and tomake effective use of its personnel fromthe outset. Often a multi-disciplinary teamof professionals is needed.

2. The proposal for the investigationshould emphasize observations ratherthan measurements.

Section 6 describes the four types ofinformation that may need to be gatheredin an investigation in order to resolve anindoor air quality problem: the occupantcomplaints, the HVAC system, pollutantpathways, and pollutant sources. There isalso a discussion of the role of monitoring

within an investigation. Non-routinemeasurements (such as relatively expen-sive sampling for VOCs) should not beprovided without site-specific justification.

3. The staff responsible for building in-vestigation should have a good under-standing of the relationship between IAQand the building structure, mechanicalsystems, and human activities.

For example, lack of adequate ventila-tion is at least a contributing factor inmany indoor air quality problem situations.Evaluating the performance of the ventila-tion system depends on understanding theinteraction between the mechanical systemand the human activity within the building.

In some cases building investigatorsmay have accumulated a breadth ofknowledge. For example, a mechanicalengineer and an industrial hygienist seebuildings differently. However, amechanical engineer with several years ofexperience in IAQ problem investigationsmay have seen enough health-relatedproblems to cross the gap; likewise, anindustrial hygienist with years ofexperience studying problems in an officesetting may have considerable expertise inHVAC and other building mechanicalsystems.

Either in the proposal or in discussion,the consultant should:

Describe the goal(s), methodology, andsequence of the investigation, theinformation to be obtained, and theprocess of hypothesis development andtesting, including criteria for decision-making about further data-gathering.The proposal should include an explana-tion of the need for any proposedmeasurements. The goal is to reach asuccessful resolution of the complaints,not simply to generate data.Identify any elements of the work thatwill require a time commitment from theclient's own staff, including information

to be collected by the client.Identify additional tasks (and costs)which are pan of solving the IAQproblem but are outside the scope of thecontract. Examples might includemedical examination of complainants,laboratory fees, and contractor's fees formitigation work.Describe the schedule, cost, and workproduct(s), such as a written report,specifications, and plans for mitigationwork; supervision of mitigation work;and training program for building staff.Discuss communication between theIAQ professional and the client: Howoften will thecontractor discuss theprogress of the work with the client?Who will be notified of test results andother data? Will communications be inwriting, by telephone, or face-to-face?Will the consultant meet with buildingoccupants to collect information? Willthe consultant meet with occupants to .

discuss findings if requested to do so?

Reputation

There are no Federal regulations coveringprofessional services in the general field ofindoor air quality, although some disci-plines (e.g., engineers, industrial hygien-ists) whose practitioners work with IAQproblems have licensing and certificationrequirements.

Building owners and managers whosuspect that they may have a problem witha specific pollutant (such as radon,asbestos, or lead) may be able to obtainassistance from local and State HealthDepartments. Government agencies andaffected industries have developed trainingprograms for contTactors who diagnose ormitigate problems with these particularcontaminants.

Firms should be asked to provide refer-ences from clients who have receivedcomparable services. In exploring refer-

I 2 i

The goal of theinvestigative processis to reach a success-ful resolution of thecomplaints, notsimply to generatedata.

Hiring Professional Assistance to Solve an IAQ Problem 107

ences, it is useful to ask about long-termfollow-up. After the contract was com-pleted, did the contractor remain in contactwith the client to ensure that problems didnot recur?

Knowledge of Local Codes andRegional Climate Conditions

Familiarity with State and local regulationsand codes helps to avoid problems duringmitigation. For example, in makingchanges to the HVAC system, it isimportant to conform to local buildingcodes. Heating, cooling, and humiditycontrol needs are differemin differentgeographic regions, and can affect theselection of an appropriate mitigationapproach. Getting assurances that all firmsunder consideration have this knowledgebecomes particularly important if itbecomes necessary to seek expertisefrom outside the local area.

122

108 Section 8

Cost

It is impossible for this document to givespecific guidance on the cost of profes-sional services. If projected costs jumpsuddenly during the investigation process,the consultants should be able to justifythat added cost.

The budget will be influenced by anumber of factors, including:

complexity of the problemsize and complexity of the building andits HVAC system(s)quality and extent of recordkeeping bybuilding staff and managementtype of report or other product requirednumber of meetings required (formalpresentations can be quite expensive)air sampling (e.g., use of instruments,laboratory analysis) if required


APPENDICES/

I

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4: Printed on Recycled Paper

Appendix A:Common IAQ Measurements - A General Guide

The following is a brief introduction tomaking measurements that might beneeded in the course of developing an IAQprofile or investigating an IAQ complaint.Emphasis has been placed on the param-eters most commonly of interest in non-research studies, highlighting the morepractical methods and noting someinappropriate tests to avoid. Most of theinstruments discussed in this section arerelatively inexpensive and readily availablefrom many local safety supply companies.Consult the guidance in Section 6 on pages74-77 before determining whether toproceed with air sampling.

OVERVIEW OF SAMPLINGDEVICES

Air contaminants of concern in IAQ can bemeasured by one or more of the followingmethods:

Vacuum Pump:A vacuum pump with a known airflow ratedraws air through collection devices, suchas a filter (catches airborne particles), asorhent tube (which attracts certainchemical vapors to a powder such ascarbon), or an impinger (bubbles thecontaminants through a solution in a testtube). Tests originated for industrialenvironments typically need to be adjustedto a lower detection limit for 1AQ work.Labs can be asked to report when tracelevels of an identifiable contaminant arepresent below the limit of quantificationand detection.

In adapting an industrial hygienesorbent tube sampling method for IAQ, theinvestigator must consider at least twoimportant questions. First: are theemissions to be measured from a product's

SELECTING MEASUREMENT DEVICES

The growing interest in indoor air quality is stimulating the develop-ment of instruments for IAQ research and building investigations. Asyou evaluate the available measurement devices, it may be helpful toconsider the following criteria:

Ease of useportabilitydirect-reading vs. analysis requiredruggednesstime required for each measurement

Quality assuranceavailability of service and customer supportmaintenance and calibration requirements

Outputtime-averaged vs. instantaneous readingssensitivitycompatibility with computer or data logging accessories

Costsingle use only vs. reusablepurchase vs. rental

end use the same as those of concernduring manufacturing? Second: is itnecessary to increase the air volumesampled? Such an increase may be neededto detect the presence of contaminants atthe low concentrations usually found innon-industrial settings. For example, aninvestigator might have to increasesampling time from 30 minutes to 5 hoursin order to detect a substance at the lowconcentrations found during IAQ investi-gations. In cases where standard samplingmethods are changed, qualified industrialhygienists and chemists should be con-sulted to ensure that accuracy and preci-

sion remain acceptable.

Direct-reading Meter:Direct-reading meters estimate air concen-trations through one of several detection

pcommonIAQ Measurements A General Guide 109

it

Above: A smoke tube, which is one typeof chemical smoke device. Used to ob-serve patterns of air movement and thedirection (negative or positive) of pres-sure differences. Below: A microman-ometer. Used for measuring pressuredifferentials to learn about airflow. Pro-vides quantitative data, as compared tothe qualitative information provided bychemical smoke.

110 Appendix A 12 5

principles. These may report specificchemicals (e.g., CO2 by infrared light),chemical groups (e.g., certain volatileorganics by photoionization potential), orbroad pollutant categories (e.g., all respi-rable particles by scattered light). Detec-tion limits and averaging time developedfor industrial use may or may not be appro-priate for IAQ.

Detector tube kit:Detector tube kits generally include a handpump that draws a known volume of airthrough a chemically treated tube intendedto react with certain contaminants. Thelength of color stain resulting in the tubecorrelates to chemical concentration.

Personal monitoring devices:Personal monitoring devices (sometimesreferred to as "dosimeters") are carried orworn by individuals and are used to mea-sure that individual's exposure to particularchemical(s). Devices that include a pumpare called "active" monitors; devices thatdo not include a pump are called "passive"monitors. Such devices are currently usedfor research purposes. It is possible thatsometime in the future they may also behelpful in IAQ investigations in public andcommercial buildings.

SIMPLE VENTILATION/COMFORTINDICATIONS

Thermal Comfort: Temperatureand Relative Humidity

The sense of thermal comfort (or discom-fort) results from an interaction betweentemperature, relative humidity, air move-ment, clothing, activity level, and indi-vidual physiology. Temperature andrelative humidity measurements areindicators of thermal comfort.

Methodology

Measurements can be made with a simplethermometer and sling psychrometer orwith electronic sensors (e.g., a thermo-hygrometer). Accuracy of within + or - 1°F

is recommended for temperature measure-ments. For each measurement, time shouldbe allowed for the reading to stabilize toroom conditions. Refer to the specifica-tions for the measuring device; some takeseveral minutes to stabilize. Electronicrelative humidity (RH) meters must becalibrated frequently.

Indoor relative humidity is influencedby outdoor conditions. A single indoormeasurement may not be a good indicationof long-term relative humidity in the build-ing. Programmable recording sensors canbe used to gain an understanding of tem-perature or humidity conditions as theychange over time.

Using the Results

Temperature and humidity directly affectthermal comfort. They may also provideindirect indications of HVAC conditionand the potential for airborne contamina-tion from biological or organic com-pounds. There is considerable debateamong researchers, IAQ professionals, andhealth professionals concerning recom-mended levels of relative humidity; how-ever, the humidity levels recommended bydifferent organizations generally rangebetween 30% and 60% RH.

Comparison of indoor and outdoortemperature and humidity readings takenduring complaint periods can indicatewhether thermal discomfort might be dueto extreme conditions beyond the designcapacity of HVAC equipment or the build-ing envelope.

Measure next to thermostats to confirmcalibration. Measure at the location ofcomplaints to evaluate whether or nottemperature and humidity at that locationare within the comfort zone (see Figure 6-2on page 57.

Readings that show large variationswithin the space may indicate a room airdistribution or mixing problem. Readingsthat are highly variable over time mayindicate control or balance problems withthe HVAC systems.

Tracking Air Movement withChemical Smoke

Chemical smoke can be helpful in evaluat-ing HVAC systems, tracking potentialcontaminant movement, and identifyingpressure differentials. Chemical smokemoves from areas of higher pressure toareas of lower pressure if there is anopening between them (e.g., door, utilitypenetration). Because it is heatless,chemical smoke is extremely sensitive toair currents. Investigators can learn aboutairflow patterns by observing the directionand speed of smoke movement. Puffs ofsmoke released at the shell of the building(by doors, windows, or gaps) will indicatewhether the HVAC systems are maintain-ing interior spaces under positive pressurerelative to the outdoors.

Methodology

Chemical smoke is available with variousdispensing mechanisms, including smoke"bottles," "guns," "pencils," or "tubes."The dispensers allow smoke to be releasedin controlled quantities and directed atspecific locations. It is often moreinformative to use a number of small puffsof smoke as you move along an air

A psychrometer. Used tomeasure dry bulb and wetbulb temperatures and todetermine relative humiditybased upon a psychometricchart. The NIOSH protocolfor indoor air investigationsalways includes measure-ment of indoor and outdoorrelative humidity. There aretwo types of psychrometers:aspirated (with a fan) orsling (without a fan).

1°44, 0Common IAQ MeasurementsA General Guide 111

pathway rather than releasing a largeamount in a single puff. (Note: Avoiddirect inhalation of chemical smoke,because it can be irritating. Do not releasesmoke directly on smoke detectors.)

Using the Results

Smoke released mid-room: Observationof a few puffs of smoke released in mid-room or mid-cubicle can help to visualizeair circulation within the space. Dispersalof smoke in several seconds suggests goodair circulation, while smoke that staysessentially still for several secondssuggests poor circulation. Poor aircirculation may contribute to sick buildingsyndrome complaints or may contribute tocomfort complaints even if there issufficient overall air exchange.

Smoke released near diffusers, grilles:Puffs of smoke released near HVAC ventsgive a general idea of airflow. (Is it in orout? Vigorous? Sluggish? No flow?)This is helpful in evaluating the supply andreturn system and determining whetherventilation air actually reaches the breath-ing zone. (For a variable air volumesystem, be sure to take into account howthe system is designed to modulate. Itcould be on during the test, but off formuch of the rest of the day.) "Short-circuiting" occurs when air movesrelatively directly from supply diffusers toreturn grilles, instead of mixing with roomair in the breathing zone. When a substan-tial amount of air short-circuits, occupantsmay not receive adequate supplies ofoutdoor air and source emissions may notbe diluted sufficiently.

Carbon Dioxide (CO2) as anIndicator of Ventilation

CO2 is a normal constituent of the atmo-sphere. Exhaled breath from buildingoccupants is an important indoor CO2source. Indoor CO2 concentrations can,under some test conditions, provide a good

112 Appendix A 127

indication of the adequacy of ventilation.Comparison of peak CO2 readings betweenrooms, between air handler zones, and atvarying heights above the floor, may helpto identify and diagnose various buildingventilation deficiencies.

Methodology

CO2 can be measured with either a direct-reading meter or a detector tube kit. Therelative occupancy, air damper settings,and weather should be noted for eachperiod of CO2 testing.

CO2 measurements for ventilationshould be collected away from any sourcethat could directly influence the reading(e.g., hold the sampling device away fromexhaled breath). Individual measurementsshould be short-term. As with many othermeasurements of indoor air conditions, it isadvisable to take one or more readings in"control" locations to serve as baselines forcomparison. Readings from outdoors andfrom areas in which there are no apparentIAQ problems are frequently used ascontrols. Outdoor samples should be takennear the outdoor air intake.

Measurements taken to evaluate theadequacy of ventilation should be madewhen concentrations are expected to peak.It may be helpful to compare measure-ments taken at different times of day. Ifthe occupant population is fairly stableduring normal business hours, CO2 levelswill typically rise during the morning, fallduring the lunch period, then rise again,reaching a peak in mid-afternoon. In thiscase, sampling in the mid- to late-after-noon is recommended. Other samplingtimes may be necessary for differentoccupancy schedules.

Using the Results

Peak CO2 concentrations above 1000 ppmin the breathing zone indicate ventilationproblems. Carbon dioxide concentrationsbelow 1000 ppm generally indicate thatventilation is adequate to deal with the

routine products of human occupancy.However, there are several reasons not toconclude too quickly that a low CO2reading means no IAQ problem exists.Problems can occur in buildings in whichmeasured CO2 concentrations are below1000 ppm. Although CO2 readingsindicate good ventilation, for example, ifstrong contaminant sources are present,some sort of source control may be neededto prevent IAQ problems. Errors inmeasurement and varying CO2 concentra-tions over time can also cause low readingsthat may be misleading.

Elevated CO2 may be due to variouscauses alone or in combination, such as:increased occupant population, air ex-change rates below ASHRAE guidelines,poor air distribution, and poor air mixing.A higher average CO2 concentration in thegeneral breathing zone (at least two feetfrom exhaled breath) than in the airentering return grilles is an indication ofpoor air mixing. Smoke tubes andtemperature profiles will help to clarify aircirculation patterns.

If CO2 measurements taken before theoccupied period begins are higher thanoutdoor readings taken at the same time,there may be an operating problem withthe HVAC system. Potential problemsinclude the following:

ventilation terminated too early theevening before (as compared with theoccupancy load on the space)combustion by-products from a nearbyroadway or parking garage are drawninto the buildinga gas-fired heating appliance in thebuilding has a cracked heat exchanger

Outdoor CO2 concentrations above 400ppm may indicate an outdoor contamina-tion problem from traffic or other combus-tion sources. Note, however, that detectortubes cannot provide accurate measure-ments of CO2 in hot or cold weather.

.m..------4,

I

-

Measuring Airflow

Measurements of airflow allow investiga-tors to estimate the amount of outdoor airthat is entering the building and to evaluateHVAC system operation. The mostappropriate measurement techniquedepends on the characteristics of themeasurement location.

Methodology

Airflow quantities can be calculated bymeasuring the velocity and cross-sectionalarea of the airstream. For example, if air is

128

A flow hood. Used tomeasure the total air flow(outdoor plus recirculatedair) from a diffuser.

Co Inman IAQ Measurements A General Guide 113

A vacuum pump withattachments for samplingwith a filter, a sorbent tube,and an impinger. Use in anon-industrial setting mayrequire a larger volume ofair. Consult with qualifiedindustrial hygienists andchemists if adaptingsampling methods.

"veil _11"

moving at 100 feet per minute in a 24" x12" duct, the airflow is:

100 feet/minute x 2 square feet duct area= 200 cubic feet/minute

Air velocity can be measured with a pitottube or anemometer. Air velocity withinan airstream is likely to vary considerably.For example, it is extremely difficult tomeasure air velocity at supply diffusersbecause of turbulence around the mixingvanes. The best estimates of air velocitycan be achieved by averaging the results ofa number of measurements. ASTMStandard Practice D 3154 providesguidance on making such measurements.This method is available from ASTM.(See Appendix G for ASTM's address andphone number.) The cross-sectional areaof the airstream is sometimes easy tocalculate (e.g., in a straight run of rectan-gular ductwork), but can be very compli-cated at other locations such as mixingboxes or diffusers.

Flow hoods can be used for directmeasurement of airflows at locations suchas grilles, diffusers, and exhaust outlets.They are not designed for use in ductwork.

Using the Results

Airflow measurements can be used todetermine whether the HVAC system is

114 Appendix A

operating according to design and toidentify potential problem locations.Building investigations often includemeasurements of outdoor air quantities,exhaust air quantities, and airflows atsupply diffusers and return grilles.

Estimating Outdoor AirQuantities

Outdoor air quantities can be evaluated bymeasuring airflow directly. Investigatorsoften estimate the proportion of outdoor airquantities using techniques such as thermalmass balance (temperature) or CO2measurements. Estimation of outdoor airquantity using temperature measurementsis referred to as "thermal balance" orsometimes "thermal mass balance."

Thermal Balance: Methodology

Use of this test requires the followingconditions:

1. Airstreams representing return air,outdoor air, and mixed air (supply airbefore it has been heated or cooled) areaccessible for separate measurement.Some systems are already equipped withan averaging thermometer that is strungdiagonally across the mixed air chamber;the temperature is read out continuously onan instrument panel. Some panels read outsupply, return, outdoor, and/or mixed airtemperature.

2. There is at least a several degreetemperature difference between thebuilding interior and the outdoor air.

3. Total air flow in the air handling systemcan be estimated either by using recentbalancing reports or pitot tube measure-ments in ductwork. 'As an alternative, thesupply air at each diffuser can be estimated(e.g., using a flow measuring hood), andthe results can be summed to calculatetotal system air flow.

Temperature measurements can be madewith a simple thermometer or an electronic

tor3

sensor. Several measurements should betaken across each airstream and averaged.

It is generally easy to obtain a good tem-

perature reading in the outdoor air andreturn airstreams. To obtain a good aver-age temperature reading of the mixed air-stream, a large number of measurements

must be taken upstream of the point at

which the airstream is heated or cooled.

This may be difficult or impossible insome systems.

The percentage or quantity of outdoor airis calculated using thermal measurementsas shown to the right.

Methodology: Carbon DioxideMeasurements

CO2 readings can be taken at supply outlets

or air handlers to estimate the percentage

of outdoor air in the supply airstream. Thepercentage or quantity of outdoor air is cal-

culated using CO, measurements as shownto the right.

Using the Results

The results of this calculation can be

compared to the building design specifica-tions, applicable building codes, or

ventilation recommendations such as

ASHRAE 62-1989 (see page 136 inAppendix B) to see whether under-

ventilation appears to be a problem.

AIR CONTAMINANTCONCENTRATIONS

Volatile Organic Compounds(VOCs)

Hundreds of organic (carbon-containing)

chemicals are found in indoor air at tracelevels. VOCs may present an IAQproblem when individual organics ormixtures exceed normal backgroundconcentrations.

ESTIMATING OUTDOOR AIR QUANTITIES

Using Thermal Mass Balance

TTreturnOutdoor air (percent) air mi xed air x100

return air joutdoor air

Where: T = temperature (degrees Farenheit)

Using Carbon Dioxide MeasurementsCR-CR

Outdoor air (percent) L x 100Co-CR

Where: Cs = ppm CO2 in the supply air (if measured in a room), OrCs = ppm of CO2 in the mixed air (if measured at an air

handler)= ppm of CO2 in the return air= ppm of CO2 in the outdoor air

(All these concentrations must be measured, not assumed.)

Converting Percent To CFM

Outdoor air (percent)Outdoor air (cfm) =

100

Where: cfm = cubic feet per minute

x total airflow (cfm)

The number used for total airflow may be the air quantity supplied toa room or zone, the capacity of an air handler, or the total airflow ofthe HVAC system. Note: The actual amount of airflow in an airhandler is often different from the quantity in design documents.

Methodology: Total Volatile OrganicCompounds (TVOCs)

Several direct-reading instruments areavailable that provide a low sensitivity"total" reading for different types oforganics. Such estimates are usually

presented in parts per million and are

calculated with the assumption that all

chemicals detected are the same as the one

used to calibrate the instrument. Aphotoionization detector is an example of adirect-reading instrument used as a

screening tool for measuring TVOCs.A laboratory analysis of a sorbent tube

can provide an estimate of total solvents in

130Common IAQ Measurements A General Guide 115

the air. Although methods in this categoryreport "total volatile organic compounds"(TVOCs) or "total hydrocarbons" (THC),analytical techniques differ in theirsensitivity to the different types of organ-ics. (For discussion of measurementdevices and their sensitivity, see Overviewof Sampling Devices on page 109.)

Using the Results

Different measurement methods are usefulfor different purposes, but their resultsshould generally not be compared to eachother. Direct-reading instruments do notprovide sufficient sensitivity to differenti-ate normal from problematic mixtures oforganics. However, instantaneous readoutsmay help to identify "hot spots," sources,and pathways. TVOCs or THC deter-mined from sorbent tubes provide moreaccurate average readings, but are unableto distinguish peak exposures. A direct-reading instrument can identify peakexposures if they happen to occur duringthe measurement period.

Methodology: Individual VolatileOrganic Compounds (VOCs)

High concentrations of individual volatileorganic compounds (VOCs) may alsocause IAQ problems. Individual VOCscan be measured in indoor air with amoderate degree of sensitivity (i.e.,measurement in parts per million) throughadaptations of existing industrial airmonitoring technology. Examples ofmedium sensitivity testing devices includeXAD-4 sorbent tubes ( for nicotine),charcoal tubes (for solvents), andchromosorb tubes (for pesticides). After asufficient volume of air is pumped throughthese tubes, they are sent to a lab forextraction and analysis by gaschromatography. Variations use a passivedosimeter (charcoal badge) to collect thesample or a portable gas chromatographonsite for direct injection of building air.These methods may not be sensitive

116 Appendix A 1 9

enough to detect many trace level organicspresent in building air.

High sensitivity techniques haverecently become available to measure"trace organics" VOCs in the air (i.e.measurements in parts per billion.)Sampling may involve Tenax and multiplesorbent tubes, charcoal tubes, evacuatedcanisters, and other technology. Analysisinvolves gas chromatography followed bymass spectroscopy.

Using the Results

Guidelines for public health exposure (asopposed to occupational exposure) for afew VOCs are available in the WorldHealth Organization (WHO) Air QualityGuidelines for Europe. These guidelinesaddress noncarcinogenic and carcinogeniceffects. Occupational exposure standardsexist for many other VOCs. No rule-of-thumb safety factor for applying theseoccupational limits to general IAQ iscurrently endorsed by EPA and NIOSH.

Measurement of trace organics mayidentify the presence of dozens to hundredsof trace VOCs whose significance isdifficult to determine. It may be helpful tocompare levels in complaint areas to levelsin outdoor air or non-complaint areas.

Formaldehyde

Formaldehyde is a VOC that has beenstudied extensively. Small amounts offormaldehyde are present in most indoorenvironments. Itching of the eyes, nose, orthroat may indicate an elevated concentra-tion. Sampling may be helpful whenrelatively new suspect materials arepresent.

Methodology

A number of measurement methods areavailable. Sensitivity and sampling timeare very important issues in selecting amethod; however, many methods allowdetection of concentrations well below

0.1 ppm (see Using the Results below).Measurement of short-term peaks (arounda two-hour sample time) is ideal forevaluating acute irritation. Dosimetersmay accurately record long-term exposurebut may miss these peaks.

Two commonly used methods that aregenerally acceptable for IAQ screeninginvolve impingers and sorbent tubes.Other appropriate methods are alsoavailable.

Using the Results

Various guidelines and standards areavailable for formaldehyde exposure.Several organizations have adopted0.1 ppm as guidance that providesreasonable protection against irritationaleffects in the normal population.Hypersensitivity reactions may occur atlower levels of exposure. Worst-caseconditions are created by minimumventilation, maximum temperatures, andhigh source loadings.

Biological Contaminants

Human health can be affected by exposureto both living and non-living biologicalcontaminants. The term "bioaerosols"describes airborne material that is or wasliving, such as mold and bacteria, parts ofliving organisms (e.g., insect body parts),and animal feces.

Testing for biological contaminantsshould generally be limited to:

cases where a walkthrough investigationor human profile study suggests micro-biological involvementcases in which no other pollutant orphysical condition can account forsymptoms

Methodology

Inspection of building sanitary conditionsis generally preferred over sampling,because direct sampling can producemisleading results. Any sampling shouldbe accompanied by observations of

sanitary conditions and a determination asto whether any health problems appearlikely to be related to biological contami-nation.

No single technique is effective forsampling the many biological contami-nants found in indoor environments. Avariety of specific approaches are used toretrieve, enumerate, and identify each kindof microorganism from water, surfaces,and air. Other specific methods are usedfor materials such as feces or insect parts.The utility of these techniques dependsupon their use by professionals who have athorough understanding of the sample siteand the target organism.

Where air sampling is desired, severalapproaches are available. The mostcommon type of air sampler uses a pumpto pull air across a nutrient agar, which isthen incubated. Any bacterial or fungalcolonies that subsequently grow can becounted and identified by a qualifiedmicrobiologist. Different types of agar andincubation temperatures are used to culturedifferent types of organisms. Only livingorganisms or spores in the air are countedby this method. Settling plates, which aresimply opened to room air and thenincubated, are sometimes used to identifywhich bioaerosols are present in different

Web

'41600

A viable impactor. Used tosample for biologicals.Training is required in orderto analyze the results.

Common IAQ MeasurementsA General Guide 117

132

High-flow indoor particulatesampler. Used to measureparticles 10 microns andsmaller that are readilyinhaled.

a

locations. The drawbacks to this techniqueare that it does not indicate the quantity ofbioaerosols present and that only thebioaerosols that are heavy enough to fallout onto the agar will be recorded.

Using the Results

Quantities and types of bioaerosols canvary greatly over time in any givenbuilding, making sampling results difficultto interpret. Comparison of relativenumbers and types between indoors andoutdoors or between complaint areas andbackground sites can help to establishtrends; however, no tolerance levels orabsolute guidelines have been established.Low bioaerosol results by themselves arenot considered proof that a problem doesnot exist, for a variety of reasons:

the sampling and identification tech-niques used may not be suited to thetype(s) of bioaerosols that are presentbiological growth may have beeninactive during the sampling period

118 Appendix A

the analysis technique used may notreveal non-living bioaerosols (e.g., feces,animal parts) that can cause healthreactions

Airborne Dust

Particles and fibers suspended in the airgenerally represent a harmless backgroundbut can become a nuisance or cause serioushealth problems under some conditions.

Methodology

A variety of collection and analyticaltechniques are available. Dust can becollected by using a pump to draw airthrough a filter. The filter can then beweighed (gravimetric analysis) or exam-ined under a microscope. Direct readoutsof airborne dust are also available (such asusing meters such as those equipped with a"scattered light" detector).

Using the Results

IAQ measurements for airborne dust willbe well below occupational and ambientair guidelines except under the mostextreme conditions. Unusual types orelevated amounts of particles or fibers canhelp identify potential exposure problems.

Combustion Products

Combustion products are released bymotor vehicle exhaust, tobacco smoke, andother sources, and contain airborne dust(see the previous section) along withpotentially harmful gases such as carbonmonoxide and nitrogen oxides.

Methodology

Direct-reading meters, detector tubes, andpassive dosimeters are among the tech-niques most commonly used to measurecarbon monoxide and nitrogen oxides.

133

Using the Results

Comparison with occupational standardswill reveal only whether an imminentdanger exists. Any readings that areelevated above outdoor concentrations orbackground building levels may indicate amixture of potentially irritating combustionproducts, especially if susceptible indi-viduals are exposed.

Other Inorganic Gases

Although they are not routinely sampled inmost IAQ studies, a variety of other gases

may be evaluated where conditionswarrant. Examples might include ammo-nia, ozone, and mercury.

Methodology

EPA, NIOSH, and ASTM referencesshould be consulted for specific samplingtechniques. Detector tubes or impingermethods are applicable in some cases.

Using the Results

No generalization can be applied to thisdiverse group of substances.

134

Common IAQ Measurements A General Guide 119

Appendix B:HVAC Systems and Indoor Air Quality

his appendix provides informationabout specific HVAC system designs andcomponents in relation to indoor airquality. It also serves as introductorymaterial for building owners and managerswho may be unfamiliar with the terminol-ogy and concepts associated with HVAC(heating, ventilating, and air conditioning)system design. Further detailed informa-tion can be found in ASHRAE manualsand guides and in some of the guidancedeveloped by other trade and professionalassociations. (See Guidelines of CareDeveloped by Trade Associations inSection 5.) Additional information can beobtained using Appendix G or throughdiscussion with your facility engineer.

BACKGROUND

All occupied buildings require a supply ofoutdoor air. Depending on outdoorconditions, the air may need to be heatedor cooled before it is distributed into theoccupied space. As outdoor air is drawninto the building, indoor air is exhausted orallowed to escape (passive relief), thusremoving air contaminants.

The term "HVAC.system" is used torefer to the equipment that can provideheating, cooling, filtered outdoor air, andhumidity control to maintain comfortconditions in a building. Not all HVACsystems are designed to accomplish allof these functions. Some buildings relyonly on natural ventilation. Others lackmechanical cooling equipment (AC), andmany function with little or no humiditycontrol. The features of the HVAC systemin a given building will depend on severalvariables, including:

age of the designclimatebuilding codes in effect at the time ofthe designbudget that was available for the projectplanned use of the buildingowners' and designers' individualpreferencessubsequent modifications

HVAC systems range in complexityfrom stand-alone units that serveindividual rooms to large, centrallycontrolled systems serving multiple zonesin a building. In large modern officebuildings with heat gains from lighting,people, and equipment, interior spacesoften require year-round cooling. Roomsat the perimeter of the same building (i.e.,rooms with exterior walls, floors, or roofsurfaces) may need to be heated and/orcooled as hourly or daily outdoor weatherconditions change. In buildings over onestory in height, perimeter areas at the lowerlevels also tend to experience the greatestuncontrolled air infiltration.

:111

Working with the electricalcomponents of an HVACsystem involves the risk ofelectrocution and fire. Aknowledgeable member ofthe building staff shouldoversee the inspection ofthe HVAC controls.

#

Mil

Q P.;HVAC Syste4s tthendoor Air Quality 121

Some buildings use only naturalventilation or exhaust fans to remove odorsand contaminants. In these buildings,thermal discomfort and unacceptableindoor air quality are particularly likelywhen occupants keep the windows closedbecause of extreme hot or cold tempera-tures. Problems related to underventilationare also likely when infiltration forces areweakest (i.e., during the "swing seasons"and summer months).

Modern public and commercial build-ings generally use mechanical ventilationsystems to introduce outdoor air during theoccupied mode. Thermal comfort iscommonly maintained by mechanicallydistributing conditioned (heated or cooled)air throughout the building. In somedesigns, air systems are supplemented bypiping systems that carry steam or water tothe building perimeter zones. As thisdocument is concerned with HVACsystems in relation to indoor air quality,the remainder of this discussion will focuson systems that distribute conditioned airto maintain occupant comfort.

Roles of the HVAC SystemOperator and Facility Manager

The system operator(s) and facilitymanager(s) (or IAQ manager) are amongthe most significant factors in determiningwhether IAQ problems will occur in aproperly designed, constructed, andcommissioned HVAC system. HVACsystems require preventive maintenance andprompt repairs if they are to operatecorrectly and provide comfortable condi-tions. The operator(s) must have anadequate understanding of the overallsystem design and its limitations. TheHVAC system capacity and distributioncharacteristics should be evaluated beforerenovations to the building, changes in itsoccupancy, or changes in the use of an area.

System operators must be able torespond appropriately to occupant com-plaints. For example, if an occupant

122 Appendix B

complains that it is too cold or too hot andthe'observed (measured) conditions areoutside of the ASHRAE comfort zone,then the HVAC system needs to beevaluated. Sometimes the problem can berelieved by fine tuning or repairing theHVAC system, but in some cases thesystem cannot perform as expected, and along-term solution must be investigated.

TYPES OF HVAC SYSTEMS

Single Zone

A single air handling unit can only servemore than one building area if the areasserved have similar heating, cooling, andventilation requirements, or if the controlsystem compensates for differences inheating, cooling, and ventilation needsamong the spaces served. Areas regulatedby a common control (e.g., a singlethermostat) are referred to as zones.Thermal comfort problems can result if thedesign does not adequately account fordifferences in heating and cooling loadsbetween rooms that are in the same zone.This can easily occur if:

The cooling load in some area(s) with-in a zone changes due to an increasedoccupant population, increased lighting,or the introduction of new heat-produc-ing equipment (e.g., computers, copiers).Areas within a zone have different solarexposures. This can produce radiant heatgains and losses that, in turn, createunevenly distributed heating or coolingneeds (e.g., as the sun angle changesdaily and seasonally).

Multiple Zone

Multiple zone systems can provide eachzone with air at a different temperature byheating or cooling the airstream in eachzone. Alternative design strategies involvedelivering air at a constant temperaturewhile varying the volume of airflow, ormodulating room temperature with a

130

supplementary system (e.g., perimeter hotwater piping).

Constant VolumeConstant volume systems, as their namesuggests, generally deliver a constant

airflow to each space. Changes in space

temperatures are made by heating or

cooling the air or switching the air han-dling unit on and off, not by modulatingthe volume of air supplied. These systemsoften operate with a fixed minimumpercentage of outdoor air or with an "aireconomizer" feature (described in theOutdoor Air Control discussion thatfollows).

Variable Air VolumeVariable air volume systems maintainthermal comfort by varying the amount ofheated or cooled air delivered to eachspace, rather than by changing the air

temperature. (However, many VAVsystems also have provisions for resettingthe temperature of the delivery air on a

seasonal basis, depending on the severity

of the weather). Overcooling oroverheating can occur within a given zoneif the system is not adjusted to respond to

the load. Underventilation frequentlyoccurs if the system is not arranged to

introduce at least a minimum quantity (asopposed to percentage) of outdoor air as

the VAV system throttles back from fullairflow, or if the system supply airtemperature is set too low for the loads

present in the zone.

BASIC COMPONENTS OF ANHVAC SYSTEM

The basic components of an HVAC system

that delivers conditioned air to maintainthermal comfort and indoor air quality are:

outdoor air intakemixed-air plenum and outdoor air control

air filterheating and cooling coils

humidification and/or de-humidificationequipment

TESTING AND BALANCING

Modern HVAC systems typically use sophisticated, automatic controlsto supply the proper amounts of air for heating, cooling, and ventila-tion in commercial buildings. Problems during installation, operation,maintenance, and servicing of the HVAC system could prevent it fromoperating as designed. Each system should be tested to ensure itsinitial and continued performance. In addition to providing acceptablethermal conditions and ventilation air, a properly adjusted andbalanced system can also reduce operating costs and increaseequipment life.

Testing and balancing involves the testing, adjusting, and balanc-ing of HVAC system components so that the entire system providesairflows that are in accordance with the design specifications. Typicalcomponents and system parameters tested include:

all supply, return, exhaust, and outdoor airflow ratescontrol settings and operationair temperaturesfan speeds and power consumptionfilter or collector resistance

The typical test and balance agency or contractor coordinates withthe control contractor to accomplish three goals: verify and ensurethe most effective system operation within the design specifications,identify and correct any problems, and ensure the safety of thesystem.

A test and balance report should provide a complete record of thedesign, preliminary measurements, and final test data. The reportshould include any discrepancies between the test data and thedesign specifications, along with reasons for those discrepancies. Tofacilitate future performance checks and adjustments, appropriaterecords should be kept on all damper positions, equipment capacities,control types and locations, control settings and operating logic,airflow rates, static pressures, fan speeds, and horsepowers.

Testing and balancing of existing building systems should beperformed whenever there is reason to believe the system is notfunctioning as designed or when current records do not accuratelyreflect the actual operation of the system. The Associated Air BalanceCouncil recommends the following guidelines in determining whethertesting and balancing is required:

When space has been renovated or changed to provide for newoccupancy.When HVAC equipment has been replaced or modified.When control settings have been readjusted by maintenance orother personnel.After the air conveyance system has been cleaned.When accurate records are required to conduct an IAQ investigation.When the building owner is unable to obtain design documents orappropriate air exchange rates for compliance with IAQ standards orguidelines.

Because of the diversity of system types and the interrelationshipof system components, effective balancing requires a skilled techni-cian with the proper experience and instruments. Due to the nature ofthe work, which involves the detection and remediation of problems,it is recommended that an independent test and balance contractor beused,and that this contractor report directly to the building owner,facility manager, or IAO manager.

HVAC Systems and IndAnr'Ail Quality 123

FIGURE B-1: Typical HVAC System Components

OutdoorAir Intake

Outdoor Air Damper

Exhaust Air

r..--

MixingChamber

Filter1411

00 I Fan

000

[-Damper Actuators

Outdoor Air

Supply AirDiffusers

Temperature Sensor

Humidifier

1 L Freeze Stat

Mixed Air Stat

Heating Coil

Cooling Coil and Drip Pan

I

Air Handling Unit

Return AirGrille

Courtesy of Terry Brennan,Camroden Associates,Oriskany, NY

supply fanductsterminal devicereturn air systemexhaust or relief fans and air outletself-contained heating or cooling unitcontrolboilercooling towerwater chiller

The following discussion of thesecomponents (each of which may occurmore than once in any total HVAC system)emphasizes features that affect indoor airquality. It may be helpful to refer to thissection when using the HVAC Checklists.

124 Appendix B

The illustration above shows thegeneral relationship between many ofthese components: however, manyvariations are possible.

Outdoor Air Intake

Building codes require the introduction ofoutdoor air for ventilation in most build-ings. Most non-residential air handlers aredesigned with an outdoor air intake on thereturn side of the ductwork. Outdoor airintroduced through the air handler can befiltered and conditioned (heated or cooled)before distribution. Other designs mayintroduce outdoor air through air-to-airheat exchangers and operable windows.

138

Indoor air quality problems can beproduced when contaminants enter abuilding with the outdoor air. Rooftop orwall-mounted air intakes are sometimeslocated adjacent to or downwind ofbuilding exhaust outlets or other contami-nant sources. Problems can also result ifdebris (e.g., bird droppings) accumulates atthe intake, obstructing airflow and poten-tially introducing microbiological contami-nants.

If more air is exhausted than isintroduced through the outdoor air intake,then outdoor air will enter the building atany leakage sites in the shell. Indoor airquality problems can occur if the leakagesite is a door to a loading dock, parkinggarage, or some other area associated withpollutants.

Mixed-Air Plenum and OutdoorAir Controls

Outdoor air is mixed with return air (airthat has already circulated through theHVAC system) in the mixed-air plenum ofan air handling unit. Indoor air qualityproblems frequently result if the outdoorair damper is not operating properly (e.g.,if the system is not designed or adjusted toallow the introduction of sufficient outdoorair for the current use of the building). Theamount of outdoor air introduced in theoccupied mode should be sufficient tomeet needs for ventilation and exhaustmake-up. It may be fixed at a constantvolume or may vary with the outdoortemperature.

When dampers that regulate the flow ofoutdoor air are arranged to modulate, theyare usually designed to bring in a mini-mum amount of outdoor air (in theoccupied mode) under extreme outdoortemperature.conditions and to open asoutdoor temperatures approach the desiredindoor temperature. Systems that useoutdoor air for cooling are called "aireconomizer cooling" systems. Aireconomizer systems have a mixed air

tElirr7:

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Iftwaloit

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Above: The air intake in the backgroundis locatedioo close to the sanitary vents(the straight pipes to the left and in thecenter foreground) and the bathroomexhaust vent (next to the sanitary venton the right side). Below: The return airdampers in this mixed-air plenum areopen (top), but the outdoor air damper(left) is almost completely closed. Com-plaints in the building indicate thatunderventilation is a problem.

139HVAC Systems and Indoor Air Quality 125

temperature controller and thermostatthat are used to blend return air (typicallyat 74°F) with outdoor air to reach a mixedair temperature of 55° to 65°F. (Mixed airtemperature settings above 65°F may leadto the introduction of insufficient quanti-ties of outdoor air for office space use.)The mixed air is then further heated orcooled for delivery to the occupied spaces.

Air economizer systems have a sensibleor enthalpy control that signals the outdoorair damper to go to the minimum positionwhen it is too warm or humid outdoors.Note that economizer cycles which do notprovide dehumidification may producediscomfort even when the indoor tempera-ture is the same as the thermostat setting.

If outdoor air make-up and exhaust arebalanced, and the zones served by each airhandler are separated and well defined, it ispossible to estimate the minimum flow ofoutdoor air to each space and compare it toventilation standards such as ASHRAE 62-1989. Techniques used for this evaluationinclude the direct measurement of the

Proper air filtration can play an impor-tant role in protecting the rest of theHVAC system and in maintaining goodindoor air quality in occupied spaces.Air filters should be selected and main-tained to provide maximum filtration,while not overtaxing the supply fancapability or leading to "blow out" situa-tions with no air filtration. Shown aboveare, roll filter (top) and bag, panel andpleated filters (below).

126 Appendix B 140

outdoor air at the intake and the calculationof the percentage of outdoor air by atemperature or CO2 balance. Carbondioxide measured in an occupied space isalso an indicator of ventilation adequacy.Some investigators use tracer gases toassess ventilation quantities and airflowpatterns. There are specific methods foreach of these assessments. See Appendix Afor more information.

Many HVAC designs protect the coilsby closing the outdoor air damper if theairstream temperature falls below thesetpoint of a freezestat. Inadequateventilation can occur if a freezestat tripsand is not reset, or if the freezestat is set totrip at an excessively high temperature.Stratification of the cold outdoor air andwarmer return air in the mixing plenums isa common situation, causing nuisancetripping of the freezestat. Unfortunately,the remedy often employed to prevent thisproblem is to close the outdoor air damper.Obviously, solving the problem in this waycan quickly lead to inadequate outdoor airin occupied parts of the building.

Air Filters

Filters are primarily used to removeparticles from the air. The type and designof a filter determine its efficiency atremoving particles of a given size and theamount of energy needed to pull or pushair through the filter. Filters are rated bydifferent standards and test methods suchas dust spot and arrestance which measuredifferent aspects of performance. See thediscussion of ASHRAE Standard 52-76 onpage 138 of this appendix.

Low efficiency filters (ASHRAE DustSpot rating of 10% to 20% or less) areoften used to keep lint and dust fromclogging the heating and cooling coils of asystem. In order to maintain clean air inoccupied spaces, filters must also removebacteria, pollens, insects, soot, dust, anddirt with an efficiency suited to the use ofthe building. Medium efficiency filters(ASHRAE Dust Spot rating of 30% to

60%) can provide much better filtrationthan low efficiency filters. To maintain theproper airflow and minimize the amount ofadditional energy required to move airthrough these higher efficiency filters,pleated-type extended surface filters arerecommended. In buildings that aredesigned to be exceptionally clean, thedesigners may specify the equipment toutilize both a medium efficiency pre-filterand a high efficiency extended surfacefilter (ASHRAE Dust Spot rating of 85%to 95%). Some manufacturers recommendhigh efficiency extended surface filters(ASHRAE Dust Spot rating of 85%)without pre-filters as the most costeffective approach to minimizing energyconsumption and maximizing air quality inmodern HVAC VAV systems that serveoffice environments.

Air filters, whatever their design orefficiency rating, require regular mainte-nance (cleaning for some and replacementfor most). As a filter loads up withparticles, it becomes more efficient atparticle removal but increases the pressuredrop through the system, thereforereducing airflow. Filter manufacturers canprovide information on the pressure dropthrough their products under differentconditions. Low efficiency filters, ifloaded to excess, will become deformedand even "blow out" of their filter rack.When filters blow out, bypassing ofunfiltered air can lead to clogged coils anddirty ducts. Filtration efficiency can beseriously reduced if the filter cells are notproperly sealed to prevent air frombypassing.

Filters should be selected for theirability to protect both the HVAC systemcomponents and general indoor air quality.In many buildings, the best choice is amedium efficiency, pleated filter becausethese filters have a higher removalefficiency than low efficiency filters, yetthey will last without clogging for longerthan high efficiency filters.

fr

`tirl1/4,41/4

Choice of an appropriate filter andproper maintenance are important tokeeping the ductwork clean. If dirtaccumulates in ductwork and if the relativehumidity reaches the dewpoint (so thatcondensation occurs), then the nutrientsand moisture may support the growth ofmicrobiologicals. Attention to air filters isparticularly important in HVAC systemswith acoustical duct liner, which isfrequently used in air handler fan housingsand supply ducts to reduce sound transmis-sion and provide thermal insulation. Areasof duct lining that have become contami-nated with microbiological growth must bereplaced. (See later discussion of ductsand duct cleaning.) Sound reduction canalso be accomplished with the use ofspecial duct-mounted devices such asattenuators or with active electronic noisecontrol.

Air handlers that are located in difficult-to-access places (e.g., in places whichrequire ladders for access, have inconve-nient access doors to unbolt, or are locatedon roofs with no roof hatch access) will be


Pleated medium efficiencyfilters are often preferredover low efficiency filtersbecause they offer addedprotection to both theHVAC equipment and toindoor air quality, yet theydo not clog as easily ashigh efficiency filters.Medium efficiency filters doneed routine maintenance,however, which the filter inthis photo did not receive.

Without proper installationand maintenance, rust andcorrosion may accumulatein condensate pans underheating and cooling coils.The rust in this pan indi-cates that it was installedwithout a pitch or waspitched in the wrongdirection, so that waterdid not drain out properly.

LE.

more likely to suffer from poor air filtermaintenance and overall poor mainte-nance. Quick release and hinged accessdoors for maintenance are more desirablethan bolted access panels.

Filters are available to remove gasesand volatile organic contaminants fromventilation air; however, these systems arenot generally used in normal occupancybuildings. In specially designed HVACsystems, permanganate oxidizers andactivated charcoal may be used for gaseousremoval filters. Some manufacturers offer"partial bypass" carbon filters and carbonimpregnated filters to reduce volatileorganics in the ventilation air of officeenvironments. Gaseous filters must beregularly maintained (replaced or regener-ated) in order for the system to continue tooperate effectively.

128 Appendix B 142

Heating and Cooling Coils

Heating and cooling coils are placed in theairstream to regulate the temperature of theair delivered to the space. Malfunctions ofthe coil controls can result in thermaldiscomfort. Condensation on under-insulated pipes and leakage in pipedsystems will often create moist conditionsconducive to the growth of molds, fungus,and bacteria.

During the cooling mode (air condition-ing), the cooling coil provides dehumidifi-cation as water condenses from the air-stream. Dehumidification can only takeplace if the chilled fluid is maintained at acold enough temperature (generally below45°F for water). Condensate collects in thedrain pan under the cooling coil and exitsvia a deep seal trap. Standing water willaccumulate if the drain pan system has notbeen designed to drain completely underall operating conditions (sloped toward thedrain and properly trapped). Under theseconditions, molds and bacteria willproliferate unless the pan is cleanedfrequently.

It is important to verify that condensatelines have been properly trapped and arecharged with liquid. An improperlytrapped line can be a source of contamina-tion, depending on where the line termi-nates. A properly installed trap could alsobe a source, if the water in the trapevaporates and allows air to flow throughthe trap into the conditioned air.

During the heating mode, problems canoccur if the hot water temperature in theheating coil has been set too low in anattempt to reduce energy consumption. Ifenough outdoor air to provide sufficientventilation is brought in, that air may notbe heated sufficiently to maintain thermalcomfort or, in order to adequately condi-tion the outdoor air, the amount of outdoorair may be reduced so that there is insuffi-cient outdoor air to meet ventilation needs.

Humidification andDehumidification Equipment

In some buildings (or zones withinbuildings), there are special needs thatwarrant the strict control of humidity (e.g.,operating rooms, computer rooms). Thiscontrol is most often accomplished byadding humidification or dehumidificationequipment and controls. In office facili-ties, it is generally preferable to keeprelative humidities above 20% or 30%during the heating season and below 60%during the cooling season. ASHRAEStandard 55-1981 provides guidance onacceptable temperature and humidityconditions. (See also the discussion ofhumidity levels in Section 6.)

The use of a properly designed andoperated air conditioning system willgenerally keep relative humidities below60% RH during the cooling season, inoffice facilities with normal densities andloads. (See the previous discussion of thecooling coil.)

Office buildings in cool climates thathave high interior heat gains, thermallyefficient envelopes (e.g., insulation), andeconomizer cooling may require humidi-fication to maintain relative humiditywithin the comfort zone. When humidi-fication is needed, it must be added in amanner that prevents the growth of micro-biologicals within the ductwork and airhandlers.

Steam humidifiers should utilize cleansteam, rather than treated boiler water, sothat occupants will not be exposed tochemicals. Systems using media otherthan clean steam must be rigorouslymaintained in accordance with themanufacturer's recommended proceduresto reduce the likelihood of microbiologicalgrowth.

Mold growth problems are more likelyif the humidistat setpoint located in theoccupied space is above 45%. The highlimit humidistat, typically located in theductwork downstream of the point at

Above: Occupants of this buildingcomplained of an intermittent fish tankodor. An investigation showed that thiswater spray humidification system isregularly maintained. The coils arewashed roughly every two weeks usingfresh tap water, eliminating the need forany use of algacides. Below: Furtherinvestigation identified the fact that themaintenance practice was causing theodor problem. This picture of thedownstream side of the coils was takenone day after the washing. A highpressure stream of water caused algaein the water to foam and float for severaldays, coinciding with the occupantcomplaints.


DUCT LEAKAGE

Leakage of air from ducts can cause or exacerbate air quality prob-lems, in addition to wasting energy. In general, sealed duct systemsspecified with a leakage rate of less than 3% will have a superior lifecycle cost analysis and reduce the likelihood of problems associatedwith leaky ductwork. Examples of excessive duct leakage leading toproblems include:

leakage of light troffer-type diffusers at the diffuser/light fixtureinterface when they are installed in a return plenum. Such leakagehas been known to cause gross short-circuiting between supply andreturn, wasting much of the conditioned air. If the "room" thermo-stat is located in the return plenum, the room can be very uncom-fortable while the temperature in the plenum is operating at thecontrol setpoint.

leakage of supply ductwork due to loose-fitting joints and connec-tions or "blow outs" of improperly fabricated seams

leakage of return ducts located in crawl spaces or below slabs,allowing soil gases and molds to enter the ductwork

which water vapor is added, is generallyset at 70% to avoid condensation (with apotential for subsequent mold growth) inthe ductwork. Adding water vapor to abuilding that was not designed forhumidification can have a negative impacton the building structure and theoccupants' health, if condensation occurson cold surfaces or in wall or roof cavities.

Supply Fans

After passing through the coil sectionwhere heat is either added or extracted, airmoves through the supply fan chamber andthe distribution system. Air distributionsystems commonly use ducts that areconstructed to be relatively airtight.Elements of the building construction canalso serve as part of the air distributionsystem (e.g., pressurized supply plenumsor return air plenums located in the cavityspace above the ceiling tiles and below thedeck of the floor above). Proper coordina-tion of fan selection and duct layout duringthe building design and construction phaseand ongoing maintenance of mechanicalcomponents, filters, and controls are allnecessary for effective air delivery.

130 Appendix B 144

Fan performance is expressed as theability to move a given quantity of air(cubic feet per minute or cfm) at a givenresistance or static pressure (measured ininches of water column). Airflow inductwork is determined by the size of theduct opening, the resistance of the ductconfiguration, and the velocity of the airthrough the duct. The static pressure in asystem is calculated using factors for ductlength, speed of air movement and changesin the direction of air movement.

It is common to find some differencesbetween the original design and the finalinstallation, as ductwork must sharelimited space with structural members andother "hidden" elements of the buildingsystem (e.g., electrical conduit, plumbingpipes). Air distribution problems canoccur, particularly at the end of duct runs,if departures from the original designincrease the friction in the system to apoint that approaches the limit of fanperformance. Inappropriate use of longruns of flexible ducts with sharp bends alsocauses excessive friction. Poor systembalancing (adjustment) is another commoncause of air distribution problems.

Dampers are used as controls torestrict airflow. Damper positions may berelatively fixed (e.g., set manually duringsystem testing and balancing) or maychange in response to signals from thecontrol system. Fire and smoke damperscan be triggered to respond to indicatorssuch as high temperatures or signals fromsmoke detectors. If a damper is designedto modulate, it should be checked duringinspections to see that it is at the propersetting. ASHRAE and the Associated AirBalance Council both provide guidance onproper intervals for testing and balancing.

Ducts

The same HVAC system that distributesconditioned air throughout a building candistribute dust and other pollutants,including biological contaminants. Dirt or

dust accumulation on any components ofan air handling system its cooling coils,plenums, ducts, and equipment housing

may lead to contamination of the airsupply.

There is widespread agreement that

building owners and managers should takegreat precautions to prevent dirt, highhumidity, or moisture from entering theductwork; there is less agreement at

present about when measures to clean up

are appropriate or how effective cleaningtechniques are at making long-term

improvements to the air supply or atreducing occupant complaints.

The presence of dust in ductwork does

not necessarily indicate a current microbio-logical problem. A small amount of duston duct surfaces is normal and to beexpected. Special attention should begiven to trying to find out if ducts arecontaminated only where specific prob-lems are present, such as: water damage or

biological growth observed in ducts, debrisin ducts that restricts airflow, or dustdischarging from supply diffusers.

Problems with dust and other contami-nation in the ductwork are a function offiltration efficiency, regular HVAC systemmaintenance, the rate of airflow, and good

housekeeping practices in the occupied

space. Problems with biological pollutantscan be prevented by minimizing dust anddirt build-up, promptly repairing leaks andwater damage, preventing moisture

accumulation in the components that are

supposed to be dry, and cleaning the

components such as the drip pans that

collect and drain water.

In cases where sheet metal ductwork

has become damaged or water-soaked,

building owners will need to undertakeclean-up or repair procedures. Forexample, in cases where the thermal liner

or fiberboard has become water-soaked,

building managers will need to replace theaffected areas. These procedures should

be scheduled and performed in a way that

does not expose building occupants to

increased levels of pollutants and should

be carried out by experienced workers.Correcting problems that allowed theductwork to become contaminated in thefirst place is important. Otherwise, thecorrective action will only be temporary.

The porous surface of fibrous glass duct

liner presents more surface area (which

can trap dirt and subsequently collectwater) than sheet metal ductwork. It istherefore particularly important to payattention to the proper design, installation,filtration, humidity, and Maintenance ofducts that contain porous materials. Inaddition, techniques developed forcleaning unlined metal ducts often are notsuitable for use with fibrous glass thermalliner or fiberboard. Such ducts mayrequirt a special type of cleaning tomaintain the integrity of the duct (i.e., noheavy brushing tools that might fray theinner lining) while removing dirt anddebris.

More research on both the efficacy and

the potential for unintended exposures to

building occupants from various cleaningtechniques is needed before firm guidancecan be provided regarding duct cleaning.

Pay attention to worker safety whenworking with air handling systemsincluding during duct cleaning. Anyworker who may potentially breathe ductcontaminants or biocides should wear

suitable protective breathing apparatus.

Workers who are doing the duct cleaning

should be encouraged to also look forother types of problems, such as holes or

gaps in the ducts that could allow contami-nants to enter the ventilation airstream.

Building managers can obtain more

information on the issue of HVACcontamination and cleaning from theprofessional standards developed by some

trade associations (See Guidelines of CareDeveloped by Professional and TradeAssociations in Section 5 and refer to

Appendix G for a list of organizationswith expertise and materials on theseissues.)


PRELIMINARY RECOMMENDATIONS ON DUCT CLEANING1. Any duct cleaning should bescheduled during periods whenthe building is unoccupied toprevent exposure to chemicals andloosened particles.

The air handling unit should not beused during the cleaning or as anair movement device for thecleaning process. The National AirDuct Cleaning Association recom-mends that the system should berun to allow at least eight airchanges in the occupied spacewhen duct cleaning has beencompleted.

2. Negative air pressure that willdraw pollutants to a vacuumcollection system should bemaintained at all times in the ductcleaning area to prevent migrationof dust, dirt, and contaminantsinto occupied areas.

Where possible, use vacuumequipment or fans during cleaningand sanitizing to make sure thatcleaning vapors are exhausted tothe outside and do not enter theoccupied space.

3. If it is determined that theductwork should be cleaned,careful attention must be given toprotecting the ductwork.When gaining access to sheetmetal ducts for cleaning purposes,it is essential to seal the accesshole properly in order to maintainthe integrity of the HVAC system.Access doors are recommended ifthe system is to be cleanedperiodically, and all access holesshould be identified on thebuilding's mechanical plans.

Particular attention is warrantedwhen cutting fibrous glass ducts,and manufacturers' recommendedprocedures for sealing should befollowed stringently. Use existingduct system openings wherepossible because it is difficult torepair the damage caused bycutting new access entries into theductwork. Large, high volume

vacuum equipment should only beused with extreme care because highnegative pressure together withlimited airflow can collapse ducts.

4. Duct cleaning performed with highvelocity airflow (i.e., greater than6,000 dm) should include gentle,well-controlled brushing of ductsurfaces or other methods todislodge dust and other particles.

Duct cleaning that relies only on ahigh velocity airflow through theducts is not likely to achieve satisfac-tory results because the flow rate atthe duct surface remains too low toremove many particles.

5. Only HEPA filtered (high-efficiencyparticle arrestor) vacuuming equip-ment should be used if the vacuumcollection unit is inside the occupiedspace.

Conventional vacuuming equipmentmay discharge extremely fineparticulate matter back into theatmosphere, rather than collecting it.Duct cleaning equipment that drawsthe dust and dirt into a collection unitoutside the building is also available.People should not be allowed toremain in the immediate vicinity ofthese collection units.

6. If biocides are to be used, thenselect only products registered byEPA for such use, use the productsaccording to the manufacturer'sdirections, and pay careful attentionto the method of application.

At present, EPA accepts claims andtherefore registers antimicrobials foruse only as sanitizers, not disinfec-tants or sterilizers in HVAC systems.(See Appendix F for definitions ofantimicrobials.) There is somequestion about whether there areany application techniques thatwill deposit a sufficient amount ofthe biocide to kill bacteria, germs,or other biologicals that may bepresent. Materials such as deodoriz-ers that temporarily eliminate odorscaused by microorganisms provide

132 Appendix B

only a fresh smell, and are notintended to provide real control ofmicrobiological contaminants.

7. Use of sealants to cover interiorductwork surfaces is not recom-mended.

No application techniques havebeen demonstrated to provide acomplete or long-term barrier tomicrobiological growth, nor havesuch materials been evaluated fortheir potential health effects onoccupants. In addition, usingsealants alters the surface burningcharacteristics of the duct materialand may void the fire safety ratingof the ductwork.

8. Careful cleaning and sanitizing ofany parts of coils and drip pans canreduce microbiological pollutants.Prior to using sanitizers, deodoriz-ers, or any cleansing agents,carefully read the directions on theproduct label. Once cleaned, thesecomponents should be thoroughlyrinsed and dried to prevent expo-sure of building occupants to thecleaning chemicals.

9. Water-damaged or contaminatedporous materials in the ductworkor other air handling systemcomponents should be removedand replaced.

Even when such materials arethoroughly dried, there is no way toguarantee that all microbial growthhas been eliminated.

10. After the duct system has beencleaned and restored to use, apreventive maintenance programwill prevent the recurrence ofproblems.Such a program should includeparticular attention to the use andmaintenance of adequate filters,control of moisture in the HVACsystem, and periodic inspection andcleaning of HVAC system compo-nents. (See discussion of Preven-tive Maintenance on page 36 inSection 5.)

Terminal Devices

Thermal comfort and effective contami-nant removal demand that air deliveredinto a conditioned space be properlydistributed within that space. Terminaldevices are the supply diffusers, return andexhaust grilles, and associated dampersand controls that are designed to distributeair within a space and collect it from thatspace. The number, design, and location(ceiling, wall, floor) of terminal devicesare very important. They can cause aHVAC system with adequate capacity toproduce unsatisfactory results, such asdrafts, odor transport, stagnant areas, orshort-circuiting.

Occupants who are uncomfortablebecause of distribution deficiencies (drafts,odor transport, stagnant air, or uneventemperatures) often try to compensate byadjusting or blocking the flow of air fromsupply outlets. Adjusting system flowswithout any knowledge of the properdesign frequently disrupts the propersupply of air to adjacent areas. Distribu-tion problems can also be produced if thearrangement of movable partitions,shelving, or other furnishings interfereswith airflow. Such problems often occur ifwalls are moved or added without evaluat-ing the expected impact on airflows.

Return Air Systems

In many modem buildings the above-ceiling space is utilized for the unductedpassage of return air. This type of systemapproach often reduces initial HVACsystem costs. but requires that the designer,maintenance personnel, and contractorsobey strict guidelines related to health andsafety codes (e.g., building codes) thatmust be followed for materials and devicesthat are located in the plenum. In addition,if a ceiling plenum is used for the collec-tion of return air, openings into the ceilingplenum created by the removal of ceilingtiles will disrupt airflow patterns. It is

particularly important to maintain theintegrity of the ceiling and adjacent wallsin areas that are designed to be exhausted,such as supply closets, bathrooms, andchemical storage areas.

After return air enters either a ductedreturn air grille or a ceiling plenum, it isreturned to the air handlers. Some systemsutilize return fans in addition to supplyfans in order to properly control thedistribution of air. When a supply andreturn fan are utilized, especially in a VAVsystem, their operation must be coordi-nated in order to prevent under- or over-pressurization of the occupied space oroverpressurization of the mixing plenum inthe air handler.

Exhausts, Exhaust Fans, andPressure Relief

Most buildings are required by law (e.g.,building or plumbing codes) to provide forexhaust of areas where contaminantsources are strong, such as toilet facilities,janitorial closets, cooking facilities, andparking garages. Other areas whereexhaust is frequently recommended but


Return air is frequently car-ried through non-ductedplenums. It is more difficultto control leakage of pollut-ants into or out of this typeof return air system than aducted system.

may not be legally required include:reprographics areas, graphic arts facilities,beauty salons, smoking lounges, shops,and any area where contaminants areknown to originate.

For successful confinement and exhaustof identifiable sources, the exhausted areamust be maintained at a lower overallpressure than surrounding areas. Any areathat is designed to be exhausted must alsobe isolated (disconnected) from the returnair system so that contaminants are nottransported to another area of the building.

In order to exhaust air from the build-ing, make-up air from outdoors must bebrought into the HVAC system to keep thebuilding from being run under negativepressure. This make-up air is typicallydrawn in at the mixed air plenum asdescribed earlier and distributed within thebuilding. For exhaust systems to functionproperly, the make-up air must have a clearpath to the area that is being exhausted.

It is useful to compare the total cfm ofpowered exhaust to the minimum quantityof mechanically-introduced outdoor air.To prevent operating the building undernegative pressures (and limit the amount ofunconditioned air brought into the buildingby infiltration), the amount of make-up airdrawn in at the air handler should alwaysbe slightly greater than the total amount ofrelief air, exhaust air, and air exfiltratingthrough the building shell. Excess make-up air is generally relieved at an exhaust orrelief outlet in the HVAC system, espe-cially in air economizer systems. Inaddition to reducing the effects of un-wanted infiltration, designing and operat-ing a building at slightly positive or neutralpressures will reduce the rate of entry ofsoil gases when the systems are operating.For a building to actually operate at aslight positive pressure, it must be tightlyconstructed (e.g., specified at less thanone-half air change per hour at 0.25pascals). Otherwise unwanted exfiltrationwill prevent the building from ever

134 Appendix B 148

achieving a neutral or slightly positivepressure.

Self-Contained Units

In some designs, small decentralized unitsare used to provide cooling or heating tointerior or perimeter zones. With theexception of induction units, units of thistype seldom supply outdoor air. They aretypically considered a low priority mainte-nance item. If self-contained units areoverlooked during maintenance, it is notunusual for them to become a significantsource of contaminants, especially for theoccupants located nearby.

Controls

HVAC systems can be controlled manuallyor automatically. Most systems are con-trolled by some combination of manual andautomatic controls. The control system canbe used to switch fans on and off, regulatethe temperature of air within the conditionedspace, or modulate airflow and pressures bycontrolling fan speed and damper settings.Most large buildings use automatic controls,and many have very complex and sophisti-cated systems. Regular maintenance andcalibration are required to keep controls ingood operating order. All programmabletimers and switches should have "batterybackup" to reset the controls in the event of apower failure.

Local controls such as room thermostatsmust be properly located in order tomaintain thermal comfort. Problems canresult from:

thermostats located outside of theoccupied space (e.g., in return plenum)poorly designed temperature controlzones (e.g., single zones that combineareas with very different heating orcooling loads)thermostat locations subject to drafts orto radiant heat gain or loss (e.g., exposedto direct sunlight)

thermostat locations affected by heatfrom nearby equipment

To test whether or not a thermostat isfunctioning properly, try setting it to anextreme temperature. This experiment willshow whether or not the system is respond-

ing to the signal in the thermostat, andalso provides information about how theHVAC system may perform under extremeconditions.

Boilers

Like any other part of the HVAC system, aboiler must be adequately maintained tooperate properly. However, it is particu-larly important that combustion equipmentoperate properly to avoid hazardous

conditions such as explosions or carbonmonoxide leaks, as well as to provide goodenergy efficiency. Codes in most parts ofthe country require boiler operators to beproperly trained and licensed.

Both ASME and ASHRAE have maderecommendations of how much combus-tion air is needed for fuel burning appli-ances.

Elements of boiler operation that are

particularly important to indoor air qualityand thermal comfort include:

Operation of the boiler and distributionloops at a high enough temperature to

supply adequate heat in cold weather.

Maintenance of gaskets and breeching to

prevent carbon monoxide from escapinginto the building.Maintenance of fuel lines to prevent anyleaks that could emit odors into the

building.Provision of adequate outdoor air forcombustion.

Design of the boiler combustion exhaustto prevent re-entrainment (especially

from short boiler stacks or into multi-story buildings that were added after the

boiler plant was installed).

Mt*

Modem office buildings tend to havemuch smaller capacity boilers than olderbuildings because of advances in energy

efficiency. In some buildings, the primaryheat source is waste heat recovered from

the chiller (which operates year-round tocool the core of the building).

atZzie !mom.

Cooling Towers

Maintenance of a cooling tower ensures

proper operation and keeps the cooling

tower from becoming a niche for breedingpathogenic bacteria, such as Legionella

organisms. Cooling tower water qualitymust be properly monitored and chemicaltreatments used as necessary to minimize

conditions that could support the growth ofsignificant amounts of pathogens. Propermaintenance may also entail physical

cleaning (by individuals using properprotection) to prevent sediment accumula-tion and installing drift eliminators.


It is important to determineperiodically whether theHVAC controls are correctlycalibrated. In addition, timeclocks must be checked tosee if they are properly setand running. Powerfailures frequently causetime clocks to be out ofadjustment.

FIGURE B-2: Selected Ventilation Recommendations

ApplicationOccupancy

(people/1000 ft2)Cfm/person Cfrn/ft2

Food and Beverage Dining rooms 70 20Service Cafeteria, fast food 100 20

Bars, cocktail lounges 100 30Kitchen (cooking) 20 15

Offices Office space 7 20Reception areas 60 15Conference rooms 50 20

Public Spaces Smoking lounge 70 60Elevators 1.00

Retail Stores, Sales Basement and street 30 0.30Floors, Showroom Upper floors 20 0.20Floors Malls and arcades 20 0.20

Smoking lounge . 70 60

Sports and Spectator areas 150 15Amusement Game rooms 70 25

Playing floors 30 20Ballrooms and discos 100 25

Theaters Lobbies 150 20Auditorium 150 15

Education Classroom 50 15Music rooms 50 15Libraries 20 15Auditoriums 150 15

Hotels, Motels,Resorts,Dormitories

BedroomsLiving roomsLobbies 30 15

30 cfm/room30 cfm/room

Conference rooms 50 20Assembly rooms 120 15

SOURCE: ASHRAE Standard 62-1989, Ventilation for Acceptable Air Quality

150

136 Appendix B

Water Chillers

Water chillers are frequently found in largebuilding air conditioning systems becauseof the superior performance they offer. Awater chiller must be maintained in properworking condition to perform its functionof removing the heat from the building.Chilled water supply temperatures shouldoperate in the range of 45°F or colder inorder to provide proper moisture removalduring humid weather. Piping should beinsulated to prevent condensation.

Other than thermal comfort, IAQconcerns associated with water chillersinvolve potential release of the workingfluids from the chiller system. The rupturedisk (safety release) of the system shouldbe piped to the outdoors, and refrigerantleaks should be located and repaired.Waste oils and spent refrigerant should bedisposed of properly.

ASHRAE STANDARDS ANDGUIDELINES

Standard 62-1989, "Ventilationfor Acceptable Air Quality"

ASHRAE 62-1989 is intended to assistprofessionals in the proper design ofventilation systems for buildings. Thestandard presents two procedures forventilation design: a "Ventilation Rate"procedure and an "Air Quality" procedure.

With the Ventilation Rate procedure,acceptable air quality is achieved byspecifying a given quantity and quality ofoutdoor air based upon occupant densityand space usage. Examples of the tableslisting the prescriptive amounts of outdoorair for the Ventilation Rate procedure arepresented at the end of this section.

The Air Quality procedure is a perfor-mance specification that allows acceptableair quality to be achieved within a space bycontrolling for known and specifiablecontaminants. This procedure is seldom

used because source strength is usually notknown.

Whichever procedure is utilized in thedesign, the standard states that the designcriteria and assumptions shall be docu-mented and made available to thoseresponsible for the operation and mainte-nance of the system.

Important features of ASHRAE 62-1989 include:

a definition of acceptable air qualitya discussion of ventilation effectivenessthe recommendation of the use of sourcecontrol through isolation and localexhaust of contaminantsrecommendations for the use of heatrecovery ventilationa guideline for allowable carbon dioxidelevelsappendices listing suggested possibleguidelines for common indoor pollutants

Standard 55-1981, "ThermalEnvironmental Conditions forHuman Occupancy"ASHRAE 55-1981 covers several environ-mental parameters including: temperature,radiation, humidity, and air movement.

The standard specifies thermal environ-mental conditions for the comfort ofhealthy people in normal indoor environ-ments for winter and summer conditions.It also attempts to introduce limits on thetemperature variations within a space. Inaddition to specifications for temperatureand humidity, guidelines are given for airmovement, temperature cycling, tempera-ture drift, vertical temperature difference,radiant asymmetry, and floor temperatures.Adjustment factors are described forvarious activity levels of the occupants,and different clothing levels.

Important features of this standardinclude:

a definition of acceptable thermalcomfort

r4HVAC Systems and ndoor Air Quality 137

This air washer is used toremove particles andwater-soluble gaseouscontaminants and may alsocontrol temperature andhumidity in the airstream.Such systems are subjectto severe bacterialcontamination.

a discussion of the additionalenvironmental parameters that mustbe consideredrecommendations for summer and wintercomfort zones for both temperature andrelative humiditya guideline for making adjustment foractivity levelsguidelines for making measurementsIt should be noted that space tempera-

tures above 76°F but within the summercomfort envelope have nevertheless beenassociated with IAQ complaints in offices.Note: As of summer 1991, a revisedStandard 55 was nearly ready.

Standard 52-76, "Method ofTesting Air-Cleaning DevicesUsed in General Ventilation forRemoving Particulate Matter"This standard is intended to assist profes-sionals in the evaluation of air cleaningsystems for particle removal. Two testmethods are described: the weightarrestance test and the atmospheric dustspot test. The standard discusses differ-ences in results from the weight arrestance

138 Appendix B1r ?

test and the atmospheric dust spot test.The atmospheric dust spot test is the testused to determine the "efficiency " of anair cleaner. The values obtained withthese two tests are not comparable. Forexample, a filter with a weight arrestanceof 90% may have an efficiency by theatmospheric dust spot test below 40%.

The weight arrestance test is generallyused to evaluate low efficiency filtersdesigned to remove the largest andheaviest particles; these filters are com-monly used in residential furnaces and/orair-conditioning systems or as upstreamfilters for other air cleaning devices. Forthe test, a standard synthetic dust is fedinto the air cleaner and the proportion (byweight) of the dust trapped on the filter isdetermined. Because the particles in thestandard dust are relatively large, theweight arrestance test is of limited value inassessing the removal of smaller, respi-rable-size particles from indoor air.

The atmospheric dust spot test isusually used to rate medium efficiency aircleaners. The removal rate is based on thecleaner's ability to reduce soiling of aclean paper target, an ability dependent onthe cleaner removing very fine particlesfrom the air. However, it should be notedthat this test addresses the overall effi-ciency of removal of a complex mixture ofdust, and that removal efficiencies fordifferent size particles may vary widely.Recent studies by EPA, comparingASHRAE ratings to filter efficiencies forparticles by size, have shown that efficien-cies for particles in the size range of 0.1 to1 microgram are much lower than theASHRAE rating.

Important features of this ASHRAEstandard include:

definitions of arrestance and efficiencyestablishment of a uniform comparativetesting procedure for evaluating theperformance of air cleaning devices usedin ventilation systems

establishment of a uniform reportingmethod,for performancemethods for evaluating resistance toairflow and dust-holding capacity

No comparable guidelines or standardsare currently available for use in assessingthe ability of air cleaners to remove gas-eous pollutants or radon and its progeny.

Guideline 1-1989 "Guideline forthe Commissioning of HVACSystems"

This guideline is intended to assist profes-sionals by providing procedures and meth-ods for documenting and verifying theperformance of HVAC systems so thatthey operate in conformity with the designintent. The guideline presents a format fordocumenting the occupancy requirements,design assumptions, and the design intent

for the HVAC system. It provides a for-mat for testing the system for acceptanceby the owner. In addition, the guidelineaddresses adjustments of the system tomeet actual occupancy needs within thecapacity of the system when changes inbuilding use are made andrecommissioning is warranted.

Important features of this guidelineinclude:

definition of the commissioning processdiscussion of the process involved in aproper commissioning proceduresample specification and forms for log-ging informationrecommendation for the implementationof corrective measures as warrantedguidelines for operator trainingguidelines for periodic maintenance andrecommissioning as needed

153

HVAC Systems and Indoor Air Quality 139

Appendix C:Moisture, Mold and Mildew

Molds and mildew are fungi that growon the surfaces of objects, within pores,and in deteriorated materials. They cancause discoloration and odor problems,deteriorate building materials, and lead toallergic reactions in susceptible individu-als, as well as other health problems.

The following conditions are necessaryfor mold growth to occur on surfaces:

temperature range above 40°F and below100°Fmold sporesnutrient base (most surfaces containnutrients)moisture

Human comfort constraints limit the useof temperature control. Spores are almostalways present in outdoor and indoor air,and almost all commonly used construc-tion materials and furnishings can providenutrients to support mold growth. Dirt onsurfaces provides additional nutrients.Cleaning and disinfecting with non-polluting cleaners and antimicrobial agentsprovides protection against mold growth.Other sections of this document havediscussed the importance of buildingmaintenance and proper sanitation inpreventing IAQ problems. However, it isvirtually impossible to eliminate allnutrients. Moisture control is thas animportant strategy for reducing moldgrowth.

Mold growth does not require thepresence of standing water; it can occurwhen high relative humidity or thehygroscopic properties (the tendency toabsorb and retain moisture) of buildingsurfaces allow sufficient moisture toaccumulate. Relative humidity and the

factors that govern it are often misunder-stood. This appendix is intended to givebuilding managers an understanding of thefactors that govern relative humidity, andto describe common moisture problemsand their solutions.

BACKGROUND ON RELATIVEHUMIDITY, VAPOR PRESSURE,AND CONDENSATION

Water enters buildings both as a liquid andas a gas (water vapor). Water, in its liquidform, is introduced intentionally inbathrooms, kitchens, and laundries andaccidentally by way of leaks and spills.Some of that water evaporates and joinsthe water vapor that is exhaled by buildingoccupants as they breathe or that isintroduced by humidifiers. Water vaporalso moves in and out of the building aspart of the air that is mechanically intro-duced or that infiltrates and exfiltratesthrough openings in the building shell. A

154Moisture, Mold and Mildew 141

There were complaints ofvisible water damage andmusty odors in this seniorcitizen housing complex.Investigators confirmed thatthe problem was rain entryby using an array of hosesto spray the walls withwater, while operating thebuilding under negativepressure. The test showedthat rain was entering at thejoints of the exteriorcladding, rather than atcracks around windows.

FIGURE C-1: Moisture Gain in a Building

Air leakage(carrying moisture)

by door openings andthru cracks and crevices

.e

Diffusion throughdoors, walls, partitions

Internal moisture releaseby people, showers,

wet clothes and towels

Liquid waterthru cracks

and then evaporated

Leakage aroundelectric plugs and

cracks in wall

Moisture Gain = Leakage + Diffusion + Internal

Courtesy of Dean WallaceShakun, Clayton StateCollege, Morrow, GA

lesser amount of water vapor diffuses intoand out of the building through thebuilding materials themselves. Figure C-1illustrates locations of moisture entry.

The ability of air to hold water vapordecreases as the air temperature is lowered.If a unit of air contains half of the watervapor it can hold, it is said to be at 50%relative humidity (RH). As the air cools,the relative humidity increases. If the aircontains all of the water vapor it can hold,it is at 100% RH, and the water vaporcondenses, changing from a gas to a liquid.It is possible to reach 100% RH without

142 Appendix C

changing the amount of water vapor in theair (its "vapor pressure" or "absolutehumidity"); all that is required is for the airtemperature to drop to the "dew point."

Relative humidity and temperatureoften vary within a room, while theabsolute humidity in the room air canusually be assumed to be uniform. There-fore, if one side of the room is warm andthe other side cool, the cool side of theroom has a higher RH than the warm side.

The highest RH in a room is alwaysnext to the coldest surface. This is referredas the "first condensing surface," as it will

1 5 5

FIGURE C-2: Relationship of Temperature, Relative Humidity, and Moisture in the Air

A relative humidity reading taken in a room will only give anaccurate indication of the actual amount of moisture present if atemperature reading is taken at the same time. The chart belowshows that air at 70°F and 40% RH contains approximately0.006 pounds of moisture per pound of dry air (as indicated bythe bold line), while air that is at 50°F and 40% RH containsapproximately 0.003 pounds of moisture per pound of dry air(as indicated by the dashed line). Although both are at 40% RH,the 70°F air contains roughly twice as much moisture as the50°F air.

RelativeHumidity(%RH)

Temperature(°Farenheit)

AMMIAIM,MMIANAM =IA AIWAAI

AM/I A MIIMEMA%MM M=11IMMIMPAM /111

O=MIMI%MW1=1.51/mr= MCI=`1..1111111/

GM. 111

30°F 40°F

I50°F 60°F 70°F

70°F at 40% relative humidity

50°F at 40% relative humidity

80°F 90°F

SOURCE: Adapted from Psychometric Chart from ASHRAE Fundamentals, 1981

be the location where condensation firstoccurs, if the relative humidity at thesurface reaches 100%. It is important tounderstand this when trying to understandwhy mold is growing on one patch of wallor only along the wall-ceiling joint. It islikely that the surface of the wall is coolerthan the room air because there is a void inthe insulation or because wind is blowingthrough cracks in the exterior of thebuilding.

TAKING STEPS TO REDUCEMOISTURE

100°F

Mold and mildew growth can be reducedwhere relative humidities near surfaces canbe maintained below the dew point. Thiscan be accomplished by reducing themoisture content (vapor pressure) of theair, increasing air movement at the surface,or increasing the air temperature (either thegeneral space temperature or the tempera-ture at building surfaces).

15t3Moisture, Mold and Mildew 143

110°F

.030

. 028

.026

.024

.022

.020

. 018

. 016

.014

.012

.010

.008

.006

.004

.003.002

000120°F

Above: In this building, mold andmildew spots appeared on drywalljoints on the interior walls. When thewall was cut open, mold growth wasvisible in the wall cavity and thestructural steel showed corrosion. Theproblem was caused by constructionmoisture trapped between the interiorfinish and the exterior sheathing. Thesolution was to modify the exterior wallso that moisture could vent to theoutdoors. Below: This is visualevidence of air movement through thebuilding shell. The water vapor in thewarm, humid indoor air has condensedand frozen on the exterior wall.

144 AppendixC 157

Either surface temperature or vaporpressure can be the dominant factor incausing a mold problem. A surfacetemperature-related mold problem may notrespond very well to increasing ventilation,whereas a vapor pressure-related moldproblem may not respond well to increas-ing temperatures. Understanding whichfactor dominates will help in selecting aneffective control strategy.

Consider an old, leaky, poorly insulatedbuilding. It is in a heating climate andshows evidence of mold and mildew.Since the building is leaky, its high naturalair exchange rate dilutes interior airbornemoisture levels, maintaining a low absolutehumidity during the heating season.Providing mechanical ventilation in thisbuilding in an attempt to control interiormold and mildew probably will not beeffective in this case. Increasing surfacetemperatures by insulating the exteriorwalls, and thereby reducing relativehumidities next to the wall surfaces, wouldbe a better strategy to control mold andmildew.

Reduction of surface temperature-dominated mold and mildew is bestaccomplished by increasing the surfacetemperature through either or both of thefollowing approaches:

Increase the temperature of the air nearroom surfaces either by raising thethermostat setting or by improving aircirculation so that supply air is moreeffective at heating the room surface.Decrease the heat loss from roomsurfaces either by adding insulation or byclosing cracks in the exterior wall toprevent wind-washing (air that enters awall at one exterior location and exitsanother exterior location withoutpenetrating into the building).

Vapor pressure-dominated mold andmildew can be reduced by one or more ofthe following strategies:

source control (e.g., direct venting ofmoisture-generating activities such asshowers) to the exteriordilution of moisture-laden indoor airwith outdoor air that is at a lowerabsolute humiditydehumidification

Note that dilution is only useful as acontrol strategy during heating periods,when cold outdoor air tends to contain lessmoisture. During cooling periods, outdoorair often contains as much moisture asindoor air.

IDENTIFYING AND CORRECTINGCOMMON PROBLEMS FROMMOLD AND MILDEW

Exterior Corners

Exterior comers are common locations formold and mildew growth in heatingclimates, and in poorly insulated buildingsin cooling climates. They tend to be closerto the outdoor temperature than other partsof the building surface for one or more ofthe following reasons:

poor air circulation (interior)wind-washing (exterior)low insulation levelsgreater surface area of heat loss

Sometimes mold and mildew growthcan be reduced by removing obstructionsto airflow (e.g., rearranging furniture).Buildings with forced air heating systemsand/or room ceiling fans tend to havefewer mold and mildew problems thanbuildings with less air movement, otherfactors being equal.

"Set Back" Thermostats

Set back thermostats are commonly used toreduce energy consumption during theheating season. Mold and mildew growthcan occur when building temperatures arelowered during unoccupied periods.(Maintaining a room at too low a tempera-ture can have the same effect as a set backthermostat.) Mold and mildew can often

HOW TO IDENTIFY THE CAUSE OF A MOLD ANDMILDEW PROBLEM

Mold and mildew are commonly found on the exterior wall surfaces ofcorner rooms in heating climate locations. An exposed corner room islikely to be significantly colder than adjoining rooms, so that it has ahigher relative humidity (RH) than other rooms at the same watervapor pressure. If mold and mildew growth are found in a cornerroom, then relative humidities next to the room surfaces are above70%. However, is the RH above 70% at the surfaces because the roomis too cold or because there is too much moisture present (high watervapor pressure)?

The amount of moisture in the room can be estimated by measur-ing both temperature and RH at the same location and at the sametime. Suppose there are two cases. In the first case, assume that theRH is 30% and the temperature is 70°F in the middle of the room. Thelow RH at that temperature indicates that the water vapor pressure (orabsolute humidity) is low. The high surface RH is probably due toroom surfaces that are "too cold." Temperature is the dominatingfactor, and control strategies should involve increasing the tempera-ture at cold room surfaces.

In the second case, assume that the RH is 50% and the temperatureis 70°F in the middle of the room. The higher RH at that temperatureindicates that the water vapor pressure is high and there is a relativelylarge amount of moisture in the air. The high surface RH is probablydue to air that is "too moist." Humidity is the dominating factor, andcontrol strategies should involve decreasing the moisture content ofthe indoor air.

be controlled in heating climate locationsby increasing interior temperatures duringheating periods. Unfortunately, this alsoincreases energy consumption and reducesrelative humidity in the breathing zone,which can create discomfort.

Air Conditioned Spaces

The problems of mold and mildew can beas extensive in cooling climates as inheating climates. The same principlesapply: either surfaces are too Cold,moisture levels are too high, or both.

A common example of mold growth incooling climates can be found in roomswhere conditioned "cold" air blows againstthe interior surface of an exterior wall.This condition, which may be due to poorduct design, diffuser location, or diffuserperformance, creates a cold spot at theinterior finish surfaces. A mold problemcan occur within the wall cavity as outdoorair comes in contact with the cavity side ofthe cooled interior surface. It is a particu-lar problem in rooms decorated with low

Moisture, Mold and Mildew 145

1 SR

maintenance interior finishes (e.g.,impermeable wall coverings such as vinylwallpaper) which can trap moisturebetween the interior finish and the gypsumboard. Mold growth can be rampant whenthese interior fmishes are coupled withcold spots and exterior moisture.

Possible solutions for this probleminclude:

preventing hot, humid exterior air fromcontacting the cold interior finish (i.e.,controlling the vapor pressure at thesurface)eliminating the cold spots (i.e., elevatingthe temperature of the surface) byrelocating ducts and diffusersensuring that vapor barriers, facingsealants, and insulation are properlyspecified, installed, and maintainedincreasing the room temperature to avoidovercooling

In this case, increasing temperaturedecreases energy consumption, though itcould cause comfort problems.

Thermal Bridges

Localized cooling of surfaces commonlyoccurs as a result of "thermal bridges,"elements of the building structure that arehighly conductive of heat (e.g., steel studsin exterior frame walls, uninsulatedwindow lintels, and the edges of concretefloor slabs). Dust particles sometimesmark the locations of thermal bridges,because dust tends to adhere to cold spots.

The use of insulating sheathingssignificantly reduces the impact of thermalbridges in building envelopes.

Windows

In winter, windows are typically thecoldest surfaces in a room. The interiorsurface of a window is often the firstcondensing surface in a room.

Condensation on window surfaces hashistorically been controlled by using stormwindows or "insulated glass" (e.g., double-glazed windows or selective surface gas-filled windows) to raise interior surface

146 Appendix C

temperatures. The advent of higherperformance glazing systems has led to agreater incidence of moisture problems inheating climate building enclosures,because the buildings can now be operatedat higher interior vapor pressures (moisturelevels) without visible surface condensa-tion on windows. In older buildingenclosures with less advanced glazingsystems, visible condensation on thewindows often alerted occupants to theneed for ventilation to flush out interiormoisture (so they opened the windows).

Concealed Condensation

The use of thermal insulation in wallcavities increases interior surface tempera-tures in heating climates, reducing thelikelihood of interior surface mold, mildewand condensation. However, the use ofthermal insulation also reduces the heatloss from the conditioned space into thewall cavities, decreasing the temperature inthe wall cavities and therefore increasingthe likelihood of concealed condensation.The first condensing surface in a wallcavity in a heating climate is typically theinner surface of the exterior sheathing, the"back side" of plywood or. fiberboard. Asthe insulation value is increased in the wallcavities, so does the potential for hiddencondensation.

Concealed condensation can be con-trolled by either or both of the followingstrategies:

Reducing the entry of moisture into thewall cavities (e.g., by controllinginfiltration and/or exfiltration of mois-ture-laden air); and/orElevating the temperature of the firstcondensing surface. In heating climatelocations, this change can be made byinstalling exterior insulation (assumingthat no significant wind-washing isoccurring). In cooling climate locations,this change an be made by installinginsulating sheathing to the interior of thewall framing and between the wallframing and the interior gypsum board.

159

Appendix D: Asbestos

"Asbestos" describes six naturallyoccurring fibrous minerals found in certaintypes of rock formations. When minedand processed, asbestos is typically sepa-rated into very thin fibers that are normallyinvisible to the naked eye. They mayremain in the air for many hours if re-leased from asbestos-containing material(ACM) and may be inhaled during thistime. Three specific diseases asbestosis(a fibrous scarring of the lungs), lungcancer, and mesothelioma (a cancer of thelining of the chest or abdominal cavity)have been linked to asbestos exposure. Itmay be 20 years or more after exposurebefore symptoms of these diseases appear;however, high levels of exposure can re-sult in respiratory diseases within a shorterperiod of time.

Most of the health problems resultingfrom asbestos exposure have been experi-enced by workers whose jobs exposedthem to asbestos in the air over a pro-longed period without the worker protec-tion that is now required. Asbestos fiberscan be found nearly everywhere in ourenvironment, usually at very low levels.While the risk to occupants is likely to besmall, health concerns remain, particularlyfor the custodial and maintenance workersin a building. Their jobs are likely to bringthem into proximity to ACM and maysometimes require them to disturb theACM in the performance of maintenanceactivities.

EPA estimates that "friable" (easilycrumbled) ACM can be found in an esti-mated 700,000 public and commercialbuildings. About 500,000 of those build-ings are believed to contain at least somedamaged asbestos. Significantly damagedACM is found primarily in building areas

not generally accessible to the public, suchas boiler and mechanical rooms, whereasbestos exposures generally would belimited to service and maintenance work-ers. However, if friable ACM is present inair plenums, it can be distributed through-out the building, thereby possibly exposingbuilding occupants.

When is asbestos a problem? Intact andundisturbed asbestos materials do notpose a health risk. The mere presence ofasbestos in a building does not mean thatthe health of building occupants is endan-gered. ACM which is in good condition,and is not damaged or disturbed, is notlikely to release asbestos fibers into the air.When ACM is properly managed, releaseof asbestos fibers into the air is reduced,and the risk of asbestos-related disease isthereby correspondingly reduced.

There are a number of guidelines andregulations that govern asbestos exposure.Occupational standards for preventingasbestos-related diseases are recommendedby NIOSH and promulgated by OSHA.NIOSH guidance contains RecommendedExposure Limits (RELs) and OSHAstandards set Permissible Exposure Limits(PELs). The standards also contain manyother measures, such as surveillance,medical screening, analytical methods, andmethods of control. OSHA regulationsand the EPA Worker Protection Rule alsoprovide guidance on day-to-day activitiesthat may bring workers in contact withACM. EPA National Emission Standardsfor Hazardous Air Pollutants (NESHAP)defme acceptable practices for renovationand demolition activities that involve as-bestos-containing materials. In addition,many States have set exposure standardsand other regulations concerning asbestos.

Asbestos 147 160

OSHA requires that signsbe posted around areaswhere work is being donethat involves damagedasbestos-containingmaterials. These signsmust communicate specifictypes of information.

EPA and NIOSH recommend a practicalapproach that protects public health byemphasizing that ACM in buildings shouldbe identified and appropriately managed,and that those workers who might disturbit should be properly trained and protected.

EPA AND NIOSHPOSITIONS ON ASBESTOS

In an effort to calm unwarranted fears thata number of people seem to have about themere presence of asbestos in their build-ings and to discourage the decisions bysome building owners to remove all ACMregardless of its condition, the EPA Ad-ministrator issued an Advisory to the Pub-lic on Asbestos in Buildings in 1991. Thisadvisory summarized EPA's policies forasbestos control in the presentation of thefollowing "five facts":

Although asbestos is hazardous, the riskof asbestos-related disease depends uponexposure to airborne asbestos fibers.Based upon available data, the averageairborne asbestos levels in buildingsseem to be very low. Accordingly, thehealth risk to most building occupantsalso appears to be very low.Removal is often not a building owner's

AsbestosCancer and Lung Disease Hazard

Authorized Personnel OnlyRespirators and Protective

Clothing Are Required in This Area

148 Appendix D

best course of action to reduce asbestosexposure. In fact, an improper removalcan create a dangerous situation wherenone previously existed.EPA only requires asbestos removal inorder to prevent significant public expo-sure to airborne asbestos fibers duringbuilding demolition or renovationactivities.EPA does recommend a pro-active, in-place management program wheneverasbestos-containing material isdiscovered.

NIOSH's position on asbestos exposurehas been expressed in NIOSH policy state-ments and internal reports and at OSHApublic hearings:

NIOSH recommends the goal of elimi-nating asbestos exposure in the work-place. Where exposures cannot be elimi-nated, exposures should be limited to thelowest concentration possible.NIOSH contends that there is no safeairborne fiber concentration for asbestos.NIOSH therefore believes that any de-tectable concentration of asbestos in theworkplace warrants further evaluationand, if necessary, the implementation ofmeasures to reduce exposures.NIOSH contends that there is no scien-tific basis to support differentiatinghealth risks between types of asbestosfibers for regulatory purposes.

Copies of the EPA and NIOSH policystatements and public advisories are avail-able, respectively, from those agencies.See the last section in this appendix andAppendix G for information on how toobtain them.

161

PROGRAMS FOR MANAGINGASBESTOS IN-PLACE

In some cases, an asbestos operations andmaintenance program is more appropriatethan other asbestos control strategies, in-cluding removal. Proper asbestos manage-ment is neither to rip it all out in a panic norto ignore the problem under the false pre-sumption that asbestos is "risk free."Health concerns remain, particularly forcustodial and maintenance workers.

In-place management does not mean "donothing." It means having a program toensure that the day-to-day management ofthe building is carried out in a manner thatminimizes release of asbestos fibers into theair, and that ensures that when asbestosfibers are released, either accidentally orintentionally, proper control and clean-upprocedures are implemented. Such a pro-gram may be all that is necessary to controlthe release of asbestos fibers until the as-bestos-containing material in a building isscheduled to be disturbed by renovation ordemolition activities.

The first responsibility of a buildingowner or manager is to identify asbestos-containing materials, through a building-wide inventory or on a case-by-case basis,before suspect materials are disturbed byrenovations or other actions. The AsbestosHazard Emergency Response Act(AHERA) program requires that in schoolsan inventory of asbestos materials be doneby properly accredited individuals. Startingin late 1991 or 1992, there will also be arequirement that if an inventory of asbestosmaterials is done in public and commercialbuildings, the inventory must be done byproperly, accredited individuals. In publicand commercial buildings facing majorrenovations or demolition, inspections forthe presence of ACM are required, accord-ing to the 1990 revision of the EPA Asbes-tos NESHAP. A carefully designed airmonitoring program can be used as an ad-junct to visual and physical evaluations ofthe asbestos-containing materials.

After the material is identified, the build-ing management and staff can then insti-tute controls to ensure that the day-to-daymanagement of the building is carried outin a manner that prevents or minimizes therelease of asbestos fibers into the air.These controls will ensure that when as-bestos fibers are released, either acciden-tally or intentionally, proper managementand clean-up procedures are implemented.

Another concern of EPA, NIOSH, andother Federal, State, and local agencies thatare concerned with asbestos and publichealth is to ensure proper worker trainingand protection. In the course of their dailyactivities, maintenance and service work-ers in buildings may disturb materials andthereby elevate asbestos fiber levels andasbestos exposure, especially for them-selves, if they are not properly trained andprotected. For these persons, risk may besignificantly higher than for other buildingoccupants. Proper worker training andprotection, as part of an active in-placemanagement program, can reduce anyunnecessary asbestos exposure for theseworkers and others. AHERA requires thistraining for school employees whose jobactivities may result in asbestos distur-bances.

In addition to the steps outlined above,an in-place management program willusually include notification to workers andoccupants of the existence of asbestos intheir building, periodic surveillance of thematerial, and proper recordkeeping. EPArequires all of these activities for schoolsand strongly recommends that other build-ing owners also establish comprehensiveasbestos management programs. Withoutsuch programs, asbestos materials could bedamaged or could deteriorate, which mightresult in elevated levels of airborne asbes-tos fibers. While the management costs ofall the above activities will depend uponthe amount, condition, and location of thematerials, such a program need not beexpensive.

Asbestos 149 162

WHERE TO GO FORADDITIONAL INFORMATION

For guidance on asbestos, building ownersand managers are urged to become familiarwith two EPA documents: ManagingAsbestos in Place (published in 1990 andalso known as the "Green Book") andGuidance for Controlling Asbestos-Con-taining Materials in Buildings (publishedin 1985 and also known as the "PurpleBook").

To obtain copies of the guidance publi-cations and other materials mentionedabove, or to get additional infonnation ontechnical issues, call or write:

Environmental Assistance DivisionOffice of Toxic SubstancesU.S. EPA (TS-799)401 M Street SWWashington, DC 20460Telephone (TSCA Information Hotline):202-554-1404

150 Appendix D

National Institute for OccupationalSafety and HealthTechnical Information Branch4676 Columbia ParkwayCincinnati, OH 45226Telephone: 1-800-35-NIOSH or1-800-356-4674

Contact State air pollution control or healthagencies for information on pertinent Stateactivities and regulations. To fmd an as-bestos contact in State agencies, consultthe EPA Directory of State Indoor AirContacts. For a more complete listing ofpublications concerning asbestos, refer toAppendix G.

163

Appendix E: Radon

Radon is a radioactive gas produced bythe decay of radium. It occurs naturally inalmost all soil and rock. Radon migratesthrough the soil and groundwater and canenter buildings through cracks or otheropenings in their foundations. Radon'sdecay products can cause lung cancer, andradon is second only to smoking as a causeof lung cancer in America.

Based on early data, the EPA concen-trated its radon reduction efforts on one-and tWo- family homes. Citing resultsfrom a radon survey conducted jointlywith 25 States, the EPA and the SurgeonGeneral's office issued a National HealthAdvisory that called for testing mosthomes for the presence of radon. Ex-tensive research and case studies in thefield have demonstrated practical remed-iation methods that typically reduce theindoor radon concentrations below 4 pCi/L,the current EPA action level for all occu-pied buildings.

Now that EPA technical guidance isbeing successfully used to reduce humanhealth risk in homes, the EPA is emphasiz-ing the development of radon measure-ment, mitigation, and prevention tech-niques for schools and large buildings.Preliminary data from a nationwide surveyof Federal buildings indicates that radonwill probably not be as widespread a prob-lem in large buildings as it is in homes.One of the major factors for this differenceis that multi-story buildings have propor-tionally less space in direct contact withthe earth when compared to homes.

Some of the control technologies utilizedfor homes are being studied for their ap-propriateness to other building types, in-

eluding schools and large buildings. Inaddition, new methods and technologies arebeing developed to ensure a practical andcost-effective reduction of radon in thesebuildings. As a result, published docu-ments on guidance and protocols for mea-surement and remediation of radon in largebuildings are not currently available.

This publication provides an overview ofradon issues, and should be used only asbackground information. For more infor-mation, refer to other sources of informa-tion that are specific to radon in indoor air.

BUILDING MEASUREMENT,DIAGNOSIS, AND REMEDIATION

Protocols specific to the measurement ofradon and radon progeny in large buildingsare tentatively scheduled to be published byEPA in early 1992. These large buildingmeasurement protocols can assist skilledbuilding owners or facility personnel inmaking initial screening tests for thepresence of radon. A new protocol specificto large buildings is necessary due to themajor differences in building dynamics,HVAC systems, and occupancy patternsbetween large buildings and homes, andhow these impact radon.

As part of its effort to develop wide-spread State and private sector capabilities,the EPA established a voluntary proficiencyprogram (Radon Measurement ProficiencyProgram) for radon laboratories and com-mercial measurement firms. A State Profi-ciency Report (EPA 520/1-91-014), whichgives information on specific radon mea-surement firms in your area, can be ob-tained from your State radon office or fromyour EPA Regional Office.

Radon 151 164

Three elements must be present forradon to be a problem: a radon source, apathway that allows radon to enter thebuilding, and a driving force that causesthe radon to flow through the pathway andinto the building. Preventing radon fromentering the building is always desirablecompared with mitigation after radon hasentered. The reduction of pathways anddriving forces are therefore usually thefocus of attention during diagnostic andremediation efforts.

WHERE TO GO FORADDITIONAL INFORMATION

Due to the diversity and complexity oflarge buildings, and because the researchand development of appropriate radonremediation technologies for these struc-tures are in the early phases, generalizedbuilding diagnostic and remediation meth-odologies are not yet available. For assis-tance, please contact the appropriate orga-nizations on the following list or a profes-sional engineering firm or mitigation com-pany with experience in this matter.

State Radon OfficesThere are several ways to get the name of acontact person in your State radon office orinformation about that office. You can callthe radon contact in the EPA RegionalOffice for your state or you can order theDirectory of State Indoor Air Contactsfrom the EPA Public Information Center.(See list of IAQ and radon contacts and listof EPA publications in Appendix G.)

Regional Radon Training CentersAs part of its effort to develop State andprivate sector capabilities for radon reduc-tion, the EPA has coordinated the forma-tion of four Regional Radon TrainingCenters (RRTCs). The RRTCs provide arange of radon training and proficiencyexamination courses to the public for a fee.

Eastern Regional RadonTraining CenterRutgers, The State UniversityLivingston Campus, Building 4087New Brunswick, NJ 08903-0231908-932-2582

Mid-West UniversitiesRadon ConsortiumUniversity of Minnesota1985 Buford Avenue (240)St. Paul, MN 55108-6136612-624-8747

152 Appendix E

Western Regional RadonTraining CenterGuggenheim HallColorado State UniversityFort Collins, CO 805231-800-462-7459/303-491-7742

Southern Regional RadonTraining CenterAuburn UniversityHousing Research CenterHarbert Engineering CenterAuburn University, AL 36849-5337205-844-6261

EPA Regional OfficesIf you want additional information fromEPA regarding radon, start with the EPARegional Offices. Telephone numbersfor radon information contacts are givenin the list of EPA Regional Offices inAppendix G of this publication.

EPA Radon DivisionIf information is unavailable from theabove sources, please contact the EPARadon Division at:

Radon Division (ANR-464)U.S. EPA401 M Street, SWWashington, DC 20460202-260-9605

165

Appendix F: Glossary and Acronyms

ACGIH American Conference ofGovernmental Industrial Hygienists.

ASHRAE American Society ofHeating, Refrigerating, and Air-Condition-ing Engineers.

ASTM American Society for Testingand Materials.

Air Cleaning An IAQ control strategyto remove various airborne particulatesand/or gases from the air. The three typesof air cleaning most commonly used areparticulate filtration, electrostatic precipita-tion, and gas sorption.

Air Exchange Rate Used in two ways:1) the number of times that the outdoor airreplaces the volume of air in a building perunit time, typically expressed as airchanges per hour; 2) the number of timesthat the ventilation system replaces the airwithin a room or area within the building.

Antimicrobial Agent that kills micro-bial growth. See "disinfectant," "sani-tizer," and "sterilizer."

BRI See "Building-Related Illness."

Biological Contaminants Agentsderived from or that are living organisms(e.g., viruses, bacteria, fungi, and mammaland bird antigens) that can be inhaled andcan cause many types of health effectsincluding allergic reactions, respiratorydisorders, hypersensitivity diseases, andinfectious diseases. Also referred to as"microbiologicals" or "microbials."

Breathing Zone Area of a room inwhich occupants breathe as they stand, sit,or lie down.

Building Envelope Elements of thebuilding, including all external building

materials, windows, and walls, that enclosethe internal space.

Building-Related Illness Diagnosableillness whose symptoms can be identifiedand whose cause can be directly attributedto airborne building pollutants (e.g.,Legionnaire's disease, hypersensitivitypneumonitis).

CFM Cubic feet per minute.

CO Carbon monoxide.

CO2 Carbon dioxide.

Ceiling Plenum Space below theflooring and above the suspended ceilingthat accommodates the mechanical andelectrical equipment and thai is used aspart of the air distribution system. Thespace is kept under negative pressure.

Commissioning Start-up of a buildingthat includes testing and adjusting HVAC,electrical, plumbing, and other systems toassure proper functioning and adherence todesign criteria. Commissioning alsoincludes the instruction of buildingrepresentatives in the use of the buildingsystems.

Conditioned Air Air that has beenheated, cooled, humidified, or dehumidi-fied to maintain an interior space withinthe "comfort zone." (Sometimes referred toas "tempered" air.)

Constant Air Volume System Airhandling system that provides a constantair flow while varying the temperature tomeet heating and cooling needs.

Dampers Controls that vary airflowthrough an air outlet, inlet, or duct. Adamper position may be immovable,manually adjustable, or part of an auto-mated control system.

166Glossary and Acronyms 153

Diffusers and Grilles Components ofthe ventilation system that distribute anddiffuse air to promote air circulation in theoccupied space. Diffusers supply air andgrilles return air.

Disinfectants One of three groups ofantimicrobials registered by EPA forpublic health uses. EPA considers anantimicrobial to be a disinfectant when itdestroys or irreversibly inactivatesinfectious or other undesirable organisms,but not necessarily their spores. EPAregisters three types of disinfectantproducts based upon submitted efficacydata: limited, general or broad spectrum,and hospital disinfectant.

EPA United States EnvironmentalProtection Agency.

ETS Environmental tobacco smoke.

Environmental Factors Conditionsother than indoor air contaminants thatcause stress, comfort, and/or healthproblems (e.g., humidity extremes, drafts,lack of air circulation, noise, and over-crowding).

Ergonomics Applied science thatinvestigates the impact of people'sphysical environment on their health andcomfort (e.g., determining the proper chairheight for computer operators).

Exhaust Ventilation Mechanicalremoval of air from a portion of a building(e.g., piece of equipment, room, or generalarea).

Gas Sorption Devices used to reducelevels of airborne gaseous compounds bypassing the air through materials thatextract the gases. The performance ofsolid sorbents is dependent on the airflowrate, concentration of the pollutants,presence of other gases or vapors, andother factors.

HEPA High efficiency particulatearrestance (filters).

HVAC Heating, ventilation, and air-conditioning system.

154 Appendix F 167

Hypersensitivity Diseases Diseasescharacterized by allergic responses toanimal antigens. The hypersensitivitydiseases most clearly associated withindoor air quality are asthma, rhinitis, andhypersensitivity pneumonitis. Hypersensi-tivity pneumonitis is a rare but seriousdisease that involves progressive lungdamage as long as there is exposure to thecausative agent.

IAQ Indoor air quality.

IPM Integrated pest management.

Indicator Compounds Chemicalcompounds, such as carbon dioxide, whosepresence at certain concentrations may beused to estimate certain building condi-tions (e.g., airflow, presence of sources).

MCS See "Multiple Chemical Sensitiv-ity."

MSDS Material Safety Data Sheet.

Make-up Air Air brought into abuilding from outdoors through theventilation system and that has not beenpreviously circulated through the system.

Microbiologicals See "BiologicalContaminants."

Multiple Chemical Sensitivity A termused by some people to refer to a conditionin which a person is considered to besensitive to a number of chemicals at verylow concentrations. There are a number ofviews about the existence, potential causes,and possible remedial actions regardingthis phenomenon.

NIOSH National Institute for Occupa-tional Safety and Health.

NTIS National Technical InformationService.

Negative Pressure Condition thatexists when less air is supplied to a spacethan is exhausted from the space, so the airpressure within that space is less than thatin surrounding areas.

OSHA Occupational Safety and HealthAdministration.

PELs Permissible Exposure Limits(standards set by OSHA).

PM Preventive Maintenance.

Plenum Air compartment connected toa duct or ducts.

Positive Pressure Condition that existswhen more air is supplied to a space thanis exhausted, so the air pressure within thatspace is greater than that in surroundingareas.

Psychosocial Factors Psychological,organizational, and personal stressors thatcould produce symptoms similar to poorindoor air quality.

RELs Recommended Exposure Limits(recommendations made by NIOSH).

Radiant Heat Transfer Radiant heattransfer occurs when there is a large differ-ence between the temperatures of twosurfaces that are exposed to each other, butare not touching.

Re-entrainment Situation that occurswhen the air being exhausted from a build-ing is immediately brought back into thesystem through the air intake and otheropenings in the building envelope.

SBS See "Sick Building Syndrome."

Sanitizer One of three groups of anti-microbials registered by EPA for publichealth uses. EPA considers an antimicro-bial to be a sanitizer when it reduces butdoes not necessarily eliminate all the mi-croorganisms on a treated surface. To be aregistered sanitizer, the test results for aproduct must show a reduction of at least99.9% in the number of each test microor-ganism over the parallel control.

Short-circuiting Situation that occurswhen the supply air flows to exhaust regis-ters before entering the breathing zone. Toavoid short-circuiting, the supply air mustbe delivered at a temperature and velocitythat results in mixing throughout the space.

Sick Building Syndrome Term some-times used to describe situations in which

building occupants experience acute healthand/or comfort effects that appear to belinked to time spent in a particular build-ing, but where no specific illness or causecan be identified. The complaints may belocalized in a particular room or zone, ormay be spread throughout the building.

Soil Gases Gases that enter a buildingfrom the surrounding ground (e.g., radon,volatile organics, pesticides).

Stack Effect Pressure-driven airflowproduced by convection as heated air rises,creating a positive pressure area at the topof a building and a negative pressure areaat the bottom of a building. The stackeffect can overpower the mechanical sys-tem and disrupt ventilation and circulationin a building.

Static Pressure Condition that existswhen an equal amount of air is supplied toand exhausted from a space. At staticpressure, equilibrium has been reached.

Sterilizer One of three groups of anti-microbials registered by EPA for publichealth uses. EPA considers an antimicro-bial to be a sterilizer when it destroys oreliminates all forms of bacteria, fungi,viruses, and their spores. Because sporesare considered the most difficult form of amicroorganism to destroy, EPA considersthe term sporicide to be synonymous with"sterilizer."

TLVs Threshold Limit Values (guide-lines recommended by ACGIH).

TVOCs Total volatile organic com-pounds.

Tracer Gases Compounds, such assulfur hexafluoride, which are used toidentify suspected pollutant pathways andto quantify ventilation rates. Tracer gasesmay be detected qualitatively by their odoror quantitatively by air monitoring equip-ment.

VAV Variable air volume system.

VOCs See "Volatile Organic Com-pounds."

163Glossary and Acronyms 155

Variable Air Volume System Airhandling system that conditions the air to aconstant temperature and varies the outsideairflow to ensure thermal comfort.

Ventilation Air Defined as the total air,which is a combination of the air broughtinto the system from the outdoors and theair that is being recirculated within thebuilding. Sometimes, however, used inreference only to the air brought into thesystem from the outdoors.

Volatile Organic Compounds (VOCs)Compounds that evaporate from the manyhousekeeping, maintenance, and building

169

156 Appendix F

products made with organic chemicals.These compounds are released fromproducts that are being used and that are instorage. In sufficient quantities, VOCs cancause eye, nose, and throat irritations,headaches, dizziness, visual disorders,memory impairment; some are known tocause cancer in animals; some are sus-pected of causing, or are known to cause,cancer in humans. At present, not much isknown about what health effects occur atthe levels of VOCs typicallyfound inpublic and commercial buildings.

WHO World Health Organization.

Appendix G: Resources

FEDERAL AGENCIES WITHMAJOR INDOOR AIRRESPONSIBILITY FOR PUBLICAND COMMERCIAL BUILDINGS

U.S. EnvironmentalProtection AgencyConducts a non-regulatory indoor airquality program that emphasizes research,information dissemination, technicalguidance, and training. Issues regulationsand carries out other activities that affectindoor air quality under the laws forpesticides, toxic substances, and drinkingwater.

Public Information Center(PM-211B)401 M Street, SWWashington, DC 20460202-260-2080Distributes indoor air qualitypublications.

National Pesticides TelecommunicationsNetwork National toll-free number:1-800-858-PESTIn Texas: 806-743-3091Provides information on pesticides.

TSCA Hotline Service202-554-1404Provides information on asbestos andother toxic substances.

Occupational Safety and HealthAdministrationPromulgates safety and health standards,facilitates training and consultation, andenforces regulations to ensure thatworkers are provided with safe andhealthful working conditions. (For furtherinformation contact OSHA RegionalOffices.)

National Institute forOccupational Safety and HealthConducts research, recommends standardsto the U.S. Department of Labor, andconducts training on various issuesincluding indoor air quality to promotesafe and healthful workplaces. Undertakesinvestigations at request of employees,employers, other federal agencies, andstate and local agencies to identify andmitigate workplace problems.

Requests for Field InvestigationsNIOSHHazard Evaluations and TechnicalAssistance Branch (R-9)4676 Columbia ParkwayCincinnati, OH 45226513-841-4382

Requests for Information:1-800-35-NIOSHor 1-800-356-4674

170

Resources 157

EPA Regional Offices

Address inquiries to the contacts in theEPA Regional Offices at the followingaddresses:

(CT,ME,MA,NH,RI,VT)EPA Region 1John F. Kennedy Federal BuildingBoston, MA 02203617-565-3232 (indoor air)617-565-4502 (radon)617-565-3744 (asbestos)617-565-3265 (NESHAP)

(NJ,NY,PR,VI)EPA Region 226 Federal PlazaNew York, NY 10278212-264-4410 (indoor air)212-264-4410 (radon)212-264-6671 (asbestos)212-264-6770 (NESHAP)

(DE,DC,MD,PA,VA,WV)EPA Region 3841 Chestnut BuildingPhiladelphia, PA 19107215-597-8322 (indoor air)215-597-4084 (radon)215-597-3160 (asbestos)215-597-1970 (NESHAP)

(AL,FL,GA,KY,MS,NC,SC,TN)EPA Region 4345 Court land Street, NEAtlanta, GA 30365404-347-2864 (indoor air)404-347-3907 (radon)404-347-5014 (asbestos)404-347-5014 (NESHAP)

(IL,IN,MI,MN,OH,WI)EPA Region 5230 South Dearborn StreetChicago, IL 60604Region 5 Environmental Hotline:1-800-572-2515 (IL)1-800-621-8431 (IN, MI, MN, OH, WI)312-886-7930 (outside Region 5)

158 Appendix G

(AR,LA,NM,OK,TX)EPA Region 61445 Ross AvenueDallas, TX 75202-2733214-655-7223 (indoor air)214-655-7223 (radon)214-655-7223 (asbestos)214-655-7223 (NESHAP)

(IA,KS,MO,NE)EPA Region 7726 Minnesota AvenueKansas City, KS 66101913-551-7020 (indoor air)913-551-7020 (radon)913-551-7020 (asbestos)913-551-7020 (NESHAP)

(CO,MT,ND,SD,UT,WY)EPA Region 8999 18th Street Suite 500Denver, CO 80202-2405303-293-1440 (indoor air)303-293-0988 (radon)303-293-1442 (asbestos)303-294-7611 (NESHAP)

(AZ,CA,HI,NV,AS,GU)EPA Region 975 Hawthorne Street, A-1-1San Francisco, CA 94105415-744-1133 (indoor air)415-744-1045 (radon)415-744-1136 (asbestos)415-744-1135 (NESHAP)

(AK,ID,OR,WA)EPA Region 101200 Sixth AvenueSeattle, WA 98101206-553-2589 (indoor air)206-553-7299 (radon)206-553-4762 (asbestos)206-553-1757 (NESHAP)

171

OSHA Regional Offices

(CT,ME,MA,NH,RI,VT)OSHA Region 1133 Portland Street, 1st FloorBoston, MA 02114617-565-7164

(NJ,NY,PR,VI)OSHA Region 2210 Varick Street, Room 670New York, NY 10014212-337-2376

(DE,DC,MD,PA,VA,WV)OSHA Region 3Gateway Building, Suite 21003535 Market StreetPhiladelphia, PA 19104215-596-1201

(AL,FL,GA,KY,MS,NC,SC,TN)OSHA Region 41375 Peachtree Street, NE, Suite 587Atlanta, GA 30367404-347-3573

(IL,IN,MI,MN,OH,WI)OSHA Region 5230 South Dearborn Street, Room 3244Chicago, IL 60604312-353-2220

(AR,LA,NM,OK,TX)OSHA Region 6525 Griffin Street, Room 602Dallas, TX 75202214-767-4731

(IA,KS,MO,NE)OSHA Region 7911 Walnut Street, Room 406Kansas City, MO 64106816-426-5861

(CO,MT,ND,SD,UT,WY)OSHA Region 8Federal Building, Room 15761961 Stout StreetDenver, CO 80294303-844-3061

(AZ,CA,HI,NV,AS,GU)OSHA Region 971 Stevenson Street, 4th FloorSan Francisco, CA 94105415-744-6570

(AK,ID,OR,WA)OSHA Region 101111 Third Avenue, Suite 715Seattle, WA 98101-3212206-442-5930

172

Resources 159

OTHER FEDERAL AGENCIESWITH INDOOR AIRRESPONSIBILITIES

Bonneville Power AdministrationP.O. Box 3621-RMRDPortland, OR 97208503-230-5475Provides radon-resistant constructiontechniques, source control, and removaltechnology for indoor air pollutants.

Consumer Product Safety Commission5401 Westbard AvenueBethesda, MD 202071-800-638-CPSCReviews complaints regarding the safety ofconsumer products and takes action toensure product safety.

General Services Administration18th and F Streets, NWWashington, DC 20405202-501-1464Writes indoor air quality policy for Federalbuildings. Provides proactive indoor airquality building assessments. Assessescomplaints and provides remedial action.

U.S. Department of EnergyOffice of Conservation and RenewableEnergy1000 Independence Avenue, SW, CE-43Washington, DC 20585202-586-9455Quantifies the relationship among reducedinfiltration, adequate ventilation, and ac-ceptable indoor air quality.

160 Appendix G

U.S. Department of Health and HumanServicesOffice on Smoking and HealthNational Center for Chronic,DiseasePrevention and Health PromotionCenters for Disease Control1600 Clifton Road, NEMail Stop K50Atlanta, GA 30333404-488-5705Disseminates information about the healtheffects of passive smoking and strategiesfor eliminating exposure to environmentaltobacco smoke.

Tennessee Valley AuthorityOccupational Hygiene Department328 Multipurpose BuildingMuscle Shoals, AL 35660205-386-2314Provides building surveys and assessmentsassociated with employee indoor airquality complaints.

STATE AND LOCAL AGENCIES

Your questions and concerns about indoorair problems can frequently be answeredmost readily by the government agenciesin your State or locality. Responsibilitiesfor indoor air quality issues are usuallydivided among many different agencies.You will often find that calling or writingthe agencies responsible for health or airquality control is the best way to startgetting information from your State orlocal government. The EPA and PublicHealth Foundation publication, Directoryof State Indoor Air Contacts, lists Stateagency contacts. (See publications list forinformation on ordering this publication.)

173

PRIVATE SECTOR CONTACTS

The private sector organizations that haveinformation for the public on indoor airquality issues in commercial and publicbuildings include the following:

Building ManagementAssociations

Association of Physical Plant Adminis-trators of Universities and Colleges1446 Duke StreetAlexandria, VA 22314-3492703-684-1446

Building Owners and ManagersAssociation International1201 New York Ave., NW, Suite 300Washington, DC 20005202-408-2684

Institute of Real Estate Management430 North Michigan AvenueChicago, IL 60611312-661-1930

International Council of ShoppingCenters1199 North Fairfax Street, Suite 204Alexandria, VA 22314703-549-7404

International Facilities ManagementAssociationSummit Tower, Suite 171011 Greenway PlazaHouston, TX 77046713-623-4362

National Apartment Association1111 14th Street, NW, Suite 900Washington, DC 20005202-842-4050

National Association of Industrial andOffice Parks1215 Jefferson Davis Highway, Suite 100Arlington, VA 22202703-979-3400

Professional and StandardSetting Organizations

Air and Waste Management AssociationP.O. Box 2861Pittsburgh, PA 15230412-232-1444

Air-Conditioning and RefrigerationInstitute1501 Wilson Blvd., Suite 600Arlington, VA 22209703-524-8800

American Conference of GovernmentalIndustrial Hygienists6500 Glenway Avenue, Building D-7Cincinnati, OH 45211513-661-7881

American Industrial HygieneAssociationP.O. Box 8390345 White Pond DriveAkron, OH 44320216-873-2442

American Society for Testing andMaterials1916 Race StreetPhiladelphia, PA 19103215-299-5571

American Society of Heating,Refrigerating, and Air-ConditioningEngineers1791 Tullie Circle, NEAtlanta, GA 30329404-636-8400

National Conference of States onBuilding Codes and Standards, Inc.505 Huntmar Park Drive, Suite 210Herndon, VA 22070703-437-0100

Resources 161

174

Product Manufacturers

Adhesive and Sealant Council1627 K Street, NW, Suite 1000Washington, DC 20006-1707202-452-1500

Asbestos Information Association1745 Jefferson Davis Highway, Room 509Arlington, VA 22202703-979-1150

Business Council on Indoor Air Quality1225 19th Street, Suite 300Washington, DC 20036202-775-5887

Carpet and Rug Institute310 Holiday AvenueDalton, GA 30720404-278-3176

Chemical Specialties ManufacturersAssociation1913 I Street, NWWashington, DC 20006202-872-8110

Electric Power Research InstituteP.O. Box 10412Palo Alto, CA 94303415-855-2902

Formaldehyde Institute, Inc.1330 Connecticut Avenue, NWWashington, DC 20036202-822-6757

Foundation d Wall and CeilingIndustries1600 Cameron StreetAlexandria, VA 22314-2705703-548-0374

Gas Research Institute8600 West Bryn Mawr AvenueChicago, IL 60631312-399-8304

National Paint and Coatings Association1500 Rhode Island Avenue, NWWashington, DC 20005202-462-6272

162 Appendix G 175

Thermal Insulation ManufacturersAssociation Technical ServicesAir Handling Committee1420 King StreetAlexandria, VA 22314(703) 684-0474

Building Service Associations

Air-Conditioning and RefrigerationInstitute1501 Wilson Boulevard, 6th floorArlington, VA 22209703-524-8800

Air-Conditioning Contractors ofAmerica1513 16th Street, NWWashington DC 20036202-483-9370

American Consulting Engineers Council1015 15th Street, NW, Suite 802Washington, DC 20005202-347-7474

Associated Air Balance Council1518 K Street, NWWashington, DC 20005202-737-0202

Association of Energy Engineers4025 Pleasantdale Rd., Suite 420Atlanta, GA 30340404-447-5083

Association of Specialists in Cleaningand Restoration International10830 Annapolis Junction Road, Suite 312Annapolis Junction, MD 20701301-604-4411

National Air Duct Cleaners Association1518 K Street, NW, Suite 503Washington, DC 20005202-737-2926

National Association of Power Engineers3436 Haines Way, Suite 101Falls Church, VA 22041703-845-7055

National Energy Management Institute601 North Fairfax Street, Suite 160Alexandria, VA 22314703-739-7100

National Environmental BalancingBureau1385 Piccard DriveRockville, MD 20850301-977-3698

National Pest Control Association8100 Oak StreetDunn Loring, VA 22027703-573-8330

Sheet Metal and Air ConditioningContractors National Association4201 La Fayette Center DriveChantilly, VA 22021703-803-2980

Unions

AFL-CIODepartment of Occupational Safety andHealth815 16th Street, NWWashington, DC 20006202-637-5000

American Federation of GovernmentEmployees80 F Street, NWWashington, DC 20001202-737-8700

American Federation of State, County,and Municipal Employees1625 L Street, NWWashington, DC 20036(202) 429-1215

American Federation of Teachers555 New Jersey Avenue, NWWashington, DC 20001202-879-4400

Communication Workers of America501 3rd Street, NWWashington, DC 20001202-434-1160

International Union of OperatingEngineers1125 17th Street, NWWashington, DC 20036202-429-9100

Service Employees International Union1313 L Street, NWWashington, DC 20005

Environmental/Health/Consumer Organizations

American Academy of Allergy andImmunology611 East Wells StreetMilwaukee, WI 53202414-272-6071

American Lung Associationor your local lung association1740 BroadwayNew York, NY 10019

Consumer Federation of America1424 16th Street,NW, Suite 604Washington, DC 20036

National Center for EnvironmentalHealth Strategies1100 Rural AvenueVoorhees, NJ 08043609-429-5358

National Environmental HealthAssociation720 South Colorado Blvd.South Tower, Suite 970Denver, CO 80222303-756-9090

National Foundation for the ChemicallyHypersensitiveP.O. Box 9Wrightsville Beach, NC 28480517-697-3989

Occupational Health Foundation1126 16th Street, NWWashington, DC 20036202-842-7840

Resources 1631713

PUBLICATIONS

Items marked * are available from EPAPublic Information Center (PM-211B),401 M Street, SW, Washington, DC20460. 202-260-2080.

Items marked ** are available from TSCAAssistance Hotline (TS-799), 401 MStreet, SW, Washington, DC 20460.202-554-1404.

Items marked*** are available fromNIOSH Publications Dissemination,4676 Columbia Parkway, Cincinnati, OH45202. 513-533-8287.

General Information

Cone, James E. and Michael J. Hodgson,MD, MPH. Problem Buildings: Build-ing-Associated Illness and the SickBuilding Syndrome. 1989. From theseries: "Occupational Medicine: State ofthe Art Reviews." Hanley & Belfus, Inc.,210 South 13th Street, Philadelphia, PA19107.

Godish, Thad. Indoor Air PollutionControl. 1989. Lewis Publishers, 121South Main Street, Chelsea, MI 48118.

Rajhans, G.S., Report of the Inter-ministerial Committee on Indoor AirQuality, 1988. Contact: G. Rajhans,Health and Safety Support ServicesBranch, Ministry of Labour, 400 Univer-sity Avenue, 7th Floor, Toronto, Ontario,Canada M7A 1T7.

Sheet Metal and Air ConditioningContractor's National Association, Inc.(SMACNA). Indoor Air Quality. 1988.8224 Old Courthouse Road, Vienna,Virginia 22180.

U.S. Environmental Protection Agencyand the Public Health Foundation. Direc-tory of State Indoor Air Contacts. Up-dated, 1991. *

1 154 Appendix G 177

U.S. Environmental Protection Agency.Designing for Good Indoor Air Quality:An Introduction for Design Professionals.(In progress).

U.S. Environmental Protection Agency.1988. Project Summaries: Indoor AirQuality in Public Buildings. 1988.Contains findings of research on IAQ in 10new public and commercial buildings andon building material emissions.*

U.S. Environmental Protection Agencyand the U.S. Consumer Product SafetyCommission. The Inside Story: A Guideto Indoor Air Quality. 1988. Addressesresidential indoor air quality primarily, butcontains a section on offices.*

U.S. Environmental Protection Agency.Sick Building Syndrome. Indoor AirQuality Fact Sheet #4. Revised, 1991.*

U.S. Environmental Protection Agency.Ventilation and Air Quality in Offices.Indoor Air Quality Fact Sheet #3.Revised, 1990.*

World Health Organization. Air QualityGuidelines for Europe. 1987. WHORegional Publications, European Series No.23. Available from WHO PublicationsCenter USA, 49 Sheridan Avenue, Albany,NY 12210.

Asbestos

Keyes, Dale L. and Jean Chesson. A Guideto Monitoring Airborne Asbestos inBuildings. 1989. Environmental Sciences,Inc., 105 E. Speedway Blvd., Tucson,Arizona 85705.

U.S. Department of Health and HumanServices, Public Health Service, U.S.Centers for Disease Control, NationalInstitute of Occupational Safety andHealth. Testimony of NIOSH on theOccupational Safety and HealthAdministration's Proposed Rule onOccupational Exposure to Asbestos,Tremolite, Anthophyllite, and Actinolite.

June 1984, May 1990, and January 1991.NIOSH Docket Office, C-34, 4676 Colum-bia Parkway, Cincinnati, OH 45226.

U.S. Environmental Protection Agency. AGuide to Respiratory Protection for theAsbestos Abatement Industry. 1986. EPA560/OTS 86-001. **

U.S. Environmental Protection Agency.Abatement of Asbestos-Containing PipeInsulation. 1986. Technical Bulletin No.1986-2. **

U.S. Environmental Protection Agency.Asbestos Abatement Projects: WorkerProtection. Final Rule 40 CFR. 763.February 1987. **

U.S. Environmental Protection Agency.Asbestos Ban and Phaseout Rule. 40 CFR763.160 to 763.179. Federal Register, July12, 1989. **

U.S. Environmental Protection Agency.Asbestos in Buildings: Guidance forService and Maintenance Personnel (inEnglish and Spanish). 1985. EPA 560/5-85-018. ("Custodial Pamphlet"). **

U.S. Environmental Protection Agency.Asbestos in Buildings: Simplified Sam-pling Scheme for Sulfacing Materials.1985. 560/5-85-030A. ("Pink Book"). **

U.S. Environmental Protection Agency.Guidance for Controlling Asbestos-Containing Materials in Buildings. 1985.EPA 560/5-85-024. ("Purple Book"). **

U.S. Environmental Protection Agency.Guidelines for Conducting the AHERATEM Clearance Test to DetermineCompletion of an Asbestos AbatementProject, EPA 560/5-89-001. **

U.S. Environmental Protection Agency.Managing Asbestos In Place: A BuildingOwner's Guide to Operations and Mainte-nance Programs for Asbestos-ContainingMaterials. 1990. ("Green Book").**

U.S. Environmental Protection Agency.Measuring Airborne Asbestos Following

An Abatement Action. 1985. EPA 600/4-85-049. ("Silver Book"). **

U.S. Environmental Protection Agency.National Emission Standards for Hazard-ous Air Pollutants. 40 Code of FederalRegulation 61. April 1984. **

U.S. Environmental Protection Agency.Transmission Electron MicroscopyAsbestos Laboratories: Quality AssuranceGuidelines. 1989. EPA 560/5-90-002.**

U.S. Department of Labor. OSHA Regula-tions. 29 Code of Federal Regulation1910.1001. General Industry AsbestosStandard. 29 Code of Federal Regulation1926.58. Construction Industry AsbestosStandard. June 1986; amended September1988. DOL-OSHA Docket, 200 Constitu-tion Avenue, NW, Room N 2625,Washington, DC 20210.

U.S. Department of Labor. OSHA Regula-tions. 29 Code of Federal Regulation1910.134. Respiratory Protection Stan-dard. June 1974. DOL-OSHA Docket,200 Constitution Avenue, NW, RoomN 2625, Washington, DC 20210.

Biologicals

American Council of Governmental Indus-trial Hygienists. Guidelines for the Assess-ment of Bioaerosols in the Indoor Envir-onment. 1989. 6500 Glenway Avenue,Building D-7, Cincinnati, OH 45211.

Morey, P., J. Feeley, and J. Otten.Biological Contaminants in IndoorEnvironments. 1990. American Societyfor Testing and Materials Publications,1916 Race Street, Philadelphia, PA 19103.

Building Management,Investigation, and Remediation

Bazerghi, Hani and Catherine Arnoult.Practical Manual for Good Indoor AirQuality. 1989. Quebec Association forEnergy Management. 1259 Berri Street,Suite 510, Montreal, Quebec, Canada, H2L4C7.

Resources 165 1 r",t

Hansen, Shirley J., Managing Indoor AirQuality. 1991. Fairmont Press, 700 IndianTrail, Lilburn, GA 30247.

U.S. Department of Health and HumanServices. Public Health Service. Centersfor Disease Control. National Institute forOccupational Safety and Health. IndoorAir Quality: Selected References.1989.***

U.S. Department of Health and HumanServices. Public Health Service. Centersfor Disease Control. National Institute forOccupational Safety and Health. Guidancefor Indoor Air Quality Investigations.1987.***

Weekes, Donald M. and Richard B.Gammage. The Practitioner's Approachto Indoor Air Quality Investigations.Proceedings of the Indoor Air QualityInternational Symposium. 1989. AmericanIndustrial Hygiene Association, P.O. Box8390, Akron Ohio 44320.

Environmental Tobacco Smoke

National Research Council. Environmen-tal Tobacco Smoke: Measuring Expo-sures and Assessing Health Effects. 1986.National Academy Press. 2001 WisconsinAvenue, NW, Washington, DC 20418.

U.S. Department of Health and HumanServices. Public Health Service. Officeon Smoking and Health. The HealthConsequences of Involuntary Smoking,A Report of the Surgeon GeneraL 1986.1660 Clifton Road, NE (Mail Stop K50)Atlanta, GA 30333.

U.S. Department of Health and HumanServices. Public Health Service. Centersfor Disease Control. National Institute forOccupational Safety and Health. CurrentIntelligence Bulletin 54: EnvironmentalTobacco Smoke in the WorkplaceLung Cancer and Other Health Effects.DHHS (NIOSH) Publication No. 91-108.199 1 .***

166 Appendix G

U.S. Department of Health and HumanServices. National Cancer Institute.Office of Cancer Communications. Aseries of one-page information sheets onall.aspects of smoking in the workplace.For copies, call 1-800-4-CANCER.

U.S. Environmental Protection Agency.Environmental Tobacco Smoke. IndoorAir Quality Fact Sheet #5. 1989.*

U.S. Environmental Protection Agency.Environmental Tobacco Smoke: A Guideto the Development of Effective SmokingPolicies. (In progress.) *

U.S. Environmental Protection Agency.Health Effects of Passive Smoking:Assessment of Lung Cancer in Adults andRespiratory Disorders in Children. (Inprogress.) *

PCBs

U.S. Department of Health and HumanServices. Public Health Service. Centersfor Disease Control. National Institute forOccupational Safety and Health. CurrentIntelligence Bulletin 45: PolychlorinatedBiphenyls Potential Health Hazardsfrom Electrical Equipment Fires orFailures. DHHS (NIOSH) PublicationNo. 86-111. 1977. Available from theNational Technical Information Service,5285 Port Royal Road, Springfield, VA22161.

U.S. Department of Health and HumanServices. Public Health Service. Centersfor Disease Control. National Institute forOccupational Safety and Health. ARecommended Standard for OccupationalExposure to Polychlorinated Biphenyls.DHHS (NIOSH) Publication No. 77-225.1977. Available from the NationalTechnical Information Service, 5285 PortRoyal Road, Springfield, VA 22161.

U.S. Environmental Protection Agency.Transformers and the Risk of Fire: AGuide for Building Owners. 1986. OPA/86-001. **

179

Radon

U.S. Environmental Protection Agency.State Proficiency Report. 1991. EPA520/1-91-014. Available from Stateradon offices. List of laboratories thathave demonstrated competence in radonmeasurement analysis.

Standards and Guidelines

American Conference of GovernmentIndustrial Hygienists. Threshold LimitValues and Biological Exposure Indices.1990-1991. 6500 Glenway Avenue,Building D-7, Cincinnati, OH 45211.

U.S. Department of Health and HumanServices. Public Health Service. Centersfor Disease Control. National Institute forOccupational Safety and Health. NIOSHRecommendations for OccupationalSafety and Health. Compendium ofPolicy Documents and Statements.DHHS (NIOSH) Publications 91-109.1991.***

U.S. Department of Labor. OSHARegulations. 29 CFR Part 1910.1000.OSHA Standards for Air Contaminants.Available from the U.S. GovernmentPrinting Office, Washington, DC 20402.202-783-3238. Additional healthstandards for some specific air contami-nants are also available in Subpart Z.

VentilationfThermal Comfort

Brief descriptions of the ASHRAEstandards listed below are included inAppendix B. ASHRAE materials areavailable from their Publication SalesDepartment, 1791 Tullie Circle, NE,Atlanta, GA 30329. 404-636-8400.

ASHRAE Guideline 1-1989. Guidelinefor the Commissioning of HVACSystems. 1989.

ASHRAE Journal. October 1989 issue.Several articles describing ASHRAEStandard 62-1989.

ASHRAE Standard 52-76. Method ofTesting Air-Cleaning Devices Used inGeneral Ventilation for RemovingParticulate Matter. 1976.

ASHRAE Standard 55-1981. ThermalEnvironmental Conditions for HumanOccupancy. 1981.

ASHRAE Standard 62-1989. Ventila-tion for Acceptable Indoor Air Quality.1989.

National Conference of States on BuildingCodes and Standards, Inc. The VentilationDirectory. 505 Huntmar Park Drive, Suite210, Herndon, VA 22070. 703-481-2020.Summarizes natural, mechanical, andexhaust ventilation requirements of themodel codes, ASHRAE standards, andunique State codes.

TRAINING

American Industrial Hygiene Associa-tion (AIHA). P.O. Box 8390, 345 WhitePond Drive, Akron, OH 44320. 216-873-2442. Sponsors indoor air quality coursesin conjunction with meetings for A1HAmembers only.

American Society of Heating, Refriger-ating, and Air-Conditioning Engineers(ASHRAE). 1791 Tullie Circle NE,Atlanta, GA 30329. 404-636-8400.Sponsors professional developmentseminars on indoor air quality.

NIOSH Division of Training andManpower Development and NIOSH-funded Educational Resource Centers.4676 Columbia Parkway, Cincinnati, OH45226. 513-8221. Provide training tooccupational safety and health profession-als and paraprofessionals.

OSHA Training Institute. 155 TimesDrive, Des Plaines, IL 60018. 708-297-4913. Provides courses to assist healthand safety professionals in evaluatingindoor air quality.

Resources 1.143 0

Building Air QualityA

BLANK FORMS \

181 Printed on Recycled Paper

Indoor Air Quality Forms

his section of the document is a collec-tion of the forms that appear or are men-tioned in the text. Consider making copiesof the forms, blocking out the page infor-mation at the bottom of the copies, and thenreproducing these copies for use in yourbuilding. Some or all of them may requireadaptation to meet your specific needs.Blank formatted sheets are included forpreparing your own HVAC Checklist andPollutant and Source Inventory.

The forms appear in the followingsequence:

IAQ Management Checklist (4 pages): forkeeping track of the elements of the IAQprofile and IAQ management plan

Pollutant Pathway Record For IAQProfiles: for identifying areas in whichnegative or positive pressures should bemaintained

ZonelRoom Record: for recording infor-mation on a room-by-room basis on thetopics of room use, ventilation, and occu-pant population.

Ventilation Worksheet: to be used in con-junction with the Zone/Room Record whencalculating quantities of outdoor air that arebeing supplied to individual zones or rooms

IAQ Complaint Form: to be filled out bythe complainant or by a staff person whoreceives information from the complainant

Incident Log: for keeping track of eachIAQ complaint or problem and how it ishandled

Occupant Interview (2 pages): for record-ing the observations of building occupantsin relation to their symptoms and condi-tions in the building

Occupant Diary: for recording incidentsof symptoms and associated observationsas they occur

Log of Activities and System Operation:for recording activities and equipmentoperating schedules as they occur

HVAC Checklist - Short Form (4 pages):to be used as a short form for investigatingan IAQ problem, or for periodic inspec-tions of the HVAC system. Duplicatepages 2 through 4 for each large air han-dling unit.

HVAC Checklist - Long Form (14 pages,followed by one blank formatted sheet):to be used for detailed inspections of theHVAC system or as a long form for inves-tigating an IAQ problem. Duplicate pages1 through 11 for each large air handlingunit.

Pollutant Pathway Form ForInvestigations: to be used in conjunctionwith a floor plan of the building.

Pollutant and Source Inventory (6 pages,followed by one blank formatted sheet):to be used as a general checklist of poten-tial indoor and outdoor pollutant sources.

Chemical Inventory: for recordinginformation about chemicals stored orused within the building

Hypothesis Form: to be used forsummarizing what has been learned duringthe building investigation; a tool to helpthe investigator collect his or her thoughts.

182

Indoor Air Quality Forms 169

IAQ Management Checklist Page 1 of 4

Building Name: Date.

Address.

Completed by (name/title).

Use this checklist to make sure that you have included all necessary elements in your !AO profile andIAQ management plan. Sections 4 and 5 discuss the development of the IAQ profile and IAQ management plan.

Item

Date begunor completed(as applicable)

Responsible person(name, telephone)

Location("NA" if the item is not

applicable to this building)

IACI PROFILE

Collect and Review ExistingRecords

HVAC design data, operatinginstructions, and manuals

HVAC maintenance and calibrationrecords, testing and balancing reports

Inventory of locations where occu-pancy, equipment, or building usehas changed


Conduct a WalkthroughInspection of the Building

List of responsible staff and/orcontractors, evidence of training,and job descriptions

Identification of areas wherepositive or negative pressureshould be maintained

Record of locations that needmonitoring or correction

Collect Detailed Information

Inventory of HVAC systemcomponents needing repair,adjustment, or replacement

Record of control settings andoperating schedules 1 8 3



Rem





Plan showing airflow directions orpressure differentials in significantareas

Inventory of significant pollutantsources and their locations

MSDSs for supplies andhazardous substances that are storedor used in the building

Zone/Room Record

!AO MANAGEMENT PLAN

Select IAG Manager

Review !AG Profile

Assign Staff Responsibilities/Train Staff

Facilities Operation and Maintenance

confirm that equipment operatingschedules are appropriate

confirm appropriate pressurerelationships between buildingusage areas

compare ventilation quantities todesign, codes, and ASHRAE 62-1989

schedule equipment inspectionsper preventive maintenance plan orrecommended maintenance schedule

modify and use HVAC Checklist(s);update as equipment is added,removed, or replaced

schedule maintenance activities toavoid creating IAQ problems

172 Indoor Air Quality Forms 1 8 4


Item



Location("NW if the item is not


review MSDSs for supplies; requestadditional information as needed

consider using alarms or otherdevices to signal need for HVACmaintenance (e.g., clogged filters)

Housekeeping

evaluate cleaning schedules andprocedures; modify if necessary

review MSDSs for products in use;buy different products if necessary

confirm proper use and storage ofmaterials

review trash disposal procedures;modify if necessary

,

Shipping and Receiving

review loading dock procedures(Note: If air intake is located nearby,take precautions to prevent intake ofexhaust fumes.)

check pressure relationships aroundloading dock

Pest Control

consider adopting IPM methods

obtain and review MSDSs; reviewhandling and storage

review pest control schedules andprocedures

review ventilation used duringpesticide application

185Indoor Air Quality Forms 173

lACI Management Checklist Page 4 of 4

Item





Occupant Relations .

establish health and safetycommittee or joint tenant/management IAQ taskforce

review procedures for respondingto complaints; modify if necessary

review lease provisions; modifyif necessary

Renovation, Redecorating,Remodeling

discuss IAQ concerns witharchitects, engineers, contractors,and other professionals

obtain MSDSs; use materialsand procedures that minimizeIAQ problems

.

schedule work to minimizeIAQ problems

arrange ventilation to isolatework areas

use installation proceduresthat minimize emissions fromnew furnishings

Smoking

eliminate smoking in the building

if smoking areas are designated,provide adequate ventilation andmaintain under negative pressure

work with occupants to developappropriate non-smoking policies,including implementationof smoking cessation programs

.

186174 Indoor Air Quality Forms

Pollutant Pathway Record ForIAQ ProfilesThis form should be used in combination with a floor plan such as a fire evacuation plan.

Building Name: File Number:

Address:

Completed by: Title: Date:

Sections 2, 4 and 6 discuss pollutant pathways and driving forces.

Building areas that contain contaminant sources (e.g., bathrooms, food preparation areas, smoking lounges, printrooms, and art rooms) should be maintained under negative pressure relative to surrounding areas. Building areasthat need to be protected from the infiltration of contaminants (e.g., hallways in multi-family dwellings, computerrooms, and lobbies) should be maintained under positive pressure relative to the outdoors and relative to surroundingareas.

List the building areas in which pressure relationships should be controlled. As you inspect the building, put a Y or Nin the "Needs Attention" column to show whether the desired air pressure relationship is present. Mark the floor planwith arrows, plus signs (+) and minus signs (-) to show the airflow patterns you observe using chemical smoke or amicromanometer.

Building areas that appear isolated from each other may be connected by airflow passages such as air distributionzones, utility tunnels or chases, party walls, spaces above suspended ceilings (whether or not those spaces areserving as air plenums), elevator shafts, and crawlspaces. If you are aware of pathways connecting the room toidentified pollutant sources (e.g., items of equipment, chemical storage areas, bathrooms), it may be helpful to recordthem in the "Comments" column, on the floor plan, or both.

Building Area(zone, room)

Use

Intended Pressure NeedsAttention?

(11/N)

CommentsPositive(+)

Negative(-)

1 87Indoor Air Quality Forms 175

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Ventilation WorksheetBuilding Name: File Number:

Address:

Completed by (name): Date:

This worksheet is designed for use with the Zone/Room Record. Appendix A provides guidance on methods ofestimating the amount of ventilation (outdoor) air being introduced by a particular air handling unit. Appendix Bdiscusses the ventilation recommendations of ASHRAE Standard 62-1989, which was developed for the purpose ofpreventing indoor air quality problems. Formulas are given below for calculating outdoor air quantities using thermalor CO, information.

The equation for calculating outdoor air quantities using thermal measurements is:

Outdoor air (in percent) = T return air T mixed air X 100T return air - T outdoor air

Where: T = temperature in degrees Fahrenheit

The equation for calculating outdoor quantities using carbon dioxide measurements is:

Outdoor air (in percent) = Cs Cr100

Co CrWhere: Cs= ppm of carbon dioxide in the supply air (if measured in a room), or

Cs= ppm of carbon dioxide in the mixed air (if measured at an air handler)Cr= ppm of carbon dioxide in the return airCs= ppm of carbon dioxide in the outdoor air

Use the table below to estimate the ventilation rate in any room or zone. Note: ASHRAE 62-1989 generally statesventilation (outdoor air) requirements on an occupancy basis; for a few types of spaces, however, requirements aregiven on a floor area basis. Therefore, this table provides a process of calculating ventilation (outdoor air) on eitheran occupancy or floor area basis.

Zone/Room Percent ofOutdoor Air

A

Total AirSupplied toZone/Room

(cfm)

B

Peak Occupancy(number of people)

orFloor Area

(square feet)

C

D= B

Total AirSupplied Per Person

(or per square foot area)

D

E = (Ax100) x DOutdoor air

Supplied Per Person(or per square foot area)

E


Indoor Air Quality Complaint FormThis form can be filled out by the building occupant or by a member of the building staff.

Occupant Name: Date:

Department/Location in Building: Phone:

Completed by: Title: Phone:

This form should be used if your complaint may be related to indoor air quality. Indoor air quality problems includeconcerns with temperature control, ventilation, and air pollutants. Your observations can help to resolve the problemas quickly as possible. Please use the space below to describe the nature of the complaint and any potential causes.

We may need to contact you to discuss your complaint. What is the best time to reach you?

So that we can respond promptly, please return this form to:IAQ Manager or Contact Person

Room, Building, Mail Code

OFFICE USE ONLY

File Number: Received By: Date Received.


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0 Occupant Interview Page 1 of 2


Address:

Occupant Name: Work Location:

Completed by: Title: Date:

Section 4 discusses collecting and interpreting information from occupants.

SYMPTOM PATrERNSWhat kind of symptoms or discomfort are you experiencing?

Are you aware of other people with similar symptoms or concerns? Yes No

If so, what are their names and locations?

Do you have any health conditions that may make you particularly susceptible to environmental problems?

0 contact lenses 0 chronic cardiovascular disease

0 allergies 0 chronic respiratory disease

0 chronic neurological problems

TIMING PATrERNS

When did your symptoms start?

When are they generally worst?

Do they go away? If so, when?

0 undergoing chemotherapy or radiation therapy

0 immune system suppressed by disease orother causes

Have you noticed any other events (such as weather events, temperature or humiditychanges, or activities in thebuilding) that tend to occur around the same time as your symptoms?

194


Occupant InterviewSPATIAL PATTERNS

Where are you when you experience symptoms or discomfort?

Where do you spend most of your time in the building?

Page 2 of 2

ADDITIONAL INFORMATIONDo you have any observations about building conditions that might need attention or might help explain yoursymptoms (e.g., temperature, humidity, drafts, stagnant air, odors)?

Have you sought medical attention for your symptoms?

Do you have any other comments?

105


Occupant Diary

Occupant Name: Title: Phone:

Location: File Number :

On the form below, please record each occasion when you experience a symptom of ill-health or discomfort that youthink may be linked to an environmental condition in this building.

It is important that you record the time and date and your location within the building as accurately as possible,because that will help to identify conditions (e.g., equipment operation) that may be associated with your problem.Also, please try to describe the severity of your symptoms (e.g., mild, severe) and their duration (the length of time thatthey persist). Any other observations that you think may help in identifying the cause of the problem should be notedin the "Comments" column. Feel free to attach additional pages or use more than one line for each event if you need

more room to record your observations.

Section 6 discusses collecting and interpreting occupant information.

Time/Date Location Symptom Severity/Duration Comments

196Indoor Air Quality Fornis 187

Log of Activities and System Operation

Building Name: Address: File Number :

Completed by: Title: Phone:

On the form below, please record your observations of the HVAC system operation, maintenance activities, and anyother information that you think might be helpful in identifying the cause of 1AQ complaints in this building. Pleasereport any other observations (e.g., weather, other associated events) that you think may be important as well.

Feel free to attach additional pages or use more than one line for each event.

Equipment and activities of particular interest:

Air Handler(s):

Exhaust Fan(s):

Other Equipment or Activities:

Date/Time, Day of Week Equipment Item/Activity Observations/Comments


HVAC Checklist - Short Form Page 1 of 4

Building Name: Address:

Completed by: Date: File Number:

Sections 2, 4 and 6 and Appendix 8 discuss the relationships between the HVAC system and indoor air quality.

MECHANICAL ROOM

Clean and dry? Stored refuse or chemicals?

a Describe items in need of attention

MAJOR MECHANICAL EQUIPMENT

Preventive maintenance (PM) plan in use?

Control System

Type

System operation

Date of last calibration

Boiler

Rated Btu input Condition

Combustion air: is there at least one square inch free area per 2,000 Btu input?

Fuel or combustion odors

Cooling Tower

Clean? no leaks or overflow? Slime or algae growth?

Eliminator performance

Biocide treatment working? (list type of biocide)

Spill containment plan implemented? Dirt separator working?

Chillers

Refrigerant leaks?

Evidence of condensation problems?

Waste oil and refrigerant properly stored and disposed ofi

191 Indoor Air Quality Forms .




AIR HANDLING UNIT

Unit identification Area served

Outdoor Air Intake, Mixing Plenum, and Dampers

Outdoor air intake location

Nearby contaminant sources? (describe)

Bird screen in place and unobstructed?

Design total cfm outdoor air (0.A.) cfm date last tested and balanced

Minimum % O.A. (damper setting) Minimum cfm O.A. (total cfm x minimum % O.A.)100

Current O.A. damper setting (date, time, and HVAC operating mode)

Damper control sequence (describe)

Condition of dampers and controls (note date)

Fans

Control sequence

Condition (note date)

Indicated temperatures supply air mixed air return air outdoor air

Actual temperatures supply air mixed air return air outdoor air

Coils

Heating fluid discharge temperature AT cooling fluid discharge temperature AT

Controls (describe)

Condition (note date)

Humidifier

Type If biocide is used, note type

Condition (no overflow, drains trapped, all nozzles working?)

No slime, visible growth, or mineral deposits?





DISTRIBUTION SYSTEM

Zone/Room

SystemType

Supply Air Return Air Power Exhaust

ducted/unducted

cfm ducted/unducted

cfm cfm control serves(e.g. toilet)

Condition of distribution system and terminal equipment (note locations of problems)

Adequate access for maintenance?

Ducts and coils clean and obstructed?

Air paths unobstructed? supply return transfer exhaust make-up

Note locations of blocked air paths, diffusers, or grilles

Any unintentional openings into plenums?

Controls operating properly?

Air volume correct?

Drain pans clean? Any visible growth or odors?

Fitters

Location Type/Rating Size Date Last Changed Condition (give date)




Completed by: Date:

OCCUPIED SPACE

Thermostat types

Pile Number:

Zone/Room

ThermostatLocation

What DoesThermostat

Control?(e.g., radiator,

AHU-3)

Setpoints MeasuredTemperature

Day/Time

Summer Winter

Humidistat/Dehumidistat types

Zone/Room

Humidistat/Dehumidistat

Location

What Does ItControl?

Setpoints(%RH)

MeasuredTemperature

Day/Time

Potential problems (note location)

Thermal comfort or air circulation problems (drafts, obstructed airflow, stagnant air, overcrowding, poorthermostat location)

Malfunctioning equipment

Major sources of odors or contaminants (e.g., poor sanitation, incompatible uses of space)

Indoor Air Quality Forms

HVAC Checklist - Long Form Page 1 of 14

Building: File Number:

Completed by: Title: Date Checked:

Appendix B discusses HVAC system components in relation to indoor air quality.

Component OK

NeedsAttention

NotApplicable Comments

Outside Air Intake

Location

Open during occupied hours?

Unobstructed?

Standing water, bird droppingsin vicinity?

Odors from outdoors?(describe)

Carryover of exhaust heat?

Cooling tower within 25 feet?

Exhaust outlet within 25 feet?

Trash compactor within 25 feet?

Near parking facility, busy road,loading dock?

Bird Screen

Unobstructed?

General condition?

Size of mesh? (1/2" minimum)

Outside Air Dampers

Operation acceptable?

Seal when closed?2 0 2





Component OK

NeedsAttention


Actuators operational?

Outdoor Air (0.A.) Quantity(Check against applicable codesand ASHRAE 62-1989.)

Minimum % O.A.

Measured % O.A.Note day, time, HVAC operatingmode under "Comments"

Maximum % O.A.

Is minimum O.A. a separate damper?

For VAV systems: is O.A. increasedas total system air-flow is reduced?

Mixing Plenum

Clean?

Floor drain trapped?

Airtightness

of outside air dampers

of return air dampers

of exhaust air dampers

All damper motors connected?

All damper motors operational?

Air mixers or opposed blades?





Component OKNeeds

AttentionNot

Applicable Comments

Mixed air temperature controlsetting oF

Freeze stat setting oF

Is mixing plenum under negativepressure? Note: If it is underpositive pressure, outdoor airmay not be entering.

Filters

Type

Complete coverage?(i.e., no bypassing)

Correct pressure drop? (Compare tomanufacturer's recommendations.)

Contaminants visible?

Odor noticeable?

Spray Humidifiers orAir Washers

Humidifier type

All nozzles working?

Complete coil coverage?

Pans clean, no overflow?

Drains trapped?

Biocide treatment working?Note: Is MSDS on file?

Spill contaminant system in place?





Component OKNeeds

AttentionNot

Applicable Comments

Face and Bypass Dampers

Damper operation correct?

Damper motors operational?

Cooling Coil

Inspection access?

Clean?

Supply water temp oF

Water carryover?

Any indication of condensationproblems?

Condensate Drip Pans

Accessible to inspect and clean?

Clean, no residue?

No standing water, no leaks?

Noticeable odor?

Visible growth (e.g., slime)?

Drains and traps clear, working?

Trapped to air gap?

Water overflow?

2 0 5198 Indoor Air Quality Forms




Component OKNeeds

AttentionNot

Applicable Comments

Mist Eliminators

Clean, straight, no carryover?

Supply Fan Chambers

Clean?

No trash or storage?

Floor drain traps are wet or sealed?

No air leaks?

Doors close tightly?

Supply Fans

Location

Fan blades clean?

Belt guards installed?

Proper belt tension?

Excess vibration?

Corrosion problems?

Controls operational, calibrated?

206





Component OKNeeds

AttentionNot

Applicable Comments

Control sequence conformsto design/specifications?(describe changes)

No pneumatic leaks?

Heating Coil

Inspection access?

Clean?

Control sequence conforms todesign/specifications?(describe changes)

Supply water temp. oF

Discharge thermostat?(air temp. setting °F)

Reheat Coils

Clean?

Obstructed?

Operational?

Steam Humidifier

Humidifier type

Treated boiler water?

Standing water?9 n r;





Component OKNeeds

AttentionNot

Applicable Comments

Visible growth?

Mineral deposits?

Control setpoint oF

High limit setpoint oF

Duct liner within 12 feet? (If so,check for dirt, mold growth.)

Supply Ductwork

Clean?

Sealed, no leaks, tight connections?

Fire dampers open?

Access doors closed?

Lined ducts?

Flex duct connected, no tears?

Light troffer supply?

Balanced within 3-5 years?

Balanced after recent renovations?

Short circuiting or other airdistribution problems? Notelocation(s)

Pressurized CeilingSupply Plenum

No unintentional openings?

All ceiling tiles in place?





Component OKNeeds

AttentionNot

Applicable Comments

Barrier paper correctly placed andin good condition?

Proper layout for air distribution?

Supply diffusers open?

Supply diffusers balanced?

Balancing capability?

Noticeable flow of air?

Short circuiting or other airdistribution problems? Notelocation(s) in''Comments"

Terminal Equipment (supply)_

Housing interiors clean andunobstructed?

Controls working?

Delivering rated volume?

Balanced within 3-5 years?.

Filters in place?

Condensate pans clean, drainfreely?

VAV Box

Minimum stops %

Minimum outside air %(from page 2 of this form)

Minimum airflow cfm

Minimum outside air cfm





Component OKNeeds

AttentionNot

Applicable Comments

Supply setpoint °F (summer)

°F (winter)

Thermostats

Type

Properly located? .

Working?

Setpoints °F (summer)

°F (winter)

Space temperature oF

Humidity Sensor

Humidistat setpoints % RH

Dehumidistat setpoints % RH

Actual RH %

Room Partitions

Gap allowing airflow at top?

Gap allowing airflow at bottom?

Supply and return each room?





Component OKNeeds

AttentionNot

Applicable Comments

Stairwells

Doors close and latch?

No openings allowinguncontrolled airflow?

Clean, dry?

No noticeable odors?

Return Air Plenum

Tiles in place?

No unintentional openings?

Return grilles?

Balancing capability?

Noticeable flow of air?

Transfer grilles?

Fire dampers open?

Ducted Returns

Balanced within 3-5 years?

Unobstructed grilles?

Unobstructed return air path?

Return Fan Chambers

Clean and no trash or storage?

No standing water?

Floor drain traps are wet or sealed?n 4, 1





Component OKNeeds

AttentionNot

Applicable Comments

No air leaks?

Doors close tightly, kept closed?

Return Fans

Location

Fan blades clean?

Belt guards installed?

Proper belt tension?

Excess vibration?

Corrosion problems?

Controls working, calibrated?

Control sequence conforms todesign/specifications?(describe changes)

Exhaust Fans

Central?

Distributed (locations)

Operational?

Controls operational?

Toilet exhaust only?

Gravity relief?9 1 9





Component OKNeeds

AttentionNot

Applicable Comments

Total powered exhaust cfm

Make-up air sufficient?

Toilet Exhausts

Fans working occupied hours?

Registers open, clear?

Make-up air path adequate?

Volume according to code?

Floor drain traps wet or sealable?

Bathrooms run slightly negativerelative to building?

Smoking Lounge Exhaust

Room runs negative relative tobuilding?

Print Room Exhaust

Room runs negative relativeto building?

Garage Ventilation

Operates according to codes?

Fans, controls, dampers all operate?

21 3206 Indoor Air Quality Forms




Component OK

NeedsAttention


Garage slightly negative relativeto building?

Doors to building close tightly?

Vestibule entrance to buildingfrom garage?

Mechanical Rooms

General condition?

Controls operational?

Pneumatic controls:

compressor operational?

air dryer operational?

Electric controls? Operational?

EMS (Energy Management System)or DDC (Direct Digital Control):

operator on site?

controlled off-site?

are fans cycled "off whilebuilding is occupied?

is chiller reset to shed load?

Preventive Maintenance

Spare parts inventoried?

Spare air filters?

Control drawing posted?





Component OKNeeds

AttentionNot

Applicable Comments

PM (Preventive Maintenance)schedule available?

PM followed?

Boilers

Flues, breeching tight?

Purge cycle working?

Door gaskets tight?

Fuel system tight, no leaks?

Combustion air: at least 1 squareinch free area per 2000 Btu input?

Cooling Tower

Sump clean?

No leaks, no overflow?

Eliminators working, no carryover?

No slime or algae?

Biocide treatment working?

Dirt separator working?

Chillers

No refrigerant leaks?

Purge cycle normal?

Waste oil, refrigerant properlydisposed of and spare refrigerantproperly stored?

Condensation/problems?t-1 1 1--,


HVAC Checklist - Long Form Page of



Component OK

NeedsAttention


216


Pollutant Pathway Form For Investigations

Building Name: SFile Number:

Address: Completed by:

This form should be used in combination with a floor plan such as a fire evacuation plan.

Building areas that appear isolated from each other may be connected by airflow passages such as air distribution zones,utility tunnels or chases, party walls, spaces above suspended ceilings (whether or not those spaces are serving as air

plenums), elevator shafts, and crawl spaces.

Describe the complaint area in the space below and mark it on your floor plan. Then list rooms or zones connected to thecomplaint area by airflow pathways. Use the form to record the direction of air flow between the complaint area and theconnected rooms/zones, including the date and time. (Airflow patterns generally change over time). Mark the floor planwith arrows or plus (+) and minus (-) signs to map out the airflow patterns you observe, using chemical smoke or amicromanometer. The "Comments" column can be used to note pollutant sources that merit further attention.

Rooms or zones included in the complaint area:

Sections 2, 4 and 6 discuss pollutant pathways and driving forces.

Rooms or ZonesConnected to theComplaint Area

By Pathways

Use

Pressure Relative toComplaint Area

Comments (e.g., potential pollutant sources)

+/- date/time


Pollutant and Source Inventory Page 1 of 6



Using the list of potential source categories below, record any indications of contamination or suspected pollutantsthat may require further investigation or treatment. Sources of contamination may be constant or intermittent or maybe linked to single, unrepeated events. For intermittent sources, try to indicate the time of peak activity or contami-nant production, including correlations with weather (e.g., wind direction).

Sections 2, 4 and 6 discuss pollutant sources. Appendix A provides guidance on common measurements.

Source Category CheckedNeeds

Attention Location Comments -

SOURCES OUTSIDE BUILDING

Contaminated Outdoor Air

Pollen, dust

Industrial contaminants .

General vehicular contaminants

Emissions from Nearby Sources

Vehicle exhaust (parking areas,loading docks, roads)

Dumpsters

Re-entrained exhaust

Debris near outside air intake

Soil Gas

Radon

Leaking underground tanks

Sewage smells

Pesticides







Attention Location Comments

Moisture or Standing Water

Rooftop

Crawlspace

EQUIPMENT

HVAC System Equipment

Combustion gases -

Dust, dirt, or microbial growthin ducts

Microbial growth in drip pans,chillers, humidifiers

Leaks of treated boiler water

Non HVAC System Equipment

Office Equipment

Supplies for Equipment

Laboratory Equipment

ri 4 r








HUMAN ACTIVITIES

Personal Activities

Smoking

Cosmetics (odors)

Housekeeping Activities

Cleaning materials

Cleaning procedures (e.g., dustfrom sweeping, vacuuming)

Stored supplies

Stored refuse

Maintenance Activities

Use of materials with volatilecompounds (e.g., paint, caulk,adhesives)

Stored supplies with volatilecompounds

Use of pesticides

r) el fl


Pollutant and Source InventoryPage 4 of 6



Using the list of potential source categories below, record any indications of contamination or suspected pollutantsthat may require further investigation or treatment. Sources of contamination may be constant or intermittent or maybe linked to single, unrepeated events. For intermittent sources, try to indicate the time of peak activityor contami-nant production, including correlations with weather (e.g., wind direction).



BUILDING COMPONENTS FURNISHINGS

Locations Associated with Dust or Fibers

Dust-catching area(e.g., open shelving)

Deteriorated furnishings

Asbestos-containing materials

Unsanitary Conditions/Water Damage

Microbial growth in or on soiledor water-damaged furnishings








Chemicals Released From Building Components or Furnishings

Volatile compounds

OTHER SOURCES

Accidental Events

Spills (e.g., water, chemicals,beverages)

Water leaks or flooding

Fire damage

22 2








Special Use/Mixed Use Areas

Smoking lounges

Food preparation areas

Underground or attachedparking garages

Laboratories

Print shops, art rooms

Exercise rooms

Beauty salons

Redecorating/Repair/Remodeling

Emissions from new furnishings

Dust, fibers from demolition

Odors, volatile compounds

0, 0 ri.


0 Pollutant and Source Inventory Page of




Sections 2, 4 and 6 discuss pollutant sources. Appendix A provides guidance on common measurements.




Chemical Inventory


Address:

Completed by: Phone:

The inventory should include chemicals stored or used in the building for cleaning, maintenance, operations, and pestcontrol. If you have an MSDS (Material Safety Data Sheet) for the chemical, put a check mark in the right-hand column.If not, ask the chemical supplier to provide the MSDS, if one is available.

Sections 2,4 and 6 discuss pollutant sources. Section 4 discusses MSDSs.

Date Chemical/Brand Name Use Storage Location (s) MSDS on file?


0 Hypothesis Form Page 1 of 2


Address:

Completed by:

Complaint Area (may be revised as the investigation progresses):

Complaints (e.g., summarize patterns of timing, location, number of people affected):

HVAC: Does the ventilation system appear to provide adequate outdoor air, efficiently distributed to meet occupantneeds in the complaint area? If not, what problems do you see?

Is there any apparent pattern connecting the location and timing of complaints with the HVAC system layout, conditionor operating schedule?

Pathways: What pathways and driving forces connect the complaint area to locations of potential sources?

Are the flows opposite to those intended in the design?

Sources: What potential sources have been identified in the complaint area or in locations associated with the complaintarea (connected by pathways)?

Is the pattern of complaints consistent with any of these sources?


Hypothesis Form

Hypothesis: Using the information you have gathered, what is your best explanation for the problem?

Page 2 of 2 4i

Hypothesis testing: How can this hypothesis be tested?

If measurements have been taken, are the measurement results consistent with this hypothesis?

Results of Hypothesis Testing:

Additional Information Needed:

cr74, A,


Index

Air distribution, see also HVAC system, Ventilation 7-8, 24-27, 35, 38, 57-71, 82-84, 88, 92-93, 111-115, 121-135, 146,

177, 193, 201-206Air handling units, see also HVAC system 124-130, 177, 192, 199

Air pressure, see HVAC system, Pressure relationships, and VentilationAirflow, see also Pressure relationships and Ventilation 24, 26, 64, 71, 99, 104, 114, 121-122, 125

Asbestos 63, 147-150, 164-165ASHRAE, see also Standards, guidelines, and advisories 121, 167

Guideline 1-1989 139

Standard 52-1976 126, 138

Standard 55-1981 57, 66, 129, 137Standard 62-1989 8, 14, 28, 34-35, 41, 60, 64-66, 82-87, 115, 126, 136-137

Bioaerosols, see Biological contaminantsBiocides 5, 73, 91, 94-95, 132Biological contaminants 5, 24, 35-36, 40, 48, 56, 63, 76, 82, 86, 91-95, 102-105, 117-118, 125, 127, 129, 131-132, 135,

138, 141-146, 165measuring 105, 117

Boilers, see also HVAC system 87-88, 113, 124, 135Building-related illness (BRI) 11, 86, 101, 105

Carbon dioxide (CO2) 36, 49, 57-58, 60-61, 74-76, 87, 110-115

Carbon monoxide (CO) 10, 37, 56, 58, 75-77, 100, 113, 118, 135

Chemical Inventory 23, 26, 72-73, 169, 221

Chemical smoke 22, 60-61, 68, 75, 77, 110-112Chillers, see also HVAC system 124, 135, 137

Cleaning materials 32, 36, 73, 97

Combustion gases 29, 56, 75, 86, 89, 100, 113Complaint area 49, 53-54, 65, 68-69, 76Complaints 10-11, 27, 32, 46, 103

Indoor Air Quality Complaint Form 15, 32, 169, 181

responding to 14-17Control systems, see also HVAC system 8, 19-21, 23, 26, 31, 34-36, 47, 57, 60, 64-65, 76, 82, 92,

122-126, 128-130, 134-135, 145Cooling coils, see also HVAC system 35, 67, 97, 123-124, 126, 128

Cooling towers, see also HVAC system 24, 28, 35, 89, 101, 135

Dampers, see also HVAC system 24, 60, 65, 87, 125, 130, 133fire dampers 25, 130mixing boxes (mixed air plenums) 124-126

outdoor air dampers 59-60, 125Diffusers, see also HVAC system 58-61, 67, 82-83, 87-88, 113-114, 133

228Index 225

Ductwork, see also HVAC system 36, 61, 73,cleaning 36, 61, 73, 91, 102, 127, 131-132leakage 67, 87, 130plenum 24-25, 61, 67, 87, 92, 123,return 65, 87, 99, 130, 133supply 61, 65, 99-100, 114, 123

125, 130,

Dust 23, 25, 32, 67, 72-73, 118, 126, 131, 138

Elevators 68- 69, 93Environmental stressors 11, 55-56, 77-78, 85

91, 102, 127, 131-132

131, 133

Environmental tobacco smoke (ETS) 6, 9-10, 24-25, 32, 35, 40-41, 66, 73, 81-82, 90, 116, 118, 166EPA, see Standards, guidelines, and advisoriesErgonomic stressors 55-56, 78, 85Exhaust air, see HVAC system and Ventilation 8-9, 58, 65, 82, 89, 114, 124, 133, 154Exhaust fumes 53, 72, 100

Fans, see also HVAC system 22, 48, 87, 89, 124, 130, 133, 145Filters, see also HVAC system 2, 36, 48, 60-61, 84, 91-92, 123, 126-128, 130, 138Fire codes 27, 58, 83Formaldehyde 56, 82, 85, 116-117Furnishings 34, 40, 72-73, 78, 86, 93, 96, 99, 102, 122, 133, 145

Health and safety 52, 56, 63, 76, 101, 105, 117, 147committee 16-17, 40, 76considerations for investigators 52, 56, 63, 76, 101, 105

Humidification, see also HVAC system 35, 56, 60, 90, 101, 129, 141Humidity, see Moisture 24, 49, 56, 67, 60, 82, 89, 94, 110-111, 123, 125, 129HVAC Checklist - Long Form 26, 58, 61, 169, 175, 195-209HVAC Checklist - Short Form 26, 58, 61- 62, 169, 191-194HVAC system 5, 6-9, 57-59, 62, 79, 86, 89, 111, 121, 123, 154

components 57, 64, 83, 87, 94, 123-137design types 7-8, 57-59, 61- 62, 64- 65, 121-123maintenance 22-23, 62, 67, 91, 122operation 6, 25, 52, 55-59, 62, 89, 122, 189zones 47, 58, 76, 82, 112, 121-122, 169

Hypothesisdeveloping and testing hypotheses 46, 57, 67, 71, 74-75, 78-79, 223Hypothesis Form 57, 67, 71, 74, 78-79, 169, 223-224

I AQ Incident Log 16, 49, 169, 183IAQ Management Checklist 42, 169, 171-174IAQ management plan flowchart 32IAQ manager 32-33IAQ profile flowchart 20IAQ task force 13, 17, 40Indoor Air Quality Complaint Form 15, 169, 181Infiltration, see Airflow and Pressure relationshipsIntegrated Pest Management (IPM), see Pest control

2 2 9226 Index

Intermittent problems 10, 55, 59, 72, 74, 77Interview, see Occupant InterviewInvestigation

collecting additional information 20, 25-29, 49-74flowchart 45forming hypotheses, see Hypothesis, developing and testingoutside assistance 20, 40, 45, 47, 63, 105-108, 117reviewing existing records 20-22, 50, 58sampling 74-77, 109-119walkthrough 45, 47-49

Legionnaire's disease 11, 56, 101Lighting 11, 24-25, 55, 77-78, 85- 86Loading docks 23, 25, 37, 89, 100Local exhaust, see also HVAC system and Pressure relationships 9, 22, 40, 65, 82-83, 90, 92, 94, 97, 99-100, 102, 137Log of Activities and System Operations 52, 53, 58, 77, 139, 169, 189

'Maintenance 24, 31, 34, 36, 67, 97preventive 23, 36records 22-23schedule 23, 34-35, 139

Manometer 36, 58, 68-69, 110Material Safety Data Sheets (MSDS) 20, 28, 32, 35, 38-40, 73Measurement

comparing to standards and guidelines 75- 76, 87devices 48, 58, 75, 109-119developing measurement strategy 48, 74-77

Microbiological contaminants, see Biological contaminantsMildew, see Biological contaminantsMitigation

evaluating approaches 102-103judging success 75, 103-104managing projects 103

persistent problems 104

using air cleaning 81, 84-85, 89, 92using exposure control 81, 85, 93, 96-99using source control 81-82, 89-101using ventilation 41, 81-84, 87-100

Mixing boxes, see also HVAC system 61, 124-126Moisture 23-24, 95, 128, 131, 141-146

humidity 24, 60, 120, 122, 137-138, 141-146water damage 24, 73, 94, 128, 131-132, 141-142

Mold, see Biological contaminantsMultiple chemical sensitivity (MCS) 12

NIOSH, see also Standards, guidelines, and advisories 41, 63, 75, 81, 84, 111, 116, 119, 147149, 154, 157,164-165, 167

Noise 11, 55, 77-78, 85-86, 127

Index 227

230

Occupants 5, 10-11complaints 10, 46, 48, 50, 72, 131density 24, 66, 73, 78, 87, 122, 136Occupant Diary 52, 77, 169, 187Occupant Interview 50-52, 169, 185occupant relations (IAQ management plan) 40

Odors 8, 24-25, 49, 65Outdoor air intake 5, 10, 25, 56, 58, 65, 89, 99-100, 121, 124-125Outdoor sources of contaminants 5, 25, 56- 57, 72-74, 86, 89, 102, 113, 127

Peppermint oil 69Pest control 23, 32, 37-38, 43, 73, 84, 89

Integrated Pest Management (IPM) 38

pesticides 23, 32, 37-38, 76, 85, 96, 116Pollutant pathways and driving forces 5, 9-10, 50, 54, 69-70, 79, 82, 84, 89, 97, 100, 115, 152Pollutant and Source Inventory 25-26, 28, 72-74, 169, 213Pollutant Pathway Form for Investigations 67, 69, 169, 211Pollutant Pathway Record IAQ Profile 26-27, 33, 169, 175Pressure relationships, see also Airflow and HVAC system 8-9, 27, 35, 37, 45, 66-68, 71, 82-83, 89, 93, 98, 100-111, 127,

133-134, 144negative/positive 8, 26-27, 37, 70, 82-83, 89, 98, 100, 110-111, 127, 132, 141, 154-155

Preventive Maintenance, see also Maintenance 36, 132Psychrometer 111, 143Psychosocial stressors 11, 55- 56, 77-78Purchasing 32, 35, 37, 41, 81

Radon 5, 89, 151-152, 167Recirculation, see VentilationRedecorating/Renovation/Remodeling 21, 32, 34, 40, 55, 66, 73, 86, 99Return air, see HVAC system and VentilationRoofing 23, 85, 89, 99

Sampling and analysis, see MeasurementSick building syndrome (SBS) 11, 155Smoking, see Environmental tobacco smokeSources, see also Pollutant and Source Inventory and specific sources (by name) 5, 6, 8-9, 26, 28, 35, 48, 72-74, 76,

81-82, 90Special use areas 25, 65, 73, 86, 90, 93, 96, 98, 133-134Standards, guidelines, and advisories, see also ASHRAE, NIOSH 43, 75-76, 167Storage practices 23, 25, 37, 73, 97Supply air, see HVAC system and VentilationSurface contamination, see also Biological contaminants 6, 37, 76, 86, 91, 94

Terininal devices, see HVAC systemTesting and balancing 21, 43, 48, 58, 87, 92, 94, 98-99, 103, 123Thermal comfort 7, 24, 56-57, 87, 89, 110-111, 121, 133-134, 137, 167Thermal mass balance 114-115Thermostats, see also HVAC system 24, 59-60, 64-65, 67, 111, 122, 134-135, 145

228 Index 231

Toolsfor IAQ investigations 45, 48-50, 58, 68, 72, 77, 109-119for IAQ profiles 20, 22

Total volatile organic compounds (TVOCs) 115-116

Tracer gas 58, 69, 77, 112-113, 126

Trainingm 31, 33, 41, 117, 139, 167

Trash disposal 23, 37, 89

Unit ventilators, see HVAC systemUnsanitary conditions 24-25, 38, 65, 67, 72, 94, 117

Ventilation, see also Airflow, ASHRAE 62-1989, HVAC system, Pressure relationships 7, 8-10, 24, 65, 83-84, 110, 113,122, 126, 130-131, 133, 136, 139, 144, 167air distribution 61, 69, 86-87, 95, 104outdoor air 24, 65, 82-83, 86-87, 91-92, 96, 99-100, 102, 113-115, 121, 122-125, 135, 145measuring 87-88recirculation 82, 92total air 65, 82-83, 95, 99, 104, 113-114underventilation 24, 56-57, 60, 66-67, 82-83, 87-88, 112-113

Ventilation Worksheet 169, 179Vibration 11, 77-78, 85-86Volatile organic compounds (VOCs) 6, 82, 96, 99, 102, 115-116

VValkthroughprofile 20-25investigation 45, 47-49

Water chillers, see also HVAC system 137

Water, see Moisture

Zone/Room Record 28-29, 61- 62, 169, 177

Index 229

_3?

*U. S. GOVERNMENT PRINTING OFFICE: 1992/650-459/

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