DMG 22. Building Energy Management Systemsdocshare01.docshare.tips/files/28817/288178063.pdf · Building energy management systems ... and contractors in execution of contracts for

Building energymanagement systems

SPECIALIST SERVICES, FUELS AND MECHANICALDEFENCE ESTATESMINISTRY OF DEFENCELONDON: The Stationery OfficeJanuary 2001

Design & Maintenance Guide 22

DMG 22Building Energy Management

© Crown Copyright 2001

Published with the permission of the Ministry of Defenceon behalf of the Controller of Her Majesty's Stationery Office

Applications for reproduction should be made toThe Copyright Unit,Her Majesty's Stationery Office,St. Clements House,2-16 Colegate,Norwich NR3 1BQ

ISBN 0 11 772934 5

First Published 2001

Printed in the United Kingdom for the Stationary OfficeTJ 3543 C1O 05/01

January 2001

DMG 22Building Energy ManagementSystems

Foreword

This Guide has been produced by Defence Estates (DE), Central Business Unit,Specialist Services, under the patronage of the Defence Utilities Working Group.

The purpose of this Guide is to provide assistance to Project Sponsors, PropertyManagers, specifiers, designers, energy managers and operators in theprocurement, use and maintenance of Building Energy Management Systems(BEMS). Due to the wide potential readership, a chart has been preparedoverleaf showing topics likely to be of specific interest to particular readershipgroups.

Whilst this Guide was commissioned by the DE for use on Ministry of Defence(MOD) contracts, it is acknowledged that it could be usefully applied to othercontracts. DE commends the use of this document by other GovernmentDepartments. It may also be used by non-government organisations. However, nowarranty is given as to the accuracy of the content of this Guide, or its fitness forany purpose.

When this Guide is used in connection with a Defence contract then it shall beread in conjunction with further documents setting out particular contractualrequirements.

This Guide has been compiled for the use of the Crown, its technical advisorsand contractors in execution of contracts for the Crown. The Crown herebyexcludes all liability (other than liability for death or personal injury)whatsoever and howsoever arising (including, but without limitation, negligenceon the part of the Crown, its servants or agents) for any loss or damage howevercaused where the Guide is used for any other purpose.

January 2001 iii

DMG 22Building Energy Management ForewordSystems

The following table provides guidance to the reader on which sections of theGuide are most likely to be of particular relevance to each type of reader:

Executive Summary

1 Introduction

2 Feasibility, design,procurement

3 Installation, commissioningperformance testing

4 BEMS operation

5 BEMS maintenance

6 Energy monitoringand targeting

Analysis of requirements

Tender summary

Energy consumptionbenchmarks

Glossary of Terms

Bibliography

Very significantGeneral interestBackground information

January 2001


Acknowledgements

This Guide has been compiled by consulting engineers Ove Arup & Partners.

The authors would like to record their gratitude to the staff at the followingseven sites within the MOD Estate for their time and co-operation inresearching the study:

R N Ensleigh, BathRNAS YeoviltonRAF BramptonRAC Centre Bovington, WarehamRSS BlandfordRAF ConingsbyDefence Procurement Executive, Abbey Wood, Bristol

Gratitude is also extended to the Building Services Research and InformationAssociation (BSRIA) whose published guidance has been used in the productionof this document.

CONTACT FOR QUERIES

Specialist ServicesDefence EstatesBlakemore DriveSutton ColdfieldWest Midlands B75 7RLTel No: 0121 311 2294

January 2001

January 2001


Abbreviations

Building Energy Management System

Building Management System

Building Services Research and Information Association

Chartered Institution of Building Services Engineers

Central Processing Unit

Direct Digital Control

Defence Estates (Formerly Defence Estates Organisation)

Defence Estates Organisation

Establishment Works Consultant

Heating, Ventilation and Air Conditioning

Heating and Ventilating Contractors Association

Information Technology

Monitoring and Targeting

Original Equipment Manufacturer

Personal Computer

Private Finance Initiative

Planned Preventive Maintenance

Public Private Partnership

Structured Cabling System

Variable Air Volume

January 2001 vii

BEMS

BMS

BSRIA

CIBSE

CPU

DDC

DE

DEO

EWC

HVAC

HVCA

IT

M&T

OEM

PC

PFI

PPM

PPP

scsVAV

viii 2001


Contents

Section 11.11.2

1.31.4

1.5

1.6

Section 22.1

2.2

2.3

2.4

2.5

2.6

2.6.1

2.6.2

2.6.3

2.7

2.8

2.9

2.10

2.11

Section 33.13.2

3.3

FOREWORDACKNOWLEDGEMENTSABBREVIATIONS

CONTENTSEXECUTIVE SUMMARY

INTRODUCTION

AIMS AND OBJECTIVES

TERMINOLOGY

WHAT IS A BEMS?

HISTORY

ADVANTAGES AND DISADVANTAGES

OPTIONS AND FUTURE DEVELOPMENTS

FEASIBILITY, DESIGN AND PROCUREMENTGENERAL

FINANCIAL APPRAISAL

INDICATIVE COSTS

JUSTIFICATION

FEASIBILITY

DESIGN AND SPECIFICATION

DesignSpecificationTypes of SpecificationPROCUREMENT

COMMUNICATIONS

SOFTWARE

STANDARDS AND REGULATIONS

COPYRIGHT

INSTALLATION, COMMISSIONING, PERFORMANCE TESTINGINSTALLATION

COMMISSIONINGDRAWINGS AND DOCUMENTATION

iiiV

viiixxi

1112

4

6

7

9

9

9

10

10

13

13

13

14

14

15

16

17

17

18

1919

2022

January 2001


Contents

Section 44.1

4.1.1

4.1.2

4.2

4.3

4.4

4.5

Section 55.1

5.2

5.3

5.3.1

5.4

5.5

Section 66.1

6.2

6.3

BEMS OPERATIONOPTIONS FOR MANAGING BEMS

Examples of the functions of staff who operate and manage BEMSOther OptionsOUTLINE SPECIFICATION FOR LEVELS OF BEMS OPERATOR

TRAINING

COSTS OF OPERATING BEMS

UPGRADING AND REFUBISHMENT OF BEMS

BEMS MAINTENANCE

PREAMBLE

MAINTENANCE COSTS

CONTRACT ARRANGEMENTS

Operating and Maintenance DocumentationSPARES AND CONSUMABLES

RECOMMISSIONING

ENERGY MONITORING AND TARGETINGREVIEW AND RELATIONSHIP WITH BEMS

ADVANTAGES AND POTENTIAL COST SAVINGS

COST IMPLICATIONS

ANNEX A - TYPICAL COSTS AND SAVINGS ASSOCIATED WITH BEMSANNEX B - ANALYSIS OF REQUIREMENTSANNEX C - TENDER SUMMARY

ANNEX D - ENERGY CONSUMPTION BENCHMARKING

FOR MOD BUILDINGSGLOSSARY OF TERMS ASSOCIATED WITH BEMSBIBLIOGRAPHY

2323

24

25

25

27

27

27

2929

29

29

30

30

31

3333

34

35

3739

43

4547

49

January 2001


Executive Summary

A Building Energy Management System (BEMS) is a computer based centralisedsystem that helps to manage, control and monitor particular engineeringservices within a building or group of buildings. Use of a BEMS can limit energycosts and labour requirements by improving plant efficiency and effectiveness. Itcan also provide a more comfortable environment for the building occupants andact as a focal point for alarms.

BEMS have evolved from being a simple supervisory control tool to a totallyintegrated computerised control and monitoring system.

Some advantages that a BEMS can provide are:

simple operation with routine and repetitive functions programmed forautomatic response

flexible time scheduling of plant and heating to meet site changes such asholidays, training exercises and operational requirements

remote switching of plant and adjustment of set points

faster and better response to occupant needs

reduced energy costs through centralised control, monitoring and energymanagement programmes

ability to cycle/control site electrical demands

better management through automatic alarm reporting, historical recordsand maintenance programmes

graphical representation of plant operating conditions

improved operation through integration of sub-systems (eg. lighting andaccess)

improved plant performance and life expectancy

real time collection and recording of data for improved analysis ofequipment or energy uses.

To obtain a successful BEMS installation:

provision needs to be made for ongoing operation and maintenance

operators must be skilled and fully trained on the use and operation ofBEMS

existing plant (when being overlaid with a new BEMS) must be capable ofperforming its required functions

the system needs to be correctly specified, installed, commissioned andoperated.

January 2001

DMG 22Building Energy Management Executive SummarySystems

the functions of a BEMS

how to justify a BEMS

information required for a feasibility assessment

design and specification aspects

guidance on procurement

pointers for satisfactory installation and commissioning

the importance of record documentation

the need for ongoing operation and maintenance

the key role played by trained personnel.

xii January 2001

This Guide sets out:


1 Introduction

1.2 TERMINOLOGY

BEMS is a generic term used to describe computer-based control systems forengineering and building services such as air conditioning, lighting, access,security, monitoring etc. Other titles used for such equipment are BuildingManagement System (BMS) and Energy Management System (EMS). The termBEMS has been identified as the normal acronym for such systems and adoptedthroughout this Guide. Other terms are synonymous with this.

January 2001

provide a history of BEMS

list their advantages and disadvantages

address how to justify the application of BEMS

assess feasibility at a specific location

identify requirements for installation, testing and commissioning

explain the importance of operation and maintenance

demonstrate their potential for energy monitoring and targeting.

It provides background information, particularly for those who have littledetailed knowledge of such systems.

Further guidance is given in Specification 47 - Building Energy ManagementSystems, due to be published in 2001.

This Guide is intended to:

selection

design

installation

testing

commissioning

use

maintenance.

1.1 AIMS AND OBJECTIVES

The principal purpose of this Guide is to provide a single source of informationregarding BEMS for those involved with:

DMG22Building Energy ManagementSystems

Section 1 Introduction

1.3 WHAT IS A BEMS?

A BEMS is a computer-based system that helps to manage, control and monitorbuilding engineering services within a single building or a group of buildings.Such a system, when properly designed, installed, commissioned and operatedwill significantly improve the operational efficiency of the engineeringinstallation and its cost effectiveness in terms of labour and energy costs. It canalso help to provide a more comfortable environment for the building occupants.

A BEMS typically has at least one principal operator position (or centralstation), connected via a communication network to remote outstations (orcontrollers), which can function independently and provide local control to theplant to which they are connected. They can also collect and respond to datafrom the central station or other outstations. The central station is a userinterface at which various functions can be available depending on the client'srequirements. It may be located remotely eg. at a headquarters building or worksdepartment.

Figure 1 demonstrates the components of a BEMS.

Figure 1Components of a BEMS

BEMS Central Station(Personal Computer)

Other OperatorInterface

Remote OperatorInterface

SITE DATA NETWORK

Controllers Hanger Group HQAccommodationBlock

Unitary controllersserving dedicated plant

Roomchillerunit

VAVterminal- box

AHU Standbygenerator

Heating pipework

January 2001



Figure 2 illustrates how the BEMS controller functions.

Figure 2Example of BEMS inoperation

Temperaturesensor

Humiditysensor

Velocitysensor

Sensorinputs

Time schedules(contained withinthe controller)

Elements of building engineering services with potential for control ormonitoring by a BEMS are:

• heating

• ventilation

• air conditioning

• domestic hot and cold water

• lighting

• electrical supply/distribution

• electrical standby services

• energy consumption (ie. reading electricity, gas, water meters)

January 2001 3

DWG 22Building Energy Management Section 1 IntroductionSystems

There is no reason, however, why any system needing to be monitored remotelycould not be integrated into a BEMS to provide a central focus point.

Most current generation BEMS provide the management interface at the centralstation through a personal computer (PC). The operating system for the centralstation is likely to be Microsoft Windows, since this has become an industryleader. The component structure below the central station comprises acommunication network, local controllers and field devices (eg. sensors, actuatorsand meters). Different suppliers use different communication protocols totransfer data, and within different generations of equipment from a singlesupplier there may be variations in communication standards. Where differentsuppliers equipment exist, or different generations of the same supplier, it maybe possible to integrate the control components, but due to differentcommunication standards and operating criteria this may not be astraightforward process. As this integration can be expensive, costs should becompared to replacement with directly compatible equipment.

CIBSE note in their Energy Efficiency in Buildings Guide (published in 1998),that energy savings of between 10% and 20% can be achieved through the use ofa BEMS, compared with independent controllers for each system, thoughopportunities for savings of this size will not always be available.

1.4 HISTORY

The development and processing power of computers, and in particularmicroprocessors, has enabled a steady growth since the late 1960s from separate,independent and dedicated control equipment to increasing degrees ofautomation, control and communication. One driving force was to reduce theamount of cabling by the use of data networks.

Early systems were structured around a central computer called the 'head end'or 'front end' which contained the processing capability, linked by fixed wiring toeach sensor or actuator device (eg. a room thermostat or a motorised valve).Although the processing capability was limited, only providing start/stop controland system monitoring, a central facility became available where all control andperformance information could be accessed such as alarms, room temperaturesand on-off switching times. This reduced the need for frequent site visits andhence offered more efficient use of maintenance operatives.

Because the central processor carried out all the functions, the system capabilitywas limited by the available capacity. Such systems were generally veryinflexible and not user friendly.

January 2001

electrical maximum demand

security/access equipment

fire detection/alarm systems

vertical transportation

specialist equipment (eg. standby facilities, smoke control and fumecupboards etc.)

catering services (eg. ventilation, electricity and water usage)



The next development was the introduction of direct digital control (DDC) andthe reduction of the dependence on the central computer by distributing thecomputing power round the building or estate within local microprocessors, eachwith a limited input/output capacity. This style of system became known as'distributed intelligence'. System design and operational requirementsdetermined the need for a central computer. This was not essential because thesystem 'intelligence' was provided by the outstations. Provision of acommunication network to link the outstations and allow data to be passedbetween them promoted the stand-alone outstations to a BEMS.

Use of BEMS for control and monitoring of building services significantlyincreased over the decade from 1980. Interest increased also in the potential tolink Heating, Ventilation and Air Conditioning (HVAC) equipment controls usingBEMS for at least alarm monitoring from other stand alone systems such aslighting, lifts, fire and security and providing a single point for alarms to beregistered.

As computer processing power increased and costs reduced, the capabilities andapplications of BEMS grew, though on occasions the installations becamedifficult to manage. Installation standards were not always followed,commissioning became difficult and not always effective, which resulted insystems that failed to achieve their original expectations.

Building owners and operators became disenchanted with "automated systems"which failed to deliver the promised solution. However, they accepted that if thesystems could be simplified, designed properly, installed correctly and fullycommissioned, they would be a useful tool for running properties.

As microprocessor technology developed, stand-alone controllers becameoperated alone or linked through a communication network to other controllersand a central point of information access. Such units, where they serve terminalunits such as fan coil units or Variable Air Volume (VAV) boxes have becomeknown as unitary controllers. Plant manufacturers or Original EquipmentManufacturers (OEMs), purchase unitary controllers and fit them to their ownproducts. These can provide an opportunity for later integration into a BEMSthrough a communication network. Computer power has now become fullydistributed, with the central computer becoming the 'host' for loadingprogrammes, interrogating performance and recovering data. Systems have alsobecome more user friendly and easier to programme.

Figure 3Summary of changes inBEMS technology

BEMS with outstations

1970 1980 1990 2000

January 2001

DMG 22Building Energy Management Section 1 IntroductionSystems

1.5 ADVANTAGES AND DISADVANTAGES

The use of a BEMS provides an integrated computer based facility for thecontrol and monitoring of the building engineering services.

Advantages are:

routine and repetitive functions are programmed and responded toautomatically (eg. daily on and off times, holiday scheduling, operationalprogramming for different buildings, periodic testing of standby plant)

relatively simple operation for trained users (eg. access to detailedinformation such as room temperatures to monitor plant performance;modifying operating times to match changes to building use)

quick response to occupant complaints about environmental conditions(the sensitivity of BEMS can highlight potential problems and allowadjustments to be made before occupants initiate complaints)

reduced energy consumption and hence costs by central monitoring andcontrol (savings may be up to 10% by constant fine tuning to matchoccupational needs)

ability to cycle or control site electrical demand

improved management information such as historical records, alarm logsand hours run can demonstrate that environmental criteria have beenachieved; alarms have been actioned and plant maintenance can be moreprecisely managed

graphical representation of plant operating conditions and internalenvironment, providing quick and simple understanding of theinformation presented

integration of system control and operation through software links(allowing increased opportunities for fine-tuning of controls to theparticular application)

improved plant performance and life expectancy (eg. by establishing keyoperating criteria and monitoring performance efficiency).

Disadvantages that can apply include:

any BEMS installation will have costs associated with it. These will notonly be the initial design and installation, but also the subsequentoperation and maintenance (see para 2.1)

possible disruption to normal plant operation during BEMS installation

need for a skilled operator to ensure maximum use is made of the system

the effective potential of a BEMS can be very sensitive to properspecification, full consideration of condition and ability of plant to becontrolled, commissioning by a skilled BEMS specialist and continuedmaintenance

difficulty in integrating with existing equipment especially regardingcommunication protocol or the need for new controls or sensors to allowintegration

January 2001


requires commitment at all levels throughout its operational life tomaintain maximum effectiveness

unless carefully chosen, certain aspects of BEMS can become obsoleterelatively quickly

unless correctly specified, installed, maintained and operated BEMS canincrease costs and environmental impacts.

1.6 OPTIONS AND FUTURE DEVELOPMENTS

The processing power of electronic equipment being used within a BEMS meansthat any system needing to be controlled or remotely monitored could beaccommodated, providing the cost of the initial installation and ongoingoperation and maintenance can be justified.

Greater integration between different systems such as lighting, fire alarms,security and BEMS is likely to develop as the full capabilities becomerecognised. The links at present tend to be for monitoring and alarm reporting.As users investigate different options and the potential of the full equipment,greater confidence will be developed.

Whilst communication standards do exist, different suppliers and manufacturersstill have their own for their respective systems. As clients begin to demandsystem integration to allow data from different components and systems to beviewed and managed centrally, and control functions to be enhanced by sharingdata, greater flexibility will be achieved. The components of BEMS from differentsuppliers are expected to become more compatible.

Unitary controllers are likely to become standard items of plant and equipment.This may also influence the move towards communication standards, as greaterintegration between suppliers equipment will be required. Unitary controllerscan provide programmable memories for field devices such as temperaturesensors or valve actuators, allowing them to be programmed and commissionedbefore delivery to site. On-site commissioning will, however, always be required.

The costs of outstations and central stations will be influenced by the continuousdevelopments of IT equipment, with the expectation that greater processingcapability will be obtained for less cost. The cost element of a BEMS taken upwith the installation of the communication network may be reduced where an ITnetwork is available. Alternatively, the use of radio communications for bothinternal and external links has considerable potential to grow and develop,particularly between field devices and their associated outstations. Overall costsof BEMS are unlikely to reduce. Whilst some components such as electronicequipment may become cheaper, other hardware costs and the system design andengineering will continue to be the major proportion of the price and not provideopportunities for savings.

As the volume of data increases, the levels of management information will rise.Exception reporting, to show potential problem areas with likely causes andpossible solutions, may be developed to enable full use to be made of theavailable information.

January 2001


January 2001


2 Feasibility, design andprocurement

GENERAL

This section helps to identify the factors for choosing a BEMS and providesguidance in establishing the feasibility and requirements for a BEMS. The mostcommon reasons for considering the use of BEMS are:

for new builds where costs are comparable to other forms of control

to replace existing old or failing controls where the difference in costs areoutweighed by the benefits provided by the BEMS

to improve the system where the benefits outweigh the costs

where there is a need for stringent control and monitoring levels ofbuilding services.

2.2 FINANCIAL APPRAISAL

A key factor in building a business case for a BEMS will be a financial appraisalover the proposed life of the system. Annex A is a simple table to help provideinitial indications of the likely costs and savings associated with BEMS. MODGuidance and Policy for carrying out full financial appraisals is given in:

JSP 414 Part 4 Chapter 16 Investment Appraisal and Post ProjectEvaluation

DEO (Works) 1996 DEO Technical Bulletin 96/04 - Through Life Costing

DEO (Works) 1996 DEO Technical Bulletin 96/03 - Value Engineering

MOD Guide to Investment Appraisal and Evaluation.

Further guidance is also given in:

Appraisal and Evaluation in Central Government (Treasury Guidance1997)

Appropriate local guidelines should also be followed.

January 2001

DMG 22Building Energy Management Section 2 Feasibility, design and procurementSystems

2.3 INDICATIVE COSTS

As general background information, three generic types of installation areconsidered with outline cost information based on Quarter One year 2000. Theseare not intended to be used for budget purposes, only to provide outline guidanceof the order of costs for the different types of properties. The particularrequirements for a specific location may result in significant variations fromthese figures.

Total installedcost of BEMS(new greenfieldsite)*

Property Type OneVery large major site with numerous buildings and facilities £300,000eg. Naval Dockyard; RAF Operational SiteTotal utilities cost per annum (electricity, oil, gas, water)£1 million.

Property Type TwoMedium to large £75,000eg. Large single building or complex of buildingsTotal utilities cost per annum£200,000.

Property Type ThreeSmall to medium single building or small complex of £30,000buildingsTotal utilities cost per annum(electricity, oil, gas, water)£50,000* Installation in existing buildings will require an increase of10% to allow for additional design and installation costs.

2.4 JUSTIFICATION

All building services need controls. BEMS can be cheaper than individualcontrols, particularly for new buildings where they can be justified on first costsfor almost all types of buildings. For refurbishment or replacement situations,first costs alone may not indicate that a BEMS is appropriate. Whole life costsshould also be investigated when system flexibility, monitoring and centralcontrol capability can be taken into account. Upgrading costs will need to becompared with potential energy savings.

CIBSE indicate energy cost savings between 10% and 20% by use of BEMS intheir 1998 Energy Efficiency in Buildings Guide. As a rule of thumb, a retrofitBEMS can yield a 10% direct fuel cost saving against a reasonably wellmaintained conventional control system when properly designed, installed andcommissioned.

The benefits of using a BEMS are the flexibility of the controls available,communications capability (particularly for operational data between plant andsystem) and overall performance monitoring.

10 January 2001


A BEMS can provide three key advantages over stand alone control:

provision of management information

remote operation, interrogation and alarm monitoring

greater flexibility and range of control strategies.

BEMS will not compensate for fundamentally inefficient buildings and plant.

Benefits of a BEMS can include:

improved environmental (eg. temperature) and time control from centrallocation

rapid communication (system monitoring, operation and control) withremote sites, without physical visits

improved comfort for building occupants

automatic fault reporting at central location (with predetermined levels ofaction)

monitoring and targeting of energy consumption

allows easy trial and monitoring of building response characteristics andrelated energy saving proposals such as lunch time set back of heating.

graphical representation of plant performance and environmentalconditions.

Examples of specific capabilities of BEMS are:

scheduling plant start / stop times

fuel consumption recording / energy metering

plant sequencing / optimisation

filter condition monitoring

electrical maximum demand limiting

lift monitoring

lighting control

hours run recording and trend logging

security management

alarm handling

'at a glance' information presentation.

Whilst these are also available using stand-alone controls, integration into aBEMS provides the opportunity for achieving the greatest savings and operatingefficiency.

January 2001 11


In addition to the technical capabilities listed above, BEMS can provide theopportunity for improved financial control, for example, by billing sub-tenantswhere suitable metering is provided. Close monitoring of occupancy times andadjusting BEMS settings can produce energy savings. Reduced maintenanceattendance by scheduling work on an hours run basis can lead to manpowersavings.

Before purchasing such a system, it is important to consider what the controlsare intended to do and how they will achieve this.

To provide a framework for this, Annex B - Analysis of Requirements provides aseries of questions to help analyse requirements at a specific location, includinga pro forma to identify which plant and services are to be covered by the BEMS.The particular plant or system will generally determine the type of controlrequired. Each control requirement should be considered separately and thedetails listed. It is important to avoid an over specified or unnecessarily complexcontrol system for the particular application. Advice on what is necessary andappropriate, and help on completion of the check list can be obtained from theEstablishment Works Consultant (EWC) through the Property Manager orthrough the Establishment Energy Focal Point.

The larger the number of systems or plant items listed for the project, and thelarger the number of control or monitoring requirements, then the greater is thelikelihood for a BEMS to be the appropriate choice for controlling the buildingservices.

For an existing installation, a list of questions to consider is given below:

• is there an operational requirement for central monitoring or control?

• do the existing controls meet current good practice? (eg. time control,weather compensation, optimum start/stop)

• can the existing control be adequately operated and maintained?

• does energy use compare well with published guidelines? (see Annex D -Energy consumption benchmarks for existing MOD buildings)

• is there a need to attribute responsibility for utilities to specific users?(eg. billing of non-entitled users and resource accounting)

• are consumption records needed for tariff/consumption profile analysis?

• is there an opportunity to integrate control of different engineeringservices?

• has the building function changed?

• have good housekeeping measures to reduce energy consumption beencarried out.

• are the building occupants satisfied with their environment?

These questions are included in Annex B - Analysis of Requirements

Once a decision in principle has been taken to consider a BEMS, the fullpotential benefits and costs of achieving them need to be examined.

12 January 2001


2.5 FEASIBILITY

BEMS are becoming the norm in many larger new buildings, as their first cost issimilar to stand alone controllers.

In existing buildings, assessing the feasibility of a BEMS can be more difficult.Where existing stand alone control equipment is available, the suitability,practicality and cost of retaining and incorporating components of it into a largerBEMS needs to be assessed.

The following considerations are aimed at existing buildings, but could also beapplied to new buildings.

• Zoning of Building Services

Are these adequate for energy efficient operation and match currentand proposed occupant requirements?

• Primary Plant

Does this have stand alone control, could it be linked with a BEMS?

• Existing stand alone controls

Are they still supported by manufacturers? Can they beeconomically integrated into a new BEMS? Control equipmentinstalled in the late 80s, early 90s or earlier may have limitedfunctions available and be difficult to reprogramme.

• Existing BEMS

Is there an existing BEMS available that could be used?

2.6 DESIGN AND SPECIFICATION

2.6.1 Design

A BEMS is a powerful tool that allows building owners, operators, and managersto understand the function and control the operation of engineering plant andservices for which they have responsibility. It is important to note that howevera BEMS is designed or specified it can only control within the limits andaccuracy of the equipment to which it is connected.

There are a wide variety of systems available that can provide control or simplymonitor the status of plant. A purchaser needs to be clear and unambiguousabout the plant and equipment to be served by the BEMS and the degree ofcontrol required.

The extent and method of design will depend on the size and complexity of theinstallation and its controls, the technical competence of the client and anyrelationship which exists with a preferred supplier.

Where the BEMS is being overlaid on existing plant and equipment, controldevices such as sensors and actuators may not be compatible or suitable forconnection to the BEMS. Allowance for this will need to be included in the costsof the work.

January 2001 13


Section 2 Feasibility, design and procurement

Control of different engineering systems such as HVAC, lighting, major plantitems such as chillers, and life safety (eg. fire) has traditionally been keptindependent. BEMS can provide opportunities for a degree of integration, butthis is likely to be limited to alarm monitoring or sequence initiation. The extentof integration will be governed by the risks involved. Plant that is safety critical,has military operational implications or operates under its own dedicated controlsystem may not be appropriate for integration.

2.6.2 Specification

The objectives of a specification are to:

14 January 2001

provide a firm basis tor a tenderidentify required performance criteriaminimise misunderstandingdefine responsibilitiesprovide like for like comparisons between different proposals.

The specification provides basic information together with exact functionalrequirements, where appropriate, for the specific application. Further detailedguidance regarding this is provided in Specification 47 - Building EnergyManagement Systems to be published in 2001.

The initial step when preparing a specification is to define the buildingmanagement strategy from which a specification can be developed. To achievemaximum benefit the strategy must take account of the function of each buildingand the existing or proposed operation and maintenance manpower availability.For large, complex applications it may be appropriate to appoint a professionaladvisor for this role. Advice on this can be obtained from the EWC through theProperty Manager, or through the Establishment Energy Focal Point.

2.6.3 Types of Specification

Two generic types of specification can be identified:

Performance

Functional

states how the system will operate in strategic terms, with anoutline description of what is to be controlled and monitored.

gives detailed requirements for the system, including controland monitoring strategies and the devices included, such ascontrollers, sensors and actuators.

Both types of specification should describe the features to be provided, standardsto be met including materials and workmanship, testing and commissioningrequirements, training to be carried out and guarantees to be provided.

The type of specification will be dictated by the particular application andintended procurement strategy. Where a specialist controls contractor is to beused and competence has been demonstrated and proved on similar work, aperformance specification may suffice. The same type of specification may also beappropriate for buildings with relatively simple engineering services and no needfor elaborate control. However, where a building has complex plant such as fullair conditioning, or where environmental conditions have to be closely controlledwithin strict limits and there are considerable inter-relationships between thecontrol sequences, a functional specification will be required to ensure theclient's requirements are fully defined and able to be interpreted by the supplier


and installer. Care must be taken to ensure BEMS equipment is compatible withall systems and its operation does not allow plant to operate outsidemanufactures parameters, normal duty ranges or operational limits.

In 1998 The Building Services Research and Information Association (BSRIA)published a Library of Control Strategies (Application Guide AG7/98) as areference document for when the controls are being developed, specified andconfigured. The strategies can be used when specifying control systems as anindependent source of control solutions. The provision of this Library does notremove the onus from designers to ensure that an appropriate working solutionis produced.

To create a specification for a particular installation from the strategies withinAG7/98 the designer needs to:

• decide which 'plant functions' are required to make up the whole system

• decide for each plant function which of the available plant modulesoptions is to be used

• for strategies which offer alternatives or options, decide which arerequired in the specific application.

2.7 PROCUREMENT

A number of options are available. These include:

January 2001 15

direct purchase from a specialist supplier of controls equipment

direct purchase from a systems integrator (who obtains components suchas controls equipment from a specialist supplier and designs, installs andcommissions the system to meet the user's requirements)

use of a controls specialist to design the system, tender the work andoversee installation and commissioning

produce in-house, an outline brief of requirements and tender the workfor purchase

produce in-house, an outline brief of requirements and tender for leasingan installed BEMS (where such a leasing agreement is deemedappropriate). The lease agreement may include upgrades to the BEMSover the stated period of the lease agreement.

incorporate the BEMS installation within a Private Finance Initiative(PFI)/Public Private Partnership (PPP) arrangement.

lease the BEMS through the Facilities Management Contractor.


2.8 COMMUNICATIONS

Two aspects of communications need to be considered:

1. The information being communicated.

Computers need precise, rigidly defined rules and protocols for successfulcommunication.

Typically, translation problems occur when trying to connect productsmade by different manufacturers, or in some cases, different versions ofproducts made by the same manufacturer.

Traditionally, different systems such as lighting, HVAC and life safety (eg.fire) have had separate, dedicated controls. Relevant specialists shouldbe fully consulted where safety critical systems are to be connected to aBEMS.

Communication standards allow transfer and interpretation of databetween different parts of the BEMS and integration of equipment fromdifferent suppliers. There is no single agreed communications standard,at present, followed by all BEMS suppliers. Several exist and are beingused by different suppliers.

2. Physical communication system between all parts of the BEMS (eg. datacabling).

The elements of a BEMS need to be linked together to transfer datathrough a communication network. The most common method is datacabling using shielded or unshielded twisted pair. Other options includefibre optics, which can provide increased security, radio links, which maybe more appropriate when long distances (eg. across an operational RAFsite) are involved, mains borne signalling, where the electricaldistribution system is suitable and modem links to public or privatetelephone networks.

Existing communication network cabling may be available, eg. redundantvoice systems, but will need to be checked and proved suitable beforeinclusion into the project scheme. Dedicated voice networks usingmodems, can provide a basic communication infrastructure, particularlyon extensive sites where buildings are spread over a large area. Thisapplication can result in prolonged times for data transfer and problemswith data accuracy which may have implications if used for generatingenergy bills.

Alternatively, an existing IT cabling system may be available. Officeaccommodation in particular is increasingly likely to have a structuredcabling system providing an infrastructure on each floor, with a grid ofoutlet connections allowing connection of IT equipment such as PC's andprinters. BEMS may be able to use this to link major components directlytogether (eg. controllers and the central station). The cost of integrating aBEMS with an IT structured cabling systems (SCS) will depend on howmuch of the SCS is required.

Where it is proposed to use an existing or proposed general use cablingsystem for a BEMS, application for this must be made in sufficient timeto ensure its availability when required. The continuing availability ofshared access to the system also needs to be confirmed.

16 January 2001


If the SCS is installed at the same time as the BEMS (eg. on a green fielddevelopment) it can be designed to accommodate the BEMS requirementsand installed by the SCS installer.

Other benefits of using the IT network are shared network maintenancecosts, access to a robust and industry recognised communication networkand an enhanced network security (faults detected and rectified morequickly than normal BEMS network).

Use of an IT network is likely to be for the major data interconnections such asbetween controllers and the central station. Use of a local BEMS network ismore likely to be cost effective for individual plant controllers.

Radio communications applied to BEMS are very limited but offer potential forfuture growth. It has been successfully adopted on large MOD sites such asoperational RAF stations with considerable distances between buildings, toreduce the need for cable links. The technology can be applied both internallybetween field devices and associated outstations and externally over a campustype environment for communications between remote buildings. Security ofradio communication systems may not be satisfactory for particular locations.

2.9 SOFTWARE

The software elements of a BEMS determine how the controls and monitoringfunctions built into it will operate and communicate. This level of software maybe termed the 'firmware' since they can be fixed components of the system whoseoperating parameters and characteristics are set up to match the specificrequirements. The BSRIA Library of Control Strategies provides a set ofstandards. Individual suppliers may opt for particular ways to achieve eachstrategy.

BEMS software imposed above the control strategies provides the monitoringand reporting structure of the system, including how and what reports, alarmsand historical logs are generated.

Documentation for both the firmware and software is critical because it willdefine how each controller and control parameter has been configured, howinformation is stored and reports are generated.

Software protection in terms of licence agreements needs to be resolved at anearly stage of the project. Copies of the software should be held in securelocations, ideally both on and off site.

2.10 STANDARDS AND REGULATIONS

BEMS installations must comply with all relevant statutory regulations. Otherguidance in terms of standards and codes of practice should also be noted.Examples of these are British Standards Codes of Practice and MOD guidance.

The following is a general list of some areas that should be addressed wheninstalling a BEMS:

January 2001 17

a safe means of access for maintenanceall BEMS panels are secured to prevent unauthorised accessthe central station and controllers are password protected to preventunauthorised access


sufficient illumination is provided as required for user operation of BEMSwhere they are situated in plant rooms. This may require additional tasklighting.electrical installations comply with BS7671 1992 - Requirements forElectrical Installations (IEE Wiring Regulations 16th Edition). Commonlyknown as the Wiring Reg'sall equipment complies with the standards relating to electromagneticinterference and is suitable for the particular applicationworkstations comply with the Health and Safety (Display ScreenEquipment) Regulations 1992specific security needs for the particular application relating to hardware,software, sensors and other electronic and IT equipment are followed.

2.11 COPYRIGHT

For a particular application, the detailed BEMS specification, softwareconfiguration, operating parameters and reporting structures established for thespecific application will all be covered by MOD copyright and not, therefore,available to others without authorised agreement.

18 January 2001


3 Installation, Commissioning,Performance Testing

3.1 INSTALLATION

This is the process of translating the requirements set out in the specificationinto a physically completed system (static completion). It requires labour,materials, supervision, inspection, testing and documentation.

In a new installation the plant and equipment needing interconnection with theBEMS should have suitable facilities already available. For existing plant andequipment, where a new BEMS is being installed, there may be a need to replaceor refurbish existing control devices such as sensors, actuators and analoguecontrols.

Installation standards should be defined in the specification, including those fordata cabling, programming, testing, documentation and cable identification.

The installation of a BEMS can be critical to its effective and efficientperformance. It is advised that installation should only be carried out, or closelymanaged, by specialist BEMS installers, or organisations who can demonstratetheir particular expertise in this field.

Safety and operational interlocks are likely to be included within the specificcontrol strategies. These need to be identified in schedule format and proved tobe working in a safe and correct manner. The BEMS would normally onlymonitor the action of such interlocks, particularly for critical operations.

Tests to confirm an installation has been completed and approved to thesatisfaction of the Project Manager should include:

• an audit of the cabling and hardware

• demonstration of the physical and logical integrity of the system

• demonstration of all the control actions

• demonstration of all the sensor calibrations

• demonstration of the system software

• demonstration of the system graphics

• all documentation including drawings and operating and maintenancemanuals have been provided.

January 2001 19

DMG 22 Section 3 Installation, Commissioning, Performance TestingBuilding Energy ManagementSystems

3.2 COMMISSIONING

Commissioning is the process of turning a physically completed system into afully operational working system that meets the designed requirements. Poorcommissioning is the most common cause of BEMS failing to meet the initialperformance expectations. This in turn can lead to unstable and underperforming plant. Suppliers can benefit from good commissioning sincesubsequent warranty costs are likely to be less than for a poorly commissionedinstallation.

A comprehensive specification supplemented with flow diagrams can form thebasis of the commissioning checklist and serve as a yardstick to test the BEMScontrol strategies. It is beneficial to specify as much off-site testing as possible(eg. control panels, application software and graphics) when conditions are moresuitable for testing and remedial work.

Once installed, the BEMS should be fully pre-commissioned as far aspossible,(eg. data cabling interconnections, validity of sensor readings, actuatorperformance). All controls are likely to be needed in 'manual' operation duringfull commissioning of the engineering services. The BEMS can then beintegrated with the building services and finally commissioned and put intooperation. Adequate time needs to be allowed for this, as a guide 30 minutes foreach BEMS sensing point should be anticipated. Attendance will also be requiredby other trades and this should be reflected in the tender figures as part of thecommissioning costs.

On sites where the BEMS is commissioned and handed over in stages, thesensors in the earliest stages may have drifted from the calibration setting bythe time that later stages are commissioned.

Where the BEMS is being installed in an operational building, careful planningis needed to maintain all services so that they continue to function during thecommissioning process.

Whilst the initial commissioning will be carried out to the original design data, itis likely that fine tuning of the system will be required over the first full year ofbuilding occupation to fully meet the requirements of the building operator andthe occupants. It may be appropriate to include this in the original contract cost,particularly for more complex installations. This will lead to greater savings asthe BEMS operation and performance parameters can be optimised. Liaisonbetween the building user/operator and the installation contractor during theperiod of fine tuning is important to ensure a full understanding of how thebuilding is required to function.

BSRIA Application Handbook AH 2/92, Commissioning of BEMS, provides a codeof practice including detailed check lists. Other relevant publications are:

20 January 2001

Commissioning HVAC Systems - Divisions of Responsibilities.

The Commissioning of Air Systems in Buildings

The Commissioning of Water Systems in Buildings

A Procedure for Commissioning VAV Systems

Commissioning of VAV systems in buildings

Commissioning Code C Automatic Control

TM1/88

AG3/89.1

AG2/89.1

TM2/88

AG1/91

BSRIA

CIBSE


Performance testing addresses the operation of the BEMS and the associatedplant. It is aimed at ensuring both are operating in an optimum manner interms of energy and internal environmental performance.

The BEMS operator should be trained to monitor the BEMS performance and tonote and respond to feedback from the building occupants.

Many BEMS receive little or no maintenance. Possibly this is because a BEMS isperceived as microprocessor based and not requiring attention. A BEMS is morethan the central station or controllers. Sensors can go out of calibration,actuators can fail to operate. Building use will change over time, needing setpoints to be revised. Performance testing will detect changes to the BEMS levelof performance and faults due to incomplete commissioning.

Reasons for performance testing include:

January 2001 21

occupant complaints about the environment

energy performance is unsatisfactory

system neglect

little information may be available about the installed control regimes

BEMS performance is inadequate/not satisfactory

unsatisfactory environmental performance

significant change to energy consumption

to evaluate BEMS performance

repeated failures or alarms need to be investigated.

fits of performance testing are:

improved occupant comfort

prevents complaints arising from occupants

energy savings

reduced false alarms

improved awareness of BEMS and control strategies

confidence in BEMS records.

BSRIA Application Guide AG2/94 - BEMS, Performance Testing, providesguidance on a general performance audit and help in resolving particular BEMSproblems.

Guidance on energy consumption benchmarks for MOD buildings can be foundin the DETR Energy Conservation Guide 75 - Energy Use in Ministry of DefenceEstablishments. A copy of the summary page giving the benchmark figures fromthis document is given in Annex D.

Section 3 Installation, Commissioning, Performance Testing

Section 3 Installation, Commissioning, Performance Testing

3.3 DRAWINGS AND DOCUMENTATION

Comprehensive and accurate record drawings and documentation are essentialfor the satisfactory operation and maintenance of a BEMS. These should include:

• BEMS Performance Specification

• written description of plant and how it is controlled

• control strategy, including diagrams

• operating and maintenance manual

• maintenance schedules

• central station software manual

• points list (all analogue and digital inputs and outputs)

• flow diagram

• specifications for sensors and actuators

• schematic wiring diagrams for outstations, field devices and control panels

• controls design specification

• details of set points, alarm levels, time schedules, overload settings

• commissioning data

• plant diagrams showing locations of field devices

• software back-up copies

• emergency procedures

• handover/acceptance documentation

• log book - to record incidents, operational information and all changesmade to the system (para 5.3.1 gives more information about this).

22 January 2001

Building Energy ManagementSystems

DMG 22


4 BEMS Operation

4.1 OPTIONS FOR MANAGING BEMS

To achieve the full benefit of a BEMS installation it will need to be monitored,used and properly maintained rather than simply installed and ignored. Theman/machine interface of a BEMS provides ready access to plant operating data,allows better understanding of the performance of the systems being controlledand helps improve decision making. As such, this interface is a key element ofany BEMS.

Due to the complexities of modern BEMS systems a common problem isidentifying just who is responsible for what and in what context. To helpeliminate this it is recommended that this is agreed and documented at thedesign stage, include operation, access, maintenance and communicationresponsibilities.

It is essential that all personnel authorised to access or use a BEMS areadequately trained to ensure safe and efficient operation of the system. Wherepersonnel have the ability to control or effect equipment or plant controlled bythe BEMS, they must be competent to do so. Risk Assessments and SafetyMethod Statements should be produced and used to ensure safe and correctoperation and use of the BEMS. Individuals with the appropriate authorityshould be able to demonstrate their understanding of the areas within theBEMS to which they have access, and any implications their actions may haverelating to the Health and Safety of both themselves and others.

Authorisation for access to the BEMS or plant rooms in which they may be sited,especially where plant/equipment settings and controls are involved, should beapproved through the Property Manager and managed throughout by theAuthorised Person. In turn the Property Manager should confirm with theEstablishment Works Consultant (EWC) and Works Services Manager (WSM), orrelevant service provider, that the individual requesting use/control of the BEMSis deemed competent for their specific requirements. The EWC and WSM shouldalso be able to confirm if there are any other implications regarding existingmaintenance and operation contracts.

It would be beneficial for the main operators of BEMS to be longer termpersonnel who have a good understanding of the site and any necessaryconditions or concerns. Where this is not appropriate/possible operators can helpby keeping records to pass on. Each new operator should receive full training forthe system.

Having regard to the above, Site Energy Managers would typically be includedin those with access to BEMS at the highest level. This will help ensure

January 2001 23


maximum benefit from the BEMS in terms of energy management, efficiencyand savings. Potential overlap between Site Energy Managers and the WSMmust be discussed and agreed at the earliest stage in the BEMS design. Thismay, for example, lead to siting of BEMS controllers out of plant rooms tofacilitate safe access by the Site Energy Manager.

4.1.1 Examples of the functions of staff who operate and manage BEMS

The hours noted overleaf are illustrative only and will depend on the particularsite and application. Hours do not include for energy Monitoring and Targeting(M&T), or interpretation of consumption information. A BEMS is a tool to aidthe staff listed overleaf. As such, the installation and use of a BEMS, within theroles described, should represent savings in human resources, not demands onthem. This is based on the principle that the BEMS should allow existing tasksto be done in less time. In addition, the improved quality and quantity ofinformation and rapid and flexible control of plant will allow much greatereffectiveness of these tasks.

Site Energy Manager

The typical emphasis of this role regarding BEMS is on improved energyefficiency and management. Typical BEMS use for this role is sevenhours per week. The role may typically include an understanding of howthe engineering plant functions and be aware of the complexities,capabilities and design philosophy of the BEMS. The post holder'sfunctions could include regular checking of plant performance andenvironmental conditions, adjustment of environmental conditions tomeet changes in weather, occupancy or usage and bringing any otherareas of concern to the attention of the Property Manager. The level ofpotential achieved from the BEMS in this role will strongly depend on thelevel of training, understanding, experience and delegated authority totake necessary action.

Site Maintenance Staff/Consultants (Other Service Providers)

The typical emphasis of this role regarding BEMS is on maintenance andoperation of the site infrastructure, without necessarily having anyspecific direction on energy management. Typical BEMS use for this roleis three hours per week. The principle use of the BEMS in this role is toconfirm plant is operating correctly, identify and respond to plant failurealarms and use information for proactive maintenance management. Inmany cases, it will also include operation of plant and equipment. Thisrole requires detailed understanding of how the engineering plantfunctions and all aspects of the BEMS.

Energy Warden (or Building Custodian)

This is often a supporting role to the Site Energy Manager or PropertyManager, normally associated with a single building or small group ofbuildings. Typical BEMS use for this role is up to two hours per week.The role requires ready access to information from the BEMS such astime / environmental settings and actual conditions for the relevantarea(s). Any anomalies can then be manually verified or investigated asrequired and recommendations made or action taken using localknowledge. A basic understanding of the relevant functions andcapabilities of the BEMS would be beneficial. This role does not normallyhave authority for any control function but may have access for limitedadjustment to environmental set points.

24 January 2001

Section 4 BEMS Operation


Property Manager/EWC (Management)

This role primarily requires access to information from the BEMS to aidin the management role or provide clear and rapid understanding ofrelevant systems through the schematics. Use is dependent onrequirement. Typical BEMS use would be up to one hour a week. Only abasic understanding of the plant or BEMS function or capability isrequired. This role would not normally access the control functions. Fullunderstanding of plant or BEMS functions or access to the controlfunctions would be achieved through the Site Energy Manager, WSM orEWC, as required.

4.1.2 Other Options

A Bureau Service could be used to provide 24 hour monitoring of BEMS alarmsremote from the site. There may be scope for this function to be provided by thesite security organisation when the maintenance contractor is not in attendance.Instructions on how to respond to each alarm type or priority level would need tobe established along with contact details for unexpected situations. Maintenancecontractors and other commercial organisations often provide such a facility, at acost, if required.

A more effective use of a Bureau Service would be to audit the BEMSperformance, rather than only provide a reactive alarm monitoring function.This would require the Bureau Service to have skilled and experienced staff whocould interrogate the BEMS, interpret the results and monitor that appropriateaction had been taken. As such, this role would not be suitable for site securitystaff.

Use of a Bureau Service would need to be considered in relation to the existingcontractual arrangements to determine whether scope is available for this.

Another option would be to use the enthusiasm and expertise of existing SiteEnergy Managers by extending their role and responsibility across a number ofsites. Dependent on site sizes, one Site Energy Manager could potentially haveresponsibility for several sites if linked through a suitable communicationnetwork. The BEMS at each location would provide local control and reporting.The Site Energy Manager would interpret the data and, from intimateknowledge of the sites, be able to initiate the appropriate action. This rolewould be further enhanced by access to a comprehensive energy M&T system.

4.2 OUTLINE SPECIFICATION FOR LEVELS OF BEMS OPERATOR

To provide a better understanding of the different potential operating roles ofBEMS, the following four categories show typical aspects of various levels andtypical posts in which they would be suited. Important Note: Any adjustments,control function or accessibility to BEMS plant should be approved in writing bythe Property Manager. This should detail the specific tasks and level ofcontrolability to be authorised including the name(s) of the individual(s) beinggiven the authority. These levels are generic and actual allocation of roles andresponsibilities would benefit from input by experienced personnel.

Level One - typically fits within the role of Energy Warden and may include/require:

• basic understanding of BEMS purpose and method of beneficial operation

January 2001 25



• no or very limited permission to make alterations to set points

• ability to call-up and view data from schematics and points list

• ability and access to view and interpret trend logs for relevant areas

• access to pertinent limited areas of the site only.

Level Two - typically fits within the role of the Property Manager or otherManagers and may include/require:

• as Level One above but also requires access to information and data forthe whole site. Not normally permitted to make alterations to set points.

Level Three - typically fits within the role of the WSM, EWC or other similarservice provider organisations and may include/require:

• a detailed understanding and knowledge of all aspects of the BEMS required

• a detailed understanding and knowledge of all plant integrated with theBEMS. Able to call up and view point data from schematics and pointslist for whole site

• full access to all control functions, liaison with Site Energy Manager,advised if environmental set points or time setting to be altered

• ability and access to acknowledge system alarms

• ability and access to add analogue and digital inputs and outputs to thesystem

• ability and access to change control strategies

• ability and access to view trend logs.

Level Four - typically fits within the role of the Site Energy Manager and mayinclude/require:

• a full understanding of the BEMS architecture, design philosophy andcapabilities

• a full understanding of the functions of the engineering systemscontrolled by the BEMS

• access and ability to call up and view point data from schematics andpoints lists for the whole site

• access and ability to view all system data and set up trend logs orexception alarms

• visibility of all system alarms for relay on to relevant maintenancepersonnel

• access and ability to make changes to time and occupancy controls andset points and alarms

• ability and access to add or change graphics

• ability to change control strategies and add analogue and digital inputsand outputs to the system.

These four levels are only indicative and the particular site and its requirementswill dictate those appropriate. In some instances, levels may be combined, inothers, sub-levels within those shown may be created.

26 January 2001



4.3 TRAINING

To obtain the full benefit of a BEMS it is essential that people who areauthorised to use, operate and maintain it, are trained to allow them to have agood understanding of its capabilities, purpose and potential. Such trainingneeds to be an ongoing process.

Operators need to understand the prime function of the BEMS, which may havechanged since the original design specification was produced. They also need tobe trained in the operating method of the system. Problems that may arise whenestablished procedures are not followed should be part of the trainingprogramme. The procedure for making changes, alterations or additions to theBEMS should already be defined, but will need to be explained, together withhow to record system malfunctions or concerns about incorrect performance toenable them to be resolved by the maintainer.

BEMS operators will need to be trained to understand the displays, how tomonitor and change time schedules, set points and environmental controlsettings, acknowledge and cancel alarms and take action following alarmmessages. They should also be able to carry out routine maintenance of thesystem central station hardware (eg. replace printer cartridge).

Maintenance staff require training in any specialist procedures related to thespecific installation. They also need to understand the generic requirements setout in the HVCA maintenance schedules for BEMS. (See Section 5.3).

4.4 COSTS OF OPERATING BEMS

These can be divided into two elements. The first is maintenance of the installedequipment. An indicative annual cost for this is some 7% of the original installedcost for the complete controls installation. However, the controls components(sensors, actuators, controllers etc.) will need to be maintained in any event. Thecost of maintenance of the BEMS components (ie. control operator station andcommunications network) should be identified separately. In the absence ofother information, a value of 0.5% of the total installed cost could be considered.This value is included within the 7% stated above (see 5.2 Maintenance Costs).

The second element is the operator cost for the system. This will depend on therole of the person acting in this capacity, and whether energy M&T is included.For BEMS operation, an indicative figure of 10% - 20% full time attendancewould need to be available for this role. Should energy M&T also be included,the time proportion increases to 30% - 40%.

4.5 UPGRADING AND REFURBISHMENT OF BEMS

The cost of upgrading or refurbishment of BEMS will need to be demonstrated tobe cost effective. Anticipated energy savings are likely to be the principlejustification, though other potential advantages, listed in para 1.5, may also beappropriate. A life cycle cost analysis showing anticipated operating,maintenance and repair costs of the existing equipment, compared with the costof upgrade or refurbishment, over say 15 years, can help to make the case.

At the design stage, adequate spare capacity should be provided in the systemfor known or anticipated system expansion. This extra capacity needs to beavailable at the central station, outstations and the communications network.

January 2001 27



Specific site requirements and known proposals should be used as the basis forexpansion planning. However, in the absence of detailed information anallowance of 20% should be made in each of the component elements withpotential for expansion such as the central station, outstations andcommunication network.

If the BEMS is a modular system, it may be reasonable to provide minimalexpansion capability during the initial installation and provide additionalmodules when required.

When upgrading an existing system, the initial consideration is likely to be touse the same equipment supplier. This should avoid problems with thecommunication standards protocols and interfaces between different suppliers'equipment. The age, reliability and performance of an existing system mayinfluence the decision to continue with the same supplier.

When an existing BEMS has insufficient capacity to upgrade to meet currentrequirements, it may be practical to retain field devices and the communicationnetwork to limit the project cost. It is possible that the existing equipment froma particular supplier may not be compatible with their current product range.BEMS equipment suppliers claim to be able to interface with the majority ofcompetitors equipment. Careful programming of the project will be required toensure all systems are operational during the upgrading.

CIBSE have published the following economic life factors for BEMS components,which may be useful when considering upgrading or refurbishment. The specificapplications and quality of maintenance will dictate the remaining life ofexisting components.

Equipment Item Typical LifeFactors (Years)

BEMS operating system 5-10

AutoDial modem 5-10

Communication network (hardwiring) 25-30

Network communications services 10-15

Damper actuators 10-15

Outstations 5-15

Sensors 3-10

Control valves 15-20

Control dampers 15-20

Utility sub-metering 10-20

Electronic controls 12-18

Hydraulic valve actuators 10-15

Pneumatic valve actuators 15-20

28 January 2001



5 BEMS Maintenance

5.1 PREAMBLE

With the increasing complexity of BEMS it is essential that their integrity(including software and applications) is checked and the requirements reviewedat regular intervals. Ignorance of a system's capabilities, coupled with poorcommissioning and lack of client commitment can result in a BEMS becoming anexpensive time clock.

If the equipment is not correctly and fully commissioned and maintained byspecialist, trained personnel and supported by the manufacturers, the benefits ofthe investment will be lost, energy wasted and operational costs will rise.

Where a BEMS is installed, the client should be aware of the need forcontinuous monitoring of performance. Switching off because of a malfunction orlack of data update can negate the considerable investment and give rise tounacceptable environmental conditions and energy wastage.

Building operators with a BEMS should ensure that the operators have hadappropriate training to understand the equipment and carry out routine dailyand weekly maintenance tasks, such as monitoring and changing timeschedules, set points, environmental control settings and simple computerhardware maintenance (eg. changing printer cartridges). Such training needs tobe an ongoing process.

5.2 MAINTENANCE COSTS

It is essential to make provision for the ongoing maintenance of a BEMS once itis installed. As a budget indicator, an annual cost of 7% of the installed cost (ie.the hardware, software, outstations, sensors and actuators, and communicationinterfaces) should be allowed for the complete controls installation. This figurehas been obtained from suppliers, BEMS specialist maintenance contractors andMOD users. This would cover, depending on the size of the installation,maintenance of the central operator station, data communications, controllersand software functions, calibration of sensors, and operational checks ofactuators. Spare parts and replacements would be additional costs. As noted inpara 4.4, Costs of Operating BEMS, the maintenance of the BEMS componentsis a small proportion of the 7% figure.

5.3 CONTRACT ARRANGEMENTS

The HVCA have produced a series of standard maintenance specifications formechanical services in buildings. Volume III covers Control, Energy and

January 2001 29

DMG 22Building Energy Management Section 5 BEMS MaintenanceSystems

Building Energy Management Systems. The HVCA Standard can be used as ameans of checking that work has been carried out and conforms to therequirements. It is essential that the specialist engineer appointed for BEMSmaintenance is familiar with the equipment and the manufacturer'smaintenance manual.

Maintenance schedule or contract needs to be in place from the date the BEMSis handed over to the client. One option for the initial twelve month period is toinclude the cost in the supply contract. If this is done, the cost details need to beseparately identified in the tender document.

Contract options are:

• direct contract to specialist or equipment supplier

• arrange call-out facility only with specialist or supplier

• place BEMS maintenance through main M&E maintenance contractor.

Details of the arrangement also need to be addressed, such as minimum call-outresponse time, whether a fully comprehensive contract is required (ie. costsinclude all spares, consumables, and replacement following breakdown).

Maintenance contractors undertaking BEMS maintenance should havespecialists with:

• necessary training

• knowledge of the installed system

• up-to-date awareness of manufacturers equipment

• access to up-to-date diagnostic equipment

• good technical support

• access to good stocks of spares.

5.3.1 Operating and Maintenance Documentation

It is essential that a detailed manual be kept on site. This site manual recordsthe responsibilities of all parties involved with the BEMS, together with theinstalled equipment, normal settings, control diagrams and location of theOperating and Maintenance manual relating to the specific plant and controlequipment. This site manual can also serve as a service log to record faults and

observed by the BEMS operator, changes to control parameters, setpoints, program algorithms plus reasons why the change was necessary. It canalso be used to check when each entry is resolved.

5.4 SPARES AND CONSUMABLES

Investigation of typical BEMS installations at various MOD locations indicatedthat spares and consumables may not need to be stored on site, as they are oftenreadily available from manufacturers and could be charged for on an 'asrequired' basis.

30 January 2001

DMG 22Building Energy Management Section 5 BEMS MaintenanceSystems

Therefore, it is not recommended that BEMS spares be held on site unlessparticular requirements such as equipment serving a strategically essentialsystem justify this.

Items which are known to be regularly replaced such as sensors, valves andactuators, which are common throughout the site, would justify being held atminimum levels to allow replacement to be carried out.

5.5 RECOMMISSIONING

Over time, BEMS settings, performance and operating parameters will changeas items become worn, electrical items drift and other circumstances change.

Regular recommissioning of the BEMS can help ensure it is operating at its fullpotential, maximum energy savings are being achieved and plant performanceand expected life is maximised. The frequency and areas of the BEMS forrecommissioning should be based on regular monitoring of the BEMSperformance and any major changes in the use or layout of the areas beingmanaged by it.

An indicative cost for recommissioning should be based on around 30 minutesper point to be covered.

January 2001 31

32 January 2001


Figure 4Energy monitoring andtargeting

6 Energy monitoring and targeting

6.1 REVIEW AND RELATIONSHIP WITH BEMS

A target can be defined as a measurable objective to be achieved in a given time.In terms of energy management, it may be a forecast over a twelve month periodof the expected utility consumption eg. electricity, gas, oil, water. For heating,cooling and lighting loads, there will be fluctuations over the twelve monthperiod due to variations in external weather conditions and the available hoursof daylight. This is in addition to the specific building requirements such aschanges in the hours of occupancy.

Figure 4 shows an example target consumption for an office type building, with atolerance margin around the target line of ±10% to show acceptable performancecriteria.

7000

6000

5000

4000

3000

2000

1000

0

By plotting the actual consumption on the target graph on say, a monthly basis,a good indication of performance against target can be obtained, as shown by thewhite line. As weather conditions are never the same year to year, or even monthto month, the results may need to be normalised by the use of degree-dayinformation. This provides detailed meteorological information of the days whenheating (or cooling) would have been required, which allows target informationto be modified to actual local weather conditions.

January 2001 33

Target Consumption

Target ±10%

Actual Consumption

DMG 22Building Energy Management Section 6 Energy monitoring and targetingSystems

An alternative method for establishing a target is to monitor consumption oversay, a twelve month period. Potential energy savings can then be identified andenergy targets set.

Comparison of actual performance (or the current performance) against thetarget is called monitoring. The process of energy M&T allows regular (eg.monthly) comparisons of actual energy use to be made against planned orbudgeted data, to identify if problems are becoming apparent. It can also allowperformance of similar buildings to be analysed. Statistical data on thecumulative energy consumption figures allow trends to be obtained.

To put M&T of energy consumption into practice requires regular and reliableinformation to be available. One means of obtaining this data would be to read itfrom utility bills, another would be to physically visit local supply meters andrecord information. Utility bills are not always based on site visits (ie. thereading may be estimated) and the periods between readings may not beconsistent (eg. three weeks or five weeks for monthly readings). Use of local staffto take readings can generate inaccurate information due to difficulties ormisunderstandings when reading the meter. The labour cost can also beexpensive.

A BEMS can provide a relatively cheap and powerful tool to obtain the energyconsumption data by logging it directly from a suitable meter. This can provide acontinuous information stream of very accurate data and any required time basecan be used to analyse it. Analysis against local weather conditions to makedegree day comparisons is also feasible by introducing suitable external sensorsand software. The consumption data can be used to compare data on utility bills.

Some BEMS suppliers have M&T software available which is appropriate for alimited number of metering points. If the number of metered points exceedsabout 20 and detailed analysis and interpretation of the data is required,specialist software becomes more appropriate.

Separate M&T software is required to analyse and report on the data availablefrom the BEMS to use it to its maximum advantage. Considerable effort isrequired to interrogate large volumes of data. The software should ideallyprovide graphical output as shown in Fig 4 to visually demonstrate performance.Also, there should be a capability to generate exception reports so that routineanalysis of the meter data is being carried out and warnings are only flagged upwhen the readings are outside pre-set limits, indicating a more in-depthinvestigation is required.

6.2 ADVANTAGES AND POTENTIAL COST SAVINGS

As identified above, by using a BEMS to interrogate and log data from utilitysupply meters, it becomes possible and practical to process large volumes ofinformation.

The BEMS communication system can be used to automatically collect, inputand analyse information from utility meters for an M&T System. This canprovide significant resource savings where this information is currently collectedand input manually. In addition the frequency of reading and hence quality ofinformation from automated meter reading can be vastly superior to manualcollection. Occasional manual reading of meters is still recommended to verifyany spurious readings and provide confidence in the information provided.

34 January 2001


Once targets have been established, actual energy consumption can beeconomically monitored. The process of monitoring can highlight areas of energywaste, where savings can be made, such as inaccurate time controls needing tobe re-set.

The ready availability of energy consumption data can allow performance to bemeasured over time, producing trend logs that can be used to identify abnormalpeaks or troughs in consumption. The data can also be used to compare withother published reference information.

Publication of monitoring information against target can provide a useful focusfor building occupants to concentrate attention on energy savings.

The availability of utility consumption data is a useful tool for checking utilitybills. Billing inaccuracies have been highlighted by comparison with BEMSrecords and significant overpayments recovered after representation to theutility suppliers.

Closer attention to utility use and consumption can also generate savings byanalysis of the fuel supply tariff or contract, particularly if this has not beenreviewed for some time. Utility monitoring can help to indicate whether there isabnormal use (eg. heavy consumption overnight when utility use should beminimal). This could suggest a leak in the supply or distribution system. It couldalso mean there is a fault with the meter.

Savings of between 5% and 15% of utility supply costs have been achieved byrigorous application of an M&T system due to the continuous control andmanagement of consumption. These results only continue to be achieved by theongoing implementation of energy M&T. One feature of many successfulsystems is that target performance figures are reviewed and tightened on anannual basis.

6.3 COST IMPLICATIONS

Software costs for energy M&T can range from £1500 to £7000, depending on thereporting and analysis capability being provided.

The hardware for this application could be the head end of the BEMS, or it maybe felt appropriate to have a separate, dedicated PC to avoid losing the systemmonitoring capability of the BEMS head end. The processing capability requiredfor analysing the monitoring and targeting data can also justify a separate PC inaddition to the BEMS head end machine.

Suitable utility meters need to be available which will provide a pulsed signal tothe BEMS. If these do not already exist there can be significant costs in theirpurchase and installation, together with their interconnection to the BEMSusing dedicated communication cabling or interfacing with an existing datanetwork. When main incoming supply meters, belonging to the supply authority,are involved there can be a cost of up to £1000 for initial provision together withan annual maintenance charge to ensure their accuracy.

For larger sites, existing metering arrangements for main incoming utilitymeters may already be providing suitable data for detailed energy monitoring.The utility supplier or meter operator will be able to provide further details.

In addition, allowance needs to be made for customising the software to theparticular application. An indicative cost for this, based on two man days work,would be £1000.

January 2001 35


Once the system is in place and fully operational, it needs to be administered. Anindicative allowance for larger sites would be one man day per week to collatethe data, interpret system reports, initiate and monitor actions, investigatequeries and produce summary energy management reports.

The CIBSE Guide 'Energy Efficiency in Buildings' suggests that a manual M&Tsystem may be suitable for a building with an energy bill less than £10,000 pa,and could cover invoice checking, monthly energy consumption plotting andcomparisons with consumption in previous years.

On buildings or sites with energy consumption up to £100,000 pa, the Guidesuggests a simple spreadsheet may be more appropriate for M&T. For sites andbuildings with annual energy bills over £100,000 it is suggested an M&Tsoftware package may be a more appropriate approach.

36 January 2001


Annex A - Typical costs and savingsassociated with BEMS

TYPICAL COSTS AND SAVINGS ASSOCIATED WITH BEMS

Scoping study - Provides framework and Limit of Liabilityfor an Option Study. (Completion of this table will help inassessing initial feasibility and whether to proceed toscoping study stage. Completion at Annex A will help indefining the BEMS requirements.)

Staff resources to produce the specific specification.(See Paragraphs 2.5.2, 2.5.3 and Annex A.)

Full Option Study - Reviews the options, including donothing and provides recommendations and costs for themost suitable way forward. (Use this guide, Specification47, and other extant documentation or Defence Estates toprovide guidance).

Planning, installation and commissioning costs. Rememberto given an allowance for the increased useful life betweenany new equipment against old equipment replaced as aresult of BEMS installation. (See Paragraphs 2.1, 2.9 and 4.5).

Additional costs for energy Monitoring and Targeting systemif required. (See Section 6)

Manpower saved by automated meter reading and dataprocessing if appropriate. (See Paragraph 6.2)

Annual general maintenance costs over and above those forstandard controls. (See Paragraph 4.4)

Resource savings through being able to do previous tasks inless time. (See Executive Summary, Paragraphs 1.3, 1.5and 2.3)

Initial training costs. (See Paragraph 4.3)

Plant and maintenance savings through greater ability toplan, manage and implement maintenance. (See ExecutiveSummary, Paragraphs 1.3, 1.5 and 2.3)

Greater flexibility and control of building services allowingproactive and greater response speed to occupants needs.(See Executive Summary, Paragraphs 1.3, 1.5 and 2.3)

January 2001 37


Annex A Typical costs and savings associated with BEMS

TYPICAL COSTS AND SAVINGS ASSOCIATED WITH BEMS (CONT'D)

Ongoing training costs. (See Paragraph 4.3)

Standing cost from communications such as telephone linerental. (See paragraph 2.7)

Software maintenance / upgrade costs.

Energy savings from improved building services control.(See Paragraph 2.3)

Recommissioning costs as / if required. (See Paragraph 5.5)

Any additional site specific costs or savings

Totals (Note: Take costs over the life of the system)

38 January 2001


Annex B - Analysis of Requirements

Location(s) covered by this project.

Is there an operational requirement forcentral monitoring or control?

Is there an existing BEMS?

Is an existing communication networkavailable?

Can existing controls be operated andmaintained?

Have good housekeeping measures beenapplied?

Are building occupants satisfied withtheir environment?

Is there an opportunity to integratecontrols of different engineering services?

Has the building function changed sinceBEMS installed?

Is a central station(s) required?

If yes, state location.

List operational plant in each building tobe connected to BEMS (use Pro FormaOne).

State site energy management procedures.

Are these to integrate with BEMS?

If yes, state how.

Does energy use compare with publishedguidelines?

Is it required to recharge buildingoccupants for energy?

Are consumption records needed for tariffanalysis?

Are any locations subject to development?

If yes, is BEMS design to include thedevelopment?

January 2001 39



Is a 'portable keyboard' acceptable toaccess BEMS?

Will security/reception staff operateBEMS?

Will dynamic display of plant and systemlayouts be required?

Project Ref.

Prepared By Date

Yes

Yes

Yes

No

No

No

40 January 2001



PRO FORMA ONE

Project

Prepared by

Building reference

Date

Heating plantHeatingdistribution

Cooling plant

Coolingdistribution

Ventilation -supplyVentilation -extract

Toilet extractKitchen extract

Car park extractSmoke extract/controlFume cupboardextractFume extract

Airconditioning

Air curtain

Hot and coldwater services

Electricalsupply

Electricaldistribution

Standbygeneration

UPSGenerallighting

Emergencylighting

External lighting

Security/accessFire detection/alarm

Lifts/escalators

Catering

Other

January 2001 41

Operationalplant to beconnected toBEMS

Monitor Control Operate EnergyM&T

ImportanceHigh = 3Med. = 2Low = 1

BEMS notrequired

42 January 2001


Annex C - Tender Summary

(Minimum breakdown of Tender Return to allow detailed analysis)

Item Cost

1 Site Investigations

2 System Design

3 Hardware

3a Central supervisor

3b Controllers

3c Unitary controllers

3d Sensors

3e Actuators

4 Communication network

5 Software

6 Graphics

7 Installation

8 Testing

9 Commissioning

10 Training

11 Drawing and

12 Energy monitoring and targeting

13 Twelve month maintenance from date of handover

January 2001 43


44 January 2001

Annex C Tender Summary


Annex D — Energy consumptionbenchmarks for MOD buildings

Fossil fuelbenchmark(kWh/m2

/annum)

11095

143

133250360775

225

175

317

18754

444315220100

0

235

114334123

Electricitybenchmark(kWh/m2

/annum)

315460

2779

150165

29

29

20

343

21122399

75

158836

Totalbenchmark(kWh/m2

/annum)

141149203

160329510940

254

204

337

22157

465327243109

9

310

129422159

January 2001 45

Offices

Sports & recreationfacility

Multi-occupancyaccommodation

Workshops

Motor transportfacilities

Stores/warehouses

Hangers

Messes with integralaccommodation

Training/education

Category

123

1234

12

12345

123


Annex D Energy Consumption Benchmarks for MOD Buildings

Definition of Categories(for full explanation see ENERGY CONSUMPTION GUIDE 75 - Energy use inMinistry of Defence Establishments - details on how to obtain this Guide aregiven in Technical Bulletin 99/27)

Offices

Sports & recreation facility

Stores/warehouses

Hangers

Training/education

Category

1 Naturally ventilated, cellular2 Naturally ventilated, open plan3 Natural/forced ventilation and some

comfort cooling

1 Dry sports facility - small2 Dry sports facility (without pool) - large3 Sports facility with pool4 Swimming pool only (no sports hall)

1 Occupied2 Unoccupied

1 Heated and uninsulated2 Low heating and uninsulated3 Heated, insulated, refurbished4 Very low heating or store with low activity5 Unheated

1 Naturally ventilated lecture rooms2 Forced ventilated lecture rooms3 Technology training facilities

46 January 2001


Glossary of Terms Associated with BEMS(Generally derived from BSRIA Standard Specification for BEMS)

access timeTime interval between therequest for information atthe central station andwhen it is available

access controlMeans for limiting accesswithin security controlledarea to those withauthorised identification

actuatorA device for turning acontrol signal into aphysical control action

adaptive controlAutomatic change ofcontrol parameters toachieve optimum systemperformance

alarmAudible or visualindication of a dangerousor undesirable condition

algorithmA finite set of well definedrules or series ofinstructions or proceduralsteps for the solution of aspecific problem or controlof a particular item ofplant

Relating to data thatconsists of continuouslyvariable quantities

boiler compensationChanging boiler operatingtemperature in relation tooutside temperature

boost periodPeriod immediately priorto occupancy periodduring which heatingplant is operating at fullcapacity

BUSCable connected to devicessuch as sensors, actuatorsand outstations providingdata communication route

central stationPrimary point of access tothe BEMS and usualpoint from whereoperation is supervised

commissioningAdvancement of aninstalled system to fullworking order inaccordance with thespecified requirements

compensatorControl device whichreduces heat supply asbuilding heat loadreduces, possibly inresponse to outsidetemperature

configuration softwareSoftware (in the form of"building blocks") residentin an outstation whichcan be configured tocreate different controlstrategies

control algorithmSee Algorithm

control functionTerm describing the formof control

controller (outstation)A device to which sensorsand actuators areconnected which providesmonitoring and/or controlof the building servicesfunctions. It also has thecapacity to exchangeinformation within thesystem

control pointPre-selected variable suchas desired internaltemperature

control strategyLogical steps used tocontrol an item of planttogether with set pointsand operating parameters

default valueA reserved value or optionused when no other isspecified

degree dayA means of comparingvariations of heatingrequirements in differentparts of the country,normally based on thedaily difference in basetemperature of 15.5°C andthe 24 hours mean outsidetemperature (CIBSEGuide B.18)

digitalRepresentation of a valueby discreetly variablephysical quantities

direct digital controlTerm used to indicate thatplant is under the directcontrol of software in aBEMS outstation orcentral station and notthrough the intermediaryof some stand alone non-programmable controller

distributed(or distributed intelligencecontrol) control BEMSsystem where processingis carried out atcontrollers (or outstations)as well as the centralstation

duty cyclingAlternating sequence ofplant use to rotateoperating and standbyplant

EMCElectro magnetic current

energy targetDesired total energy usein a building or process

feedback controlClosed loop control wherethe control activatingsignal is derived from theset point and a signalindicating the currentvalue of the controlledmedium

firmwareOperating parameters andcharacteristics of fixedcomponents of a systemset up to provide specificrequirements

47


Glossary

head endSee 'Central Station'

HVACHeating, Ventilation andAir conditioning

iconGraphical symbolindicating an object on avisual display unit

LANLocal Area Network - acabling system withassociated software to linka number of computerbased systems allowingthem to communicate

load cyclingControlling plant outputby fixed on and off periodsof operation

mimic displayA screen based displayrepresenting the HVACsystem in graphicalformat. It will usuallyshow current values andstatus of plant

monitoringProcess of collecting,analysing and reportingdata

networkAn electronic methodconnecting computers andother equipment needingto be limited for the input,output and storage data

night set backRelaxation of maintainedspace conditions by a pre-set amount for theovernight period

outstationSee "Controller"

performancespecificationWritten description ofrequirements for BEMScontrolled plant in termsof physical behaviour orperformance ie.temperature andhumidity limits, zoningtime control, operation ofplant. It does not specifydesign of BEMS. Usuallywritten by consultants

set pointUser defined value of acontrol parameter that anHVAC system strives tomaintain

software licenceAny form of document oragreement which maylimit the client's use of thesoftware resident in theBEMS

SpecificationParticularFull BEMS specificationfor a project comprising:

Standard Specification

Supplementaryspecification for particularBEMS

Standard specification forelectrical installation

Standard specification formechanical installation

trend logA collection of stored datasamples relating to eitherphysical inputs oroutputs, or virtual points.Each sample is collectedat a fixed time intervalfrom the previous samplecollected.

48 January 2001


Bibliography

Standard Specifications for BEMSApplication Handbook AH 1/90

Volume 1 SpecificationVolume 2 Guide

Library of System Control StrategiesApplication Guide 7/98

Commissioning BEMS - a code of practice

BEMS Performance TestingApplication Guide AG 2/94

Standard Maintenance Specification for mechanicalservices and buildings

Volume 3: Control, Energy, BEMS

CIBSE Automatic Controls and their Implicationsfor System Design

CIBSE Commissioning Code C Automatic Control

Specifying Building Management SystemsTechnical Note TIM6/98

Building Energy Management Systems HTM 2005Vol. 1 Management PolicyVol. 2 Design ConsiderationsVol. 3 Validation and VerificationVol. 4 Operational Management

NHS Model Engineering Specification C54Building Energy Management Systems

Installation, commissioning and maintenance offire and security systems

Application handbook AH 3/92Pt. 1 GeneralPt. 2 Fire detectionPt 3 Security systems

Installing BEMS to meet electromagnetic compatibilityrequirements BRE Digest 424

Survey of building and energy management userperceptions

Building Control and Indoor Environmental Quality- A Best Practice Guide

Technical Note TN9/98

BSRIA1990

BSRIA1998

BSRIA1992Application Handbook AH2/92

BSRIA1994

HVCA1992

CIBSE 1985

CIBSE 1973

BSRIA1998

NHS Estates

NHS Estates 1996

BSRIA1992

Building Research Establishment1997

BSERT1996

BSRIA1998

January 2001 49


Bibliography

CIBSE Guide - Energy Efficiency in Buildings

The Future of Building Services Management andControl Systems M. D. Clapp; K. Churches

Building Automation

Building Energy Management Systems

Building Automation

Building Services Net Benefits

Building Management Systems Command andControl

Survey of Building and Energy Management Systems- user perceptions

CEN (European Committee for Standardisation)CEN/TC 247 Building management products andsystems for HVAC applications (Draft)

Investment appraisal and post project evaluation

MOD Guide to Investment Appraisal and Evaluation

Appraisal and Evaluation in Central Government

Through Life Costing

Value Engineering

CIBSE 1998

GEC Review Vol. 8 No. 21993

Electrical Review Vol. 230 No. 3

Energy in Buildings & Industry,September 1995

Australian Refrigeration AirConditioning and Heating, July 1992.

Electrical Review Vol. 230 No. 14

Premises and Facilities ManagementMarch 1991

Proc. CIBSE A: Building ServicesEngineering Research & Technology17(4) 199 - 202 (1996)

January 1999

JSP 41 4 Part 4 Chapter 16

Treasury Guidance (1997)

DEO Technical Bulletin 96/04DEO (Works) 1996

DEO Technical Bulletin 96/03DEO(Works) 1996.

50 January 2001

Documents

DMG 22. Building Energy Management Systemsdocshare01.docshare.tips/files/28817/288178063.pdf · Building energy management systems ... and contractors in execution of contracts for