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2013 edition – for use in England*
Non-Domestic Building Services Compliance Guide
Compliance G
uide N
on-Dom
estic Building Services
O N L I N E V E R S I O N
O N L I N E V E R S I O N
* Note: Any reference to the Building Regulations in this guide is to the Building Regulations 2010 in England (as amended). These Regulations also apply to the following building work in Wales:
(a) work on an excepted energy building as defined in the Schedule to the Welsh Ministers (Transfer of functions) (No 2) Order 2009 (SI 2009/3019); and
(b) work that is subject to provisions of the regulations relating to energy efficiency specified in regulation 34 of the Regulations and is carried out to educational buildings, buildings of statutory undertakers and Crown buildings, or carried out by Crown authorities.
This guidance comes into effect on 6 April 2014. Work started before this date remains subject to the earlier edition of the guidance. Work subject to a building notice, full plans application or initial notice submitted before this date will also remain subject to the earlier edition of the guidance, provided it is started before 6 April 2015.
For other jurisdictions in the UK, it will be necessary to consult their own building regulations and guidance.
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Contents
Contents
Section 1: Introduction 51.1 Scope 5
1.2 Innovativesystems 6
1.3 Europeandirectives 6
1.4 Statusofguide 7
1.5 Howtousethisguide 8
1.6 Keytermsforspaceheatinganddomestichotwatersystems 8
1.7 Summaryofrecommendedminimumenergyefficiencystandards 9
Section 2: Gas, oil and biomass-fired boilers 142.1 Introduction 14
2.2 Scopeofguidance 14
2.3 Keyterms 14
2.4 Determiningboilerseasonalefficiency 16
2.5 Boilersinnewbuildings 19
2.6 Boilersinexistingbuildings 20
2.7 Heatingefficiencycreditsforreplacementboilers 21
2.8 Biomassboilers 24
Section 3: Heat pumps 253.1 Introduction 25
3.2 Scopeofguidance 25
3.3 Keyterms 26
3.4 Heatpumpsinnewandexistingbuildings 26
3.5 Heatingefficiencycreditsforheatpumpsystemsinexistingbuildings 28
3.6 Supplementaryinformation 30
Section 4: Gas and oil-fired warm air heaters 314.1 Introduction 31
4.2 Scopeofguidance 31
4.3 Keyterms 31
4.4 Warmairheatersinnewandexistingbuildings 32
4.5 Heatingefficiencycreditsforwarmairheatersinnewandexistingbuildings 32
* Note: Any reference to the Building Regulations in this guide is to the Building Regulations 2010 in England (as amended). These Regulations also apply to the following building work in Wales:
(a) work on an excepted energy building as defined in the Schedule to the Welsh Ministers (Transfer of functions) (No 2) Order 2009 (SI 2009/3019); and
(b) work that is subject to provisions of the regulations relating to energy efficiency specified in regulation 34 of the Regulations and is carried out to educational buildings, buildings of statutory undertakers and Crown buildings, or carried out by Crown authorities.
This guidance comes into effect on 6 April 2014. Work started before this date remains subject to the earlier edition of the guidance. Work subject to a building notice, full plans application or initial notice submitted before this date will also remain subject to the earlier edition of the guidance, provided it is started before 6 April 2015.
For other jurisdictions in the UK, it will be necessary to consult their own building regulations and guidance.
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Section 5: Gas and oil-fired radiant heaters 345.1 Introduction 34
5.2 Scopeofguidance 34
5.3 Keyterms 34
5.4 Radiantheaters 35
5.5 Heatingefficiencycreditsforradiantheatersinexistingbuildings 35
Section 6: Combined heat and power and community heating 376.1 Introduction 37
6.2 Scopeofguidance 37
6.3 Keyterms 37
6.4 CHPinnewandexistingbuildings 38
6.5 Supplementaryinformation 39
Section 7: Direct electric space heating 407.1 Introduction 40
7.2 Scopeofguidance 40
7.3 Electricspaceheatinginnewandexistingbuildings 40
Section 8: Domestic hot water 438.1 Introduction 43
8.2 Scopeofguidance 43
8.3 Keyterms 44
8.4 Domestichotwatersystemsinnewandexistingbuildings 46
8.5 Supplementaryinformationonelectricwaterheaters 48
8.6 Heatingefficiencycreditsfordomestichotwatersystemsinnewandexistingbuildings 49
Section 9: Comfort cooling 519.1 Introduction 51
9.2 Scopeofguidance 51
9.3 Keyterms 51
9.4 Comfortcoolinginnewandexistingbuildings 52
9.5 CalculatingtheseasonalenergyefficiencyratioforSBEM 53
9.6 Supplementaryinformation 55
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Contents
Section 10: Air distribution 5610.1 Introduction 56
10.2 Scopeofguidance 56
10.3 Keyterms 56
10.4 Airdistributionsystemsinnewandexistingbuildings 57
10.5 Heatrecoveryinairdistributionsystemsinnewandexistingbuildings 61
10.6 CalculatingthespecificfanpowerforSBEM 61
Section 11: Pipework and ductwork insulation 6211.1 Introduction 62
11.2 Scopeofguidance 62
11.3 Insulationofpipesandductsinnewandexistingbuildings 62
Section 12: Lighting 6512.1 Introduction 65
12.2 Scopeofguidance 65
12.3 Keyterms 65
12.4 Lightinginnewandexistingbuildings 66
12.5 LightingEnergyNumericIndicator(LENI) 68
Section 13: Heating and cooling system circulators and water pumps 7113.1 Introduction 71
13.2 Scopeofguidance 71
13.3 Keyterms 71
13.4 Glandlesscirculatorsandwaterpumpsinnewandexistingbuildings 71
13.5 Supplementaryinformation 71
Appendix A: Abbreviations 72
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Section 1: Introduction
Section1: Introduction
1.1 ScopeThisguideprovidesdetailedguidancefortheinstallationoffixedbuildingservicesinnewandexistingnon-domesticbuildingstohelpcompliancewiththeenergyefficiencyrequirementsoftheBuildingRegulations.
Thiseditioncoversthedesign,installationandcommissioningof:
• conventionalmeansofprovidingprimaryspaceheating,domestichotwater,mechanicalventilation,comfortcoolingandinteriorlighting
• lowcarbongenerationofheatbyheatpumpsandcombinedheatandpowersystems.
Theguidesetsoutrecommendedminimumenergyefficiencystandardsforcomponentsofbuildingservicessystems,includingtheuseofcontrols.Forsystemsinstalledinnewbuildings,thestandardsaredesignlimits(orbackstopvalues).Forneworreplacementsystemsandcomponentsinstalledinexistingbuildings,thestandardsrepresentreasonableprovisionforcomplyingwiththeBuildingRegulations.
Itisimportanttonotethatstandardshigherthanmanyoftheserecommendedminimumstandardswillneedtobeachievedif:
• newbuildingsaretomeetthetheBuildingRegulationstargetcarbondioxideemissionrate(TER)calculatedusingNationalCalculationMethodology(NCM)toolssuchasSBEM1
• systems(upto45kWheatoutput)aretocomplywiththeMicrogenerationCertificationSchemestandardsthatenablebuildingownerstoreceivepaymentsundertheRenewableHeatIncentive(RHI)andqualifyforGreenDealfunding
• productsaretoberecognisedasrenewabletechnologiesundertheRenewableEnergyDirective.
Theguideincludessomesupplementaryinformationthatidentifiesgoodpracticedesignandinstallationstandardsthatexceedtheminimumstandardsinthisguide.MicrogenerationCertificationSchemestandards2areanexampleofgoodpracticestandards.
Inrelevantsections,theguideidentifiesadditionalnon-prescriptivemeasures(forexampleadditionalcontrols)thatcanimproveplantefficiency.Thesemaybeusedtogain‘heatingefficiencycredits’tohelpmeetthecarbondioxideemissiontargetsfornewbuildings,ortherecommendedminimumenergyefficiencystandardssetoutinthisguideforworkinexistingbuildings.
AsummaryofrecommendedminimumenergyefficiencystandardsispresentedinTable1attheendofthissection.
1 TheNationalCalculationMethodology(NCM)modellingguideandtheSimplifiedBuildingEnergyModel(SBEM)toolcanbedownloadedfromwww.ncm.bre.co.uk.2 http://www.microgenerationcertification.org/mcs-standards
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1.2 InnovativesystemsItisalsoimportanttonotethatthisguidecoversarangeoffrequentlyoccurringsituations.Itdealswiththemostcommonlyusedfixedbuildingservicestechnologies.IndoingsoitneitherendorsesthesemethodsandtechnologiesnorexcludesothermoreinnovativetechnologiesthatmayofferanalternativemeansofmeetingthefunctionalrequirementsoftheBuildingRegulations.
Wherethealternativetechnologyhasbeenthesubjectofarecognisedtestingprocedurethatassessesitsenergyperformance,thismaybeusedtoindicatethatthesystemisadequatelyefficient.Intheeventthatthereisnorecognisedtestingstandard,suitablecalculationsormodellingmethodsmaybeusedtoshowthecarbonperformanceofthesystem.
1.3 EuropeandirectivesThedesignandinstallationoffixedbuildingservicesproducts,suchasboilers,circulatorsandheatpumps,shallattheappropriatetimecomplywithallrelevantrequirementsofEUdirectivesasimplementedintheUnitedKingdom.Thereareanumberofdirectiveswithrequirementsthatdirectlyorindirectlycontroltheenergyefficiencyofbuildingservices.
TheEcodesign Directive 2009/125/ECprovidesaframeworkforestablishingrequirementsfor‘energy-related’productsplacedontheEUmarket.Currentrequirementscover‘energy-using’productssuchasboilers,lightbulbsandwashingmachines.Inthefuture,requirementswillalsocoverproductssuchaswindows,insulationmaterialandshowerheadswhoseusehasanimpactonenergyconsumption.
TherequirementsaresetoutinCommissionRegulationslistedinthedocumenthttp://ec.europa.eu/energy/efficiency/ecodesign/doc/overview_legislation_eco-design.pdf.ProductscoveredbytheregulationscanonlybeCEmarkedandplacedonthemarketiftheymeettheecodesignstandardsspecified.
Atthetimeofpreparationofthisguide,CommissionRegulationsexistedorwerebeingdevelopedfor:
• spaceheatersandcombinationheaters
• waterheatersandhotwaterstoragetanks
• glandlessstandalonecirculatorsandglandlesscirculatorsintegratedinproducts
• waterpumps
• airconditionersandcomfortfans
• fansdrivenbymotorswithanelectricinputpowerbetween125Wand500kW
• lightingproductsinthedomesticandtertiarysectors
• electricmotors.
TheintentionisthattherecommendedminimumproductstandardsinthisguideshouldatleastmatchtheenergyefficiencystandardssetoutinCommissionRegulationsas they come into force.Forexample,althoughtheimplementingregulationsforhotwaterstoragetankswerepublishedinSeptember2013,thestandardsdonotcomeintoforceuntilSeptember2017.
If in any doubt as to whether a product is subject to minimum ecodesign standards, check the Commission document above.
TheEnergy Labelling Directive 2010/30/EUcomplementstheEcodesignDirectivebyprovidingaframeworkforlabellingofenergy-relatedproductsincludinglamps,luminaires,householdairconditionersandwashingmachines.TheEnergyLabelclassifiesproductsonanAtoGscale,‘pulling’themarkettowardsmoreefficientproductsbybetterinformingconsumers.TheEcodesignDirective,bycontrast,usesregulationto‘push’themarketawayfromtheworstperformingproducts.
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Section 1: Introduction
TheRenewable Energy Directive 2009/28/ECprovidesaframeworkforthepromotionofenergyfromrenewableresources.ItsetsamandatoryUKtargetof15%energygenerationfromrenewablesourcesby2020–the‘renewableenergyobligation’–asacontributiontomeetingtheEU’soveralltargetof20%.Ofrelevancetobuildingservicesisthatitincludescriteriafortrainingandcertificationofinstallersofrenewables.ThedirectivealsospecifiesinAnnexVIIthestandardsthatheatpumpsmustachievetoberecognisedasrenewabletechnologiesbythedirective.
TheEnergy Efficiency Directive2012/27/EUestablishesacommonframeworkofmeasuresforthepromotionofenergyefficiencywithintheEUinordertoensurethattheEUmeetsitstargetofa20%reductioninprimaryenergyconsumptionby2020.LegislationtoimplementthedirectiveintheUKwillbepublishedby5June2014.Includedwillberequirementsforpublicauthoritiestopurchaseonlyenergy-efficientproducts,servicesandbuildings;andrequirementsforheatmeterstobefittedinapartmentsandbuildingsconnectedtoacentralsourceofheatingordistrictheatingnetwork.Formoreinformationonthespecificrequirementsandtechnicalstandards,seetheDECCwebsite3.
TheEnergy Performance of Buildings Directive2010/31/EUisarecastoftheoriginal2002/91/ECdirective,whichin2002introducedrequirementsfor:
• theestablishmentofamethodologyforcalculatingtheintegratedenergyperformanceofbuildings
• minimumenergyperformancerequirementsfornewbuildings,and,wherefeasible,forlargerbuildingsundergoingmajorrenovation
• energyperformancecertificationofbuildings,and
• inspectionsofheatingandairconditioningsystems.
Therecastdirectiveincludesanewrequirementtoconsider,inthedesignofnewbuildings,thefeasibilityofusingrenewablesandother‘high-efficiencyalternativesystems’.Thereisnomandatoryformatforthisassessment,butitwillnowbenecessarytodeclare(throughanewfieldintheenergyperformancecalculationsoftware)thatithasbeencarriedout.
TheBuildingRegulations,whichalreadymettheoriginalrequirementsinmanyways(forexamplebysettingstandardsfornewbuildings),havebeenamendedinsomeplacestoreflectthenewrequirementsofthedirective.Forguidanceonthechangesaffectingnewbuildings,seeApprovedDocumentL2A.Forguidanceonthechangesaffectingmajorrenovations,seeApprovedDocumentL2B.Forguidanceonotherrequirementsrelatingtobuildingcertificationandinspectionofheatingandairconditioningsystems,seetheDCLGwebsite4.
1.4 StatusofguideTheBuildingRegulationscontainfunctionalrequirements,suchasrequirementsthatbuildingsmustbestructurallystable,constructedandfittedtoensurefireprotection,andenergyefficient.Thesefunctionalrequirementsareoftendraftedinbroadterms,andsoitmaynotalwaysbeimmediatelycleartoapersoncarryingoutworkhowtocomplywiththerelevantrequirements.Consequently,theDepartmentforCommunitiesandLocalGovernmentissuesdocuments,knownasapproveddocuments,whichprovidepracticalguidanceonwaysofcomplyingwithspecificaspectsoftheBuildingRegulationsinsomeofthemorecommonbuildingsituations.
Approveddocumentsarenotalwayscomprehensiveandmaycontainreferencestootherdocumentswhichwillprovidemoredetailedinformationandassistanceonpartsoftheguidance.Thisguideisoneofthosedocuments:itprovidesmoredetailedinformationontheguidancecontainedinApproved
3 https://www.gov.uk/decc4 https://www.gov.uk/dclg
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DocumentsL2AandL2Baboutcompliancewiththeenergyefficiencyrequirementswhichapplywheninstallingfixedbuildingservicesinnewandexistingbuildings.
Ifyoufollowtherelevantguidanceinanapproveddocument,andinanydocumentreferredtointheapproveddocument(suchasthisguide)whichprovidesadditionalinformationtohelpyoufollowthatguidance,thereisalegalpresumptionthatyouhavecompliedwiththeBuildingRegulations.However,ineachcaseitisforthebuildingcontrolbody(localauthorityorapprovedinspector)todecidewhetherworkcomplieswiththerequirementsoftheBuildingRegulations.ItisthereforesensiblethatyoucheckwiththebuildingcontrolbodybeforestartingworkwhattheyconsideritisnecessaryforyoutodotocomplywiththerequirementsoftheBuildingRegulations.
1.5 HowtousethisguideTheguideisdividedintothefollowingsections:
Section1:Introductionandsummaryofenergyefficiencystandards
Section2:Gas,oilandbiomass-firedboilers
Section3:Heatpumps
Section4:Gasandoil-firedwarmairheaters
Section5:Gasandoil-firedradiantheaters
Section6:Combinedheatandpowerandcommunityheating
Section7:Directelectricspaceheating
Section8:Domestichotwater
Section9:Comfortcooling
Section10:Airdistribution
Section11:Pipeworkandductworkinsulation
Section12:Lighting
Section13:Heatingandcoolingsystemcirculatorsandwaterpumps
Supplementaryinformationisshownagainstabluebackground.ThismaybefurtherinformationtohelpwithinterpretingtheminimumenergyefficiencyprovisionsneededtocomplywiththeBuildingRegulations.Oritmaybeguidanceonbestpracticethatgoesbeyondtherecommendedminimumstandards.
Keytermsareprintedinblueandaredefinedatappropriatepointsthroughouttheguide.
1.6 KeytermsforspaceheatinganddomestichotwatersystemsThefollowinggeneraldefinitionsareapplicabletothesectionsthatdealwithspaceheatingandhotwater.Furtherdefinitionsareincludedinlatersectionsasappropriate.
Heatgeneratormeansadeviceforconvertingfuelorelectricityintoheat–e.g.aboilerorradiantheater.
Heatgeneratorefficiencymeanstheusefulheatoutputdividedbytheenergyinputinthefuel(basedongrosscalorificvalue)orelectricitydeliveredtotheheatgenerator,asdeterminedbytheappropriatetestmethodsforthattypeofheatgenerator.
Heatgeneratorseasonalefficiency meanstheestimatedseasonalheatoutputfromtheheatgeneratordividedbytheenergyinput.Thiswilldependontheheatgeneratorefficiencyandtheoperatingmode
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oftheheatgeneratorovertheheatingseason.Forexample,inthecaseofboilersitisa‘weighted’averageoftheefficienciesoftheboilerat30%and100%oftheboileroutput.Forothertechnologiestheheatgeneratorseasonalefficiencymaybethesameastheheatgeneratorefficiency.
Minimumcontrolspackage meansapackageofcontrolsspecifictoeachtechnologythatrepresentstherecommendedminimumprovisionnecessarytomeettheBuildingRegulationsenergyefficiencyrequirements.
Additionalmeasures meansadditionalcontrolsorothermeasuresthatgobeyondtherecommendedminimumcontrolspackageandforwhichheatingefficiencycreditsareavailable.
Heatingefficiencycreditsareawardedfortheprovisionofadditionalmeasures,suchasadditionalcontrols,thatraisetheenergyefficiencyofthesystemandgobeyondrecommendedminimumstandards.Differentcreditsapplytothedifferentmeasuresthatareavailableforheatingandhotwatertechnologies.
Effectiveheatgeneratorseasonalefficiencyisobtainedbyaddingheatingefficiencycredits,whereapplicable,totheheatgeneratorseasonalefficiency:
Effectiveheatgeneratorseasonalefficiency=heatgeneratorseasonalefficiencyheatingefficiencycredits Equation 1
Whererelevant,thisguidesetsstandardsforeffectiveheatgeneratorseasonalefficiencysothataheatgeneratorwithaninherentlylowefficiencymaybeusedincombinationwithadditionalmeasures.
Spaceheatingsystemmeansthecompletesystemthatisinstalledtoprovideheatingtothespace.Itincludestheheatingplantandthedistributionsystembywhichheatingisdeliveredtozones.HeatlossesfromthedistributionsystemcanbeaddressedbyreferencetoguidancebyTIMSAonHVACinsulation5.
Domestichotwatersystemmeansalocalorcentralsystemforprovidinghotwaterforusebybuildingoccupants.
1.7 SummaryofrecommendedminimumenergyefficiencystandardsUnlessspecifiedotherwiseinthisguide,itisrecommendedthat,whereapplicable,buildingservicesareprovidedwithcontrolsthatasaminimumcorrespondtoBandCinBSEN15232:2012Energy performance of buildings. Impact of building automation, controls and building management.
5 TIMSAHVAC guidance for achieving compliance with Part L of the Building Regulationsatwww.timsa.org.uk
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6 EmergingEuropeanregulationsimplementingtheEcodesignDirectivesetminimumstandardsfortheefficiencyofenergy-usingproductsthatcanbeplacedonthemarket.Productsshouldalsocomplywiththesestandardsastheycomeintoeffect.Currentregulationsarelistedathttp://ec.europa.eu/energy/efficiency/ecodesign/doc/overview_legislation_eco-design.pdf.
7 Efficiencyisheatoutputdividedbycalorificvalueoffuel.Thenetcalorificvalueofafuelexcludesthelatentheatofwatervapourintheexhaust,andsoislowerthanthegrosscalorificvalue.EfficiencytestresultsandEuropeanstandardsnormallyusenetcalorificvalues.
8 Seasonalcoefficientofperformance(SCOP)isthecurrentEcodesignDirectivemeasureforspaceheatingair-to-airheatpumpswithanoutputofupto12kW.Eventually,themeasureusedwillbetheseasonalprimaryenergyefficiencyratio(SPEER),withtestingandratingtoBSEN14825:2013Air conditioners, liquid chilling packages and heat pumps with electrically driven compressors for space heating and cooling. Testing and rating at part load conditions and calculation of seasonal performance.EnergylabellingwiththeSPEERratingwillbemandatoryfrom2015.
9 RatingconditionsarestandardisedconditionsprovidedforthedeterminationofdatapresentedinBSEN14511:2013Air conditioners, liquid chilling packages and heat pumps with electrically driven compressors for space heating and cooling.
Table 1 Recommended minimum energy efficiency standards for building services6
Gas, oil and biomass-fired boilers:new buildings Seasonal efficiency (gross7)
Naturalgas Single-boilersystem2MWoutput 91%
Single-boilersystem2MWoutput 86%
Multiple-boilersystem 82%foranyindividualboiler86%foroverallmulti-boilersystem
LPG Single-boilersystem2MWoutput 93%
Single-boilersystem2MWoutput 87%
Multiple-boilersystem 82%foranyindividualboiler87%foroverallmulti-boilersystem
Oil Single-boilersystem 84%
Multiple-boilersystem 82%foranyindividualboiler84%foroverallmulti-boilersystem
Biomass–independent,automatic,pellet/woodchip 75%
Gas, oil and biomass-fired boilers:existing buildings
Seasonal efficiency (gross)
Actual Effective
Naturalgas 82% 84%
LPG 83% 85%
Oil 84% 86%
Biomass–independent,automatic,pellet/woodchip 75%
Heat pump units Coefficient of performance (COP)
Air-to-air Spaceheating12kW SeasonalCOP‘D’ratingformediantemperaturerangeinBSEN148258
Allothersexceptabsorptionandgas-engine
Spaceheating 2.5(250%)atratingconditionsinBSEN145119
Domestichotwater 2.0(200%)atratingconditionsinBSEN14511
Absorption 0.5(50%)whenoperatingattheratingconditions
Gas-engine 1.0(100%)whenoperatingattheratingconditions
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Section 1: Introduction
Table 1 Recommended minimum energy efficiency standards for building services (continued)
Gas and oil-fired warm air systems Thermal efficiency (net)
Gas-firedforcedconvection(naturalgas) 91%
Gas-firedforcedconvection(LPG) 91%
Directgas-firedforcedconvection 100%
Oil-firedforcedconvection 91%
Radiant heaters
Efficiency (net)
Thermal Radiant
Luminousradiantheater(unflued) 86% 55%
Non-luminousradiantheater(unflued) 86% 55%
Non-luminousradiantheater(flued) 86% 55%
Multi-burnerradiantheater 91% N/A
Combined heat and power (CHP) CHPQAquality index Power efficiency
Alltypes 105 20%
Electric (primary) heating Seasonal efficiency
Boilerandwarmair N/A
Domestic hot water systems
Heat generator seasonal efficiency (gross)
Thermal efficiencyBoiler seasonal efficiency
Direct-fired:newbuildings
Naturalgas30kWoutput 90%
Naturalgas30kWoutput 73%
LPG30kWoutput 92%
LPG30kWoutput 74%
Oil 76%
Direct-fired:existingbuildings
Naturalgas 73%
LPG 74%
Oil 75%
Indirect-fired(dedicatedhotwaterboiler)*:newandexistingbuildings
Naturalgas 80%
LPG 81%
Oil 82%
*SeeTable26formethodofcalculatingefficiencyforprimaryreturntemperaturesor55°C.
Electrically-heated:newandexistingbuildings N/A
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Table 1 Recommended minimum energy efficiency standards for building services (continued)
Comfort cooling systems Energy efficiency ratio (EER)
Packagedairconditioners–single-ducttypes 2.6
Packagedairconditioners–othertypes 2.6
Splitandmulti-splitairconditioners12kW 2.6
Splitandmulti-splitairconditioners12kW SCOP‘D’ratingformediantemperaturerangeinBSEN14825
Variablerefrigerantflowsystems 2.6
Vapourcompressioncyclechillers,watercooled750kW 3.9
Vapourcompressioncyclechillers,watercooled750kW 4.7
Vapourcompressioncyclechillers,aircooled750kW 2.55
Vapourcompressioncyclechillers,aircooled750kW 2.65
Waterloopheatpump 3.2
Absorptioncyclechillers 0.7
Gas-engine-drivenvariablerefrigerantflow 1.0
Air distribution systems
Specific fan power (SFP)10 (W/(l.s))
Newbuildings Existing buildings
Centralbalancedmechanicalventilationsystemwithheatingandcooling 1.6 2.2
Centralbalancedmechanicalventilationsystemwithheatingonly 1.5 1.8
Allothercentralbalancedmechanicalventilationsystems 1.1 1.6
Zonalsupplysystemwherefanisremotefromzone,suchasceilingvoidorroof-mountedunits
1.1 1.4
Zonalextractsystemwherefanisremotefromzone 0.5 0.5
Zonalsupplyandextractventilationunits,suchasceilingvoidorroofunitsservingasingleroomorzonewithheatingandheatrecovery
1.9 1.9
Localbalancedsupplyandextractventilationsystem,suchaswall/roofunitsservingsingleareawithheatingandheatrecovery
1.6 1.6
Localsupplyorextractventilationunitssuchaswindow/wall/roofunitsservingsinglearea(e.g.toiletextract)
0.3 0.4
Otherlocalventilationsupplyorextractunits 0.5 0.5
Fan-assistedterminalVAVunit 1.1 1.1
Fancoilunits(ratingweightedaverage) 0.5 0.5
Kitchenextract,fanremotefromzonewithgreasefilter 1.0 1.0
10 Maximumpressuredropisnotspecified.
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Table 1 Recommended minimum energy efficiency standards for building services (continued)
Air distribution systems: new and existing buildings Dry heat recovery efficiency
Plateheatexchanger 50%
Heatpipes 60%
Thermalwheel 65%
Runaroundcoil 45%
Internal lighting: option 1 Effective lighting efficacy
Generallightinginoffice,storageandindustrialareas 60luminairelumenspercircuit-watt
Generallightinginothertypesofspace 60lamplumenspercircuit-watt
Displaylighting 22lamplumenspercircuit-watt
Internal lighting: option 2 Lighting Energy Numeric Indicator (LENI)
Lightingsystem lightingenergylimit(kWh/m2/year)specifiedinTable44
Heating system circulators and water pumps Energy Efficiency Index
GlandlessstandalonecirculatorsGlandless,standaloneandintegratedcirculators
0.27until31July20150.23from1August2015
Waterpumps SeeSection13
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Section2:Gas,oilandbiomass-firedboilers
2.1 IntroductionThissectionprovidesguidanceonspecifyinggas,oilandbiomass-firedspaceheatingsystemsfornewandexistingbuildingstomeetrelevantenergyefficiencyrequirementsintheBuildingRegulations.Itcoversrelevantboilertypes,anddescribesmeasures,suchasadditionalcontrols,thatcanbeusedtogainheatingefficiencycreditstoimprovetheheatgeneratorseasonalefficiency.
2.2 ScopeofguidanceTheguidanceappliestowetcentralheatingsystemsusingcommercialboilersfiredby:
• naturalgas
• liquidpetroleumgas(LPG)
• oil,and
• biomass.
Theguidanceinthissectiondoesnotcover:
• steamboilers(astheseareusedprimarilyforprocessesratherthanprovisionofspaceheating),or
• electricboilers(forwhichseeSection7).
2.3 KeytermsTheterminologyusedtodescribeefficienciesforboilersystemsisdetailedbelow.Inthissectiontheheatgeneratorisaboiler.
Biomass means allmaterialofbiologicalorigin,excludingmaterialembeddedingeologicalformationsandtransformedtofossilfuel.
Boilerefficiency means theenergydeliveredbythewaterasitleavestheboiler(orboilersinmulti-boilerinstallations)tosupplytheheatemitters,dividedbytheenergy(basedongrosscalorificvalue)inthefueldeliveredtotheboiler,expressedasapercentage.Itisanexpressionoftheboiler’sperformanceandexcludesenergyusedbyboilerauxiliarycontrols,pumps,boilerroomventilationfans,mechanicalflueextractionfansandfandilutionsystems.TheboilerefficiencyismeasuredaccordingtothestandardsthatareusedtodemonstratecompliancewiththeBoilerEfficiencyDirective11.
Effectiveboilerseasonalefficiency istheboilerseasonalefficiency(ascalculatedbyEquation2belowforindividualboilers,orbyEquation3.1formultipleboilers),plusanyapplicableheatingefficiencycredits.
Economiser meansadevice,includingasecondaryheatexchangerfittedonorneartoaboiler,whichprovidesadditionalheattransfercapacity.Forthepurposesofthisguide,anyboilerwhichwillbesuppliedwithaneconomiser shouldhavetheeconomiserfittedwhentheboilerefficiencyistestedaccordingtothestandardsthatareusedtodemonstratecompliancewiththeBoilerEfficiencyDirective.Theeffectofthisontheboilerefficiencyat30%and100%oftheboileroutputmaybetakeninto
11 CouncilDirective92/42/EEC(theBoilerEfficiencyDirective)relatestotheefficiencyrequirementsfornewhotwaterboilersfiredwithliquidorgaseousfuels.TheassociatedUKlegislationistheBoiler(Efficiency)Regulations1993(SI1993/3083),amendedbytheBoiler(Efficiency)(Amendment)Regulations1994(SI1994/3083).
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Section 2: Gas, oil and biomass-fired boilers
accountinthevaluesusedforthecalculationoftheboilerseasonalefficiencyusingEquations2or3.1,orthethree-stepmethodandEquations3.2and3.3,asappropriate.
Condensingboiler means a boilerthatoffersahigherenergyefficiencybyrecoveringheatfromthefluegases.Thisisachievedbyincreasingtheheatexchangersurfacearea,whichrecoversextrasensibleheatwhenevertheboilerfires.Theboilerbecomesevenmoreefficientwhensystemwatertemperaturesarelowbecausethelargerheatexchangerareapromotescondensation,allowingmuchofthelatentheattoberecaptured.Standinglosses(whentheboilerisnotfiring)arelow,andpartloadperformanceisverygood.Inmultiple-boilersystems,condensingboilerscanbeusedastheleadboiler.
Standardboiler means, inthecontextofthisdocument,anon-condensingboiler.
Zonecontrol meansindependentcontrolofroomsorareaswithinbuildingsthatneedtobeheatedtodifferenttemperaturesatdifferenttimes.Whereseveralroomsorareasofabuildingbehaveinasimilarmanner,theycanbegroupedtogetherasa‘zone’andputonthesamecircuitandcontroller.
Sequencecontrol enablestwoormoreheatingboilerstobeswitchedonoroffinsequencewhentheheatingloadchanges.Thismaximisestheefficiencyoftheboilers,soreducingfuelconsumption,andreduceswearandtearontheboilers.
Directactingweathercompensation isatypeofcontrolthatenablesaheatgeneratortoworkatitsoptimumefficiency.Thecontrolallowstheboilertovaryitsoperatingflowtemperaturetosuittheexternaltemperatureconditionsandthetemperaturesinsidethebuilding.Weathercompensationreliesoncommunicationbetweenanexternalsensorandoneinsidetheboiler.Theboiler’swaterflowtemperatureisvariedaccordingly,sothatenergyisnotwastedbytheboilerturningonandoff.
Weathercompensationviaamixingvalve issimilartodirectactingweathercompensation,exceptthattheoutsidetemperatureisusedtocontrolthetemperatureofwatersuppliedtotheheatemittersbymixingtheboilerflowandreturnratherthanbyalteringtheboilertemperature.
Optimumstart isacontrolsystemoralgorithmwhichstartsplantoperationatthelatesttimepossibletoachievespecifiedconditionsatthestartoftheoccupancyperiod.
Optimiser isacontrolsystememployinganoptimumstartalgorithm.
Optimumstop isacontrolsystemoralgorithmwhichstopsplantoperationattheearliestpossibletimesuchthatinternalconditionswillnotdeterioratebeyondpresetlimitsbytheendoftheoccupancyperiod.
Two-stageburnercontrol isatypeofcontrolthatofferstwodistinctboilerfiringrates.
Multi-stageburnercontrol isatypeofcontrolthatoffersmorethantwodistinctfiringrates,butwithoutcontinuousadjustmentbetweenfiringrates.
Modulatingburnercontrol isatypeofcontrolthatprovidesa continuouslyvariablefiringrate,whichisalteredtomatchtheboilerloadoverthewholeturndownratio.
Decentralisation means thereplacementofcentralisedboilerplantanditsassociateddistributionpipeworkwithseveralsmaller,moreaccuratelysizedboilerplants,installedwithinoradjacenttothebuildingsorsystemstheyserve.Thiseliminateslongpiperunsbetweenbuildingsorthroughunheatedareas,soreducingheatlosses.
Buildingmanagementsystem(BMS) means abuilding-widenetworkwhichallowscommunicationwithandcontrolofitemsofHVACplant(andotherbuildingsystems)fromasinglecontrolcentre,whichmaybelocalorremote.Moreadvanced(‘full’)buildingmanagementsystemsofferawiderangeoffunctions,includingsequentialcontrol,zonecontrol,weathercompensation,frostprotectionandnightset-back,aswellasmonitoringandtargeting.
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2.4DeterminingboilerseasonalefficiencySingle-boiler systems and multiple-boiler systems with identical boilers
Forboilerstherelevantheatgeneratorseasonalefficiencyistheboilerseasonalefficiency.Theboilerseasonalefficiencyisa‘weighted’averageoftheefficienciesoftheboilerat15%,30%and100%oftheboileroutput(theefficiencyat15%beingtakentobethesameasthatat30%).Thisisusuallyquotedbytheboilermanufacturer.NotethattheefficienciesbasedonnetcalorificvalueshouldbeconvertedtoefficienciesbasedongrosscalorificvalueusingtheappropriateconversionfactorinSAP2012TableE4.
Theboilerefficiencies,measuredat100%loadandat30%load,areusedinEquation2tocalculatetheboilerseasonalefficiency.TheweightingfactorsinEquation2reflecttypicalseasonaloperatingconditionsforaboiler.
Boilerseasonalefficiency0.8130%0.19
100% Equation 212
where:
30%
isthegrossboilerefficiencymeasuredat30%load
100%
isthegrossboilerefficiencymeasuredat100%load.
Equation2appliesto:
• single-boilersystemswheretheboileroutputis400kWandtheboilerwilloperateonalowtemperaturesystem
• multiple-boilersystemswhereallindividualboilershaveidenticalefficienciesandwheretheoutputofeachboileris400kWoperatingonlowtemperaturesystems.
Forboilerswithanoutput400kW,themanufacturer’sdeclaredefficienciesshouldbeused.
Multiple-boiler systems with non-identical boilers replacing existing systems
Wheremorethanoneboilerisinstalledonthesameheatingsystemandtheefficienciesoftheboilersarenotallidentical,Equation3.1shouldbeusedtocalculatetheoverallboilerseasonalefficiency.Allboilersshouldbeincludedinthecalculation,evenwhensomeareidentical.
Theboilerseasonalefficiencyformultiple-boilersystemswithnon-identicalboilersis:
OBSE =
S(BSE
R)Equation 3.1
SR
where:
OBSE
isthegrossoverallboilerseasonalefficiency,beinganaverageweightedbyboileroutputoftheindividualseasonalboilerefficiencies
BSE
isthegrossboilerseasonalefficiencyofeachindividualboilercalculatedusingEquation2
RistheratedoutputinkWofeachindividualboiler(at80/60°C).
12 Thisequationassumesthattheefficiencyat15%loadisthesameasat30%load(andtheequationhasbeensimplifiedaccordingly).
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Section 2: Gas, oil and biomass-fired boilers
Multiple-boiler systems in new buildings
Inthecaseofmultipleboilersinnewbuildings,themoreaccuratethree-stepmethoddescribedbelowshouldbeusedtocalculatetheoverallseasonalboilerefficiency.Thesestepscanreadilybeprogrammedintoaspreadsheettoautomatethecalculation.
Step 1
Determinetheloadoneachboilerforeachofthethreesystempart-loadconditionsof15%,30%and100%.Forexample,ifthetotalsystemoutputismadeupofthreeequallysizedboilers,at15%ofsystemoutputtheleadboilerwillbeoperatingat45%ofitsratedoutput,withtheothertwoboilersswitchedoff.
Step 2
Determinetheefficiencyofeachboilerfortheaboveoperatingconditions.Intheaboveexample,theefficiencyoftheboileroperatingat45%canbedeterminedbylinearinterpolationbetweenitsefficienciesat30%and100%ofratedoutput.Whereitisnecessarytodeterminetheefficiencyofanindividualboilerat15%ofratedoutput,thisshouldbetakenasthesameastheefficiencyat30%ofratedoutput.(Notethattheefficiencyat15%ofratedoutputwillonlybeneededifasingleboilermeetsthefulldesignoutput.)
Step 3
Calculatetheoveralloperatingefficiencyateachofthesystempartloadconditionsusing:
pQ
p/S(q
b,p/
b,p) Equation 3.2
where:
pisthesystemefficiencyatpartloadconditionp,i.e.15%,30%and100%ofsystemratedoutput
Qpisthesystemheatoutputatpartloadconditionp
qb,p
istheindividualboilerheatoutputatsystempartloadconditionp
b,p
istheindividualboilerefficiencyatsystempartloadconditionp.
Calculatetheoverallboilerseasonalefficiencyastheweightedaverageoftheefficienciesatthethreeloadconditionsusing:
OBSE
0.3615%
0.4530%
0.19100%
Equation 3.3
Table2isaworksheetforfollowingthroughthesecalculations(usingmanufacturerdataforboilerefficiencyat100%and30%output).Table3showsacompletedexamplecalculationusingthisworksheet,forthecasewhereasystemwitharatedoutputof625kWisservedbythreeboilers,eachratedat250kW.Thefirsttwoboilersarecondensingboilers,whilethethirdisastandardboiler.Becausetheinstallationisoversized(750kWcomparedto625kW),atfullsystemoutputthefinalboilerisonlyoperatingat50%output(125/250).
Thenotesatthefootofthetableillustratehowthevariousvaluesarecalculated.
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Table 2 Worksheet for calculating the overall boiler seasonal efficiency of a multiple-boiler system using the alternative three-step method
Boiler % efficiency at boiler outputs of
Boiler % output at system outputs of
Boiler % efficiency at system outputs of
Boiler no Rating kW 100% 30% 15% 30% 100% 15% 30% 100%
1
2
3
Systemefficiencyatpartload
Weightingfactor 0.36 0.45 0.19
Overallheatgeneratorseasonalefficiency
Table 3 Example calculation of the overall boiler seasonal efficiency of a multiple-boiler system in a new building
Boiler % efficiency at boiler outputs of
Boiler % output at system outputs of
Boiler % efficiency at system outputs of
Boiler no Rating kW 30% 100% 15% 30% 100% 15% 30% 100%
1 250 90% 86% 38.0% 75.0% 100.0% 89.6%[1] 87.4% 86.0%
2 250 90% 86% notfiring notfiring 100.0% notfiring notfiring 86.0%
3 250 85% 82% notfiring notfiring 50.0% notfiring notfiring 84.1%
Systemefficiencyatpartload 89.6% 87.4% 85.6%[2]
Weightingfactor 0.36 0.45 0.19
Overallheatgeneratorseasonalefficiency 87.9%[3]
Notes [1] Calculatedbylinearinterpolation
b,p
30%–(
30%–
100%)
(qb,p
–30%)
(100%–30%)
1,15%
30%
–(30%
–100%
)(38%–30%)
(100%–30%)
[2] Calculatedbydividingthethermaloutputofthesystem(625kW)bytherateoffuelconsumption,whichisgivenbythesumoftheboileroutputsdividedbytheirindividualoperatingefficiency,i.e.
100%
625
250100%
250100%
25050% =85.6%
86.0% 86.0% 84.1%
[3] Calculatedastheweightedaverage,i.e.
89.6%0.3687.4%0.4585.6%0.1987.9%
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2.5 BoilersinnewbuildingsBackground
Newbuildingsshouldbeprovidedwithhighefficiencycondensingornon-condensingboilersthatmeettherecommendedminimumstandardsforheatgeneratorseasonalefficiencyinthisguide.
Commercialheatingsystemsareinherentlymorecomplicatedthandomesticsystemswithawiderrangeoftemperaturesandheatemitters.Theselectionofcondensingornon-condensingboilerswillbedeterminedbyapplicationandphysicalconstraints.
Note:Waterqualitycanhaveamajorimpactonsystemefficiency.Itisimportantthatdesignerstakeappropriatemeasurestoensurethatthesystemwaterisofgoodquality.
Condensingboilerswillmeetprojectedefficienciesonlywhentheyoperatewithasystemreturntemperaturebetween30°Cand40°Cfor80%oftheannualoperatinghours.Withareturntemperatureof55°Candabove,condensingboilerswillnotproducecondensateandwillhavesimilarefficienciestonon-condensinghighefficiencyboilers.Somesystemsaresuitableforweathercompensation,whichallowsreturntemperaturestofallintothecondensingrangeforsomeperiodsoftheheatingseason,andtheymaybebestservedbyamixtureofcondensingandnon-condensingboilers.
TheefficiencyvaluethatshouldbeenteredintoaccreditedNCMtoolstocalculatethecarbondioxideemissionrateistheeffectiveheatgeneratorseasonalefficiency.Forboilersinnewbuildings,noheatingefficiencycreditscanbegainedandtheeffectiveheatgeneratorseasonalefficiencyisthereforethesameastheheatgeneratorseasonalefficiency.
Recommended minimum standards
TomeetrelevantenergyefficiencyrequirementsintheBuildingRegulationswheninstallingboilerplantinnewbuildings:
a. whereasingleboilerisusedtomeettheheatdemand,itsboilerseasonalefficiency(grosscalorificvalue)calculatedusingEquation2shouldbenotlessthanthevalueinTable4
b. formultiple-boilersystems,theboilerseasonalefficiencyofeachboilershouldbenotlessthan82%(grosscalorificvalue),ascalculatedusingEquation2;andtheoverallboilerseasonalefficiencyofthemultiple-boilersystem,asdefinedbythethree-stepmethodandcalculatedusingEquations3.2and3.3,shouldbenotlessthanthevalueinTable4
c. therelevantminimumcontrolspackageinTable5shouldbeadopted.
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Table 4 Recommended minimum heat generator seasonal efficiency for boiler systems in new buildings
Fuel type SystemBoiler seasonal efficiency(gross calorific value)
Naturalgas Single-boiler2MWoutput 91%
Single-boiler2MWoutput 86%
Multiple-boiler 82%foranyindividualboiler86%foroverallmulti-boilersystem
LPG Single-boiler2MWoutput 93%
Single-boiler2MWoutput 87%
Multiple-boiler 82%foranyindividualboiler87%foroverallmulti-boilersystem
Oil Single-boiler 84%
Multiple-boiler 82%foranyindividualboiler84%foroverallmulti-boilersystem
Table 5 Recommended minimum controls package for new boilers and multiple-boiler systems
Boiler plant output Package Minimum controls
100kW A a. Timingandtemperaturedemandcontrol,whichshouldbezonespecificwherethebuildingfloorareaisgreaterthan150m2.
b. Weathercompensationexceptwhereaconstanttemperaturesupplyisrequired.
100kWto500kW B a. ControlspackageAabove.b. Optimumstart/stopcontrolwitheithernightset-backorfrost
protectionoutsideoccupiedperiods.c. Two-stagehigh/lowfiringfacilityinboiler,ormultipleboilerswith
sequencecontroltoprovideefficientpart-loadperformance.
Note:Theheatlossfromnon-firingboilermodulesshouldbelimitedbydesignorapplication.Forboilersthatdonothavelowstandinglosses,itmaybenecessarytoinstallisolationvalvesordampers.
500kWindividualboilers C a. ControlspackageAandcontrolspackageB.b. Forgas-firedboilersandmulti-stageoil-firedboilers,fullymodulating
burnercontrols.
2.6BoilersinexistingbuildingsBackground
Boilerefficiencieshaveimprovedmarkedlyoverrecentyears.AmodernboilermeetingtheminimumrequirementsoftheBoilerEfficiencyDirectivehasaboilerseasonalefficiencyofapproximately78.5%(basedongrosscalorificvalue).
Thisguidancerecognisesthatinmanycasesusingcondensingboilertechnologyinexistingbuildingswouldbeeithertechnicallyimpractical(duetoflueingconstraints)oreconomicallyunviable.Forthisreasonnon-condensingboilersmaybeusedprovidedthattheymeettherecommendedminimumefficiencystandardsgiveninthissection.
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Section 2: Gas, oil and biomass-fired boilers
Replacement boilers
TomeetrelevantenergyefficiencyrequirementsintheBuildingRegulationswheninstallingboilerplantinexistingbuildings:
a. theboilerseasonalefficiencyofeachboiler(inasingle-boilersystemoramultiple-boilersystemwithidenticalboilers)calculatedusingEquation2shouldbenotlessthanthevalueinTable6
b. formultiple-boilersystemsusingnon-identicalboilers,theoverallboilerseasonalefficiencycalculatedusingEquation3.1shouldbenotlessthanthevalueinTable6
c. thecontrolspackageinTable7shouldbeadopted–i.e.zonecontrol,demandcontrolandtimecontrol
d. theeffectiveboilerseasonalefficiencyshouldbenotlessthanthevalueinTable6.Tomeetthestandard,itmaybenecessarytoadoptadditionalmeasuresfromTable8inordertogainheatingefficiencycredits(seebelow).
Table 6 Recommended minimum heat generator seasonal efficiency for boiler systems in existing buildings
Fuel typeEffective boiler seasonal efficiency(gross calorific value)
Boiler seasonal efficiency(gross calorific value)
Naturalgas 84% 82%
LPG 85% 83%
Oil 86% 84%
Table 7 Recommended minimum controls package for replacement boilers in existing buildings
Minimum controls package Suitable controls
a. Zonecontrol Zonecontrolisrequiredonlyforbuildingswherethefloorareaisgreaterthan150m2.Asaminimum,on/offcontrol(e.g.throughanisolationvalveforunoccupiedzones)shouldbeprovided.
b. Demandcontrol Roomthermostatwhichcontrolsthroughadivertervalvewithconstantboilerflowwatertemperature.Thismethodofcontrolisnotsuitableforcondensingboilers.
c. Timecontrol Timeclockcontrols.
2.7 HeatingefficiencycreditsforreplacementboilersWheretheboilerseasonalefficiencyislessthantheminimumeffectiveboilerseasonalefficiencyforthattypeofboiler,additionalmeasures willneedtobeadoptedtoachievetheminimumeffectiveheatgeneratorseasonalefficiencyinTable6.
Table8indicatesthemeasuresthatmaybeadoptedandtherelevantheatingefficiencycreditsthatareapplicable.Itshouldbenotedthatthemaximumnumberofheatingefficiencycreditsthatcanbeclaimedis4percentagepoints.
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13 Themaximumthatcanbeclaimedis4points.
Table 8 Heating efficiency credits for measures applicable to boiler replacement in existing buildings
Measure
Heating efficiency credits(%points)13 Comments
A Boileroversize20% 2 Boileroversizeisdefinedastheamountbywhichthemaximumboilerheatoutputexceedsthesystemheatoutputatdesignconditions,expressedasapercentageofthatsystemheatoutput.Formultiple-boilersystemsthemaximumboilerheatoutputisthesumofthemaximumoutputsofalltheboilersinthesystem.
B Multipleboilers 1 Wheremorethanoneboilerisusedtomeettheheatload.
C Sequentialcontrolofmultiple-boilersystems
1 Appliesonlytomultiple-boiler/modulearrangements.Itisrecommendedthatthemostefficientboilershouldactastheleadinamultiple-boilersystem.
D Monitoringandtargeting 1 Meansofidentifyingchangesinoperationoronsetoffaults.Thecreditcanonlybeclaimedifmeteringisincludedandaschemefordatacollectionisprovidedandavailableforinspection.
E i.Thermostaticradiatorvalves(TRVs)alone.Wouldalsoapplytofannedconvectorsystems
1 TRVsenablethebuildingtemperaturetobecontrolledandthereforereducewasteofenergy.
ii.Weather(inside/outsidetemperature)compensationsystemusingamixingvalve
1.5 Providesmoreaccuratepredictionofloadandhencecontrol.
iii.AdditionofTRVortemperaturezonecontroltoiiabovetoensurefullbuildingtemperaturecontrol
1 ThiscreditisadditionaltoEiiabove.
F i.A‘room’thermostatorsensorthatcontrolsboilerwatertemperatureinrelationtoheatload
0.5
ii.Weather(inside/outsidetemperature)compensationsystemthatisdirectacting
2 Providesmoreaccuratepredictionofloadandhencecontrol.
iii.AdditionofTRVortemperaturezonecontroltoioriiabovetoensurefullbuildingtemperaturecontrol
1 ThiscreditisadditionaltoFiorFiiabove.NoteFiandFiiarenotusedtogether.
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Table 8 Heating efficiency credits for measures applicable to boiler replacement in existing buildings (continued)
Measure
Heating efficiency credits(%points)13 Comments
G i.Optimumstart 1.5 Acontrolsystemwhichstartsplantoperationatthelatesttimepossibletoachievespecifiedconditionsatthestartoftheoccupancyperiod.
ii.Optimumstop 0.5 Acontrolsystemwhichstopsplantoperationattheearliestpossibletimesuchthatinternalconditionswillnotdeterioratebeyondpresetlimitsbytheendoftheoccupancyperiod.
iii.Optimumstart/stop 2 Acontrolsystemwhichstartsplantoperationatthelatesttimepossibletoachievespecifiedconditionsatthestartoftheoccupancyperiodandstopsplantoperationattheearliestpossibletimesuchthatinternalconditionswillnotdeterioratebeyondpresetlimitsbytheendoftheoccupancyperiod.Notethatifoptimumstart/stopsystemsareinstalled,creditsGiandGiicannotalsobeclaimed.
H Fullzonedtimecontrol 1 Allowingeachzonetooperateindependentlyintermsofstart/stoptime.Onlyapplicablewhereoperationalconditionschangeindifferentzones.Doesnotincludelocaltemperaturecontrol.
I Fullbuildingmanagementsystem(BMS)
4 AfullBMSlinkedtotheheatingplantwillprovide:sequentialcontrolofmultipleboilers,fullzonedtimecontrolandweathercompensationwhereapplicable;frostprotectionornightset-back;optimisationandmonitoringandtargeting.NotethatifafullBMSisinstalled,nofurtherheatingefficiencycreditscanbeclaimed.
J Decentralisedheatingsystem 1 Eliminationoflongpiperunsbetweenbuildingsorthroughunheatedareasinbuildingsinordertoreduceexcessiveheatlosses.
Example: Usingheatingefficiencycredits toachievethe minimumeffectiveheatgeneratorseasonalefficiencyforaboilersysteminanexistingbuilding
Anexistingboileristobereplacedwithagasboilerwithaboilerseasonalefficiencyof82%,theminimumallowedbyTable6.
Theboiler’seffectiveboilerseasonalefficiencyneedstobeatleast84%accordingtoTable6,whichmeansthat2percentagepointsofheatingefficiencycreditsareneeded.
Thefollowingapproachwouldachievethis:
a. restrictboileroversizingto15%(afteradetailedassessmentofload)
b. fitaroomthermostattocontrolboilerwatertemperatureinrelationtoheatload
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c. usetwoequallysizedboilerstomeettheheatloadinplaceoftheexistingsingleboiler
d. fitTRVstocontrolthetemperatureinareasotherthanwheretheroomthermostatisfitted.
Table9belowshowshowcreditswouldbeawardedinthisexample.
Table 9 Example to illustrate allocation of heating efficiency credits for a replacement boiler in an existing building
Plant descriptionHeating efficiency credits(%points)
Boileroversizingislessthan20% 2
Systemcontrolledbyroomthermostatwhichcontrolsboilerwatertemperature 0.5
SystemusesTRVstoensurefullbuildingtemperaturecontrol 1
Multipleboilers 1
Total credits 4.5
Effectiveboilerseasonalefficiency
=boilerseasonalefficiencymaximumof4heatingefficiencycredits
=82486%
Inthisexampletheminimumeffectiveboilerseasonalefficiencyof84%isexceededby2percentagepoints.
2.8BiomassboilersBackground
ThemethodinSection2.4forcalculatingtheseasonalefficiencyofsingleandmultipleboilersfiredbygas,LPGandoilisnotappropriateforbiomassboilers.
Forbiomassboilers,requirementsandtestmethodsarecoveredbyBSEN12809:2001+A1:2004Residential independent boilers fired by solid fuel. Nominal heat output up to 50 kW. Requirements and test methods.
Recommended minimum standards
TomeetrelevantenergyefficiencyrequirementsintheBuildingRegulations:
a. theefficiencyofbiomassboilersattheirnominalloadshouldbeatleast:
i. 65%forindependentgravity-fedboilers20.5kW
ii. 75%forindependentautomaticpellet/woodchipboilers
b. controlsasforgas,LPGandoilboilersinTable5shouldbeprovided,wheretechnicallyfeasible.
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Section 3: Heat pumps
Section3:Heatpumps
3.1 IntroductionThissectiongivesguidanceonspecifyingheatpumpstoprovidespaceheatinganddomestichotwaterinnewandexistingbuildingstomeetrelevantenergyefficiencyrequirementsintheBuildingRegulations.
Theheatpumpscoveredinthissectiontakeheatenergyfromalowtemperaturesourceandupgradeittoahighertemperatureatwhichitcanbeusefullyemployedforheating.
Theguidancecoversmeasures,suchasadditionalcontrols,thatcanbeusedtogainheatingefficiencycreditstoimprovethecoefficientofperformanceofheatpumps.
Forguidanceonreversecycleheatpumpsthatalsoprovidecooling,seeSection9ofthisguide.
3.2 ScopeofguidanceTheguidanceinthissectionappliestothecommercialheatpumpsystemsidentifiedinTable10,whichcategorisesthedifferenttypesofheatpumpaccordingto:• thesourceoftheheat• themediumbywhichitisdelivered,and• thetechnology.
Table 10 Heat pump types and associated test standards
Heat pump type Technology Sub-technology Test standard
Electrically-driven warm air
Ground-to-air
Singlepackagevariablerefrigerantflowwarmairsystems ISO13256-114
Energytransfersystems(matchingheating/coolingdemandsinbuildings)
Water-to-air
Singlepackagevariablerefrigerantflowwarmairsystems BSEN14511-315
Energytransfersystems(matchingheating/coolingdemandsinbuildings)
Air-to-air Singlepackage BSEN14511-3
Splitsystem
Multi-splitsystem
Variablerefrigerantflowsystems
Electrically-driven warm water
Ground-to-water
Singlepackagevariablerefrigerantflowwarmairsystems ISO13256-216
Splitpackage
Water-to-water
Singlepackagevariablerefrigerantflowwarmairsystems BSEN14511-3
Splitpackage
Air-to-water
Singlepackage BSEN14511-3
Splitpackagevariablerefrigerantflowwarmairsystems
Gas-engine-driven
Availableasvariablerefrigerantflowwarmairsystems GenerallytoBSEN14511-3
14 ISO13256-1Water-source heat pumps. Testing and rating for performance. Part 1: Water-to-air and brine-to-air heat pumps.15 BSEN14511-3:2013Air conditioners, liquid chilling packages and heat pumps with electrically driven compressors for space heating and cooling. Test methods.16 ISO13256-2Water-source heat pumps. Testing and rating for performance. Part 2: Water-to-water and brine-to-water heat pumps.
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3.3 KeytermsCoefficientofperformance(COP)isameasureoftheefficiencyofaheatpumpatspecifiedsourceandsinktemperatures,butmaynotaccuratelyrepresentinstalledperformance:
HeatingCOPheatoutput/powerinput Equation 4
%COP(COP100)istheheatgeneratorefficiency.
Effective%COPisthe%COPwithheatingefficiencycredits.
TheCOPofaheatpumpshouldbedeterminedinaccordancewiththeappropriateteststandardidentifiedinTable10.Theinputpoweritemstobeincludedinthecalculationaredefinedinthestandard.
Seasonalcoefficientofperformance(SCOP) istheoverallcoefficientofperformanceoftheunitforthedesignatedheatingseason.Itmakesgeneralassumptionsabouttheamountofauxiliaryheatingneededtotopupthespaceandwaterheatingavailablefromtheheatpump.
SCOPismeasuredinaccordancewiththeproceduresinBSEN14825:2013Air conditioners, liquid chilling packages and heat pumps with electrically driven compressors for space heating and cooling. Testing and rating at part load conditions and calculation of seasonal performance.
TheNationalCalculationMethodologyforcalculatingcarbondioxideemissionratesfrombuildingsusesSCOP.
Seasonalperformancefactor(SPF)isanothermeasureoftheoperatingperformanceofanelectricheatpumpovertheseason.Itistheratiooftheheatdeliveredtothetotalelectricalenergysuppliedovertheseason,butthereareuptosevendifferentwaystodrawthesystemboundaries.Forexample,SPFH2
excludesauxiliaryresistanceheatingwhileSPF
H4includesit–makingalargedifference.
SAP2012calculations(fordwellings)useSPF–eithermeasuredvaluesforproductslistedintheProductCharacteristicsDatabase,orthedefaultvaluesinTable4aforproductsnotlistedthere.
TheMicrogenerationCertificationSchemeinstallationstandard,MIS3005,usesSPFtocalculatesystemperformance(althoughtheheatpumpproductstandard,MCS007,currentlyspecifiesaminimumCOP).
Seasonalprimaryenergyefficiencyratio(SPEER)isanemergingratingfigurereflectingtheuseofprimaryenergyforalltypesofheatpump,fossilfuelboilerandgas-drivencogenerationtechnologies,aswellashybridsystemswheresolarheatingoraheatpumpisbackedupwithelectricheatingorafossilfuelboiler.
EnergylabellingwiththeSPEERwillbemandatoryfrom2015undertheEnergyLabellingDirective.TestingandratingwillbeinaccordancewithBSEN14825,asforSCOP.
3.4 HeatpumpsinnewandexistingbuildingsAtthetimeofpreparationofthisguide,EuropeanCommissionRegulationNo206/2012setsstandardsonlyfortheSCOPofelectrically-drivenair-to-airheatpumpswithanoutput12kW.TherearecurrentlynoEuropeanteststandardsforpart-loadtestingofair-to-airheatpumpswithanoutput12kWorforothertypesofheatpump17,andsotheperformanceofthesemustbespecifiedusingCOPobtainedattheheatingsystemratingconditions.
17 Requirementsforheatpumpsdeliveringwaterwithanoutputupto400kWareexpectedtocomeintoforceinAugust2015.
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Section 3: Heat pumps
Thecurrentrecommendationsinthisguidearethatheatpumpsinnewandexistingbuildingsshould:
a. ifair-to-airwithanoutput12kW,haveatleastaSCOP‘D’ratingforthemediantemperaturerangeinBSEN14825
b. orelsehaveaCOPwhichisnotlessthanthevalueinTable11
c. featureasaminimumthecontrolspackageinTable12.
Table 11 Recommended minimum COP for heat pumps in new and existing buildings
Heat pump type Minimum COP at the rating conditions18
Alltypes(exceptair-to-airwithoutput12kW,absorptionandgas-engine)forspaceheating
2.5
Alltypes(exceptabsorptionandgas-engine)fordomestichotwaterheating
2.0
Absorption 0.5
Gas-engine 1.0
Fornon-residentialbuildings,theheatpumpsystemcanbesizedtomeeteitherthefullheatingandhotwaterdemandorpartofit.Economicallyviableinstallationsprovideatleast50%oftheheatingandhotwaterdemandforthebuilding.
Table 12 Recommended minimum controls package for heat pump systems in new and existing buildings
Heat source/sink Technology Minimum controls package
Alltypes Alltechnologies
A a. On/offzonecontrol.Iftheunitservesasinglezone,andforbuildingswithafloorareaof150m2orless,theminimumrequirementisachievedbydefault.
b. Timecontrol.
Air-to-air Singlepackage
Splitsystem
Multi-splitsystem
Variablerefrigerantflowsystem
B a. ControlspackageAabove.b. Heatpumpunitcontrolsfor:
i. controlofroomairtemperature(ifnotprovidedexternally)ii. controlofoutdoorfanoperationiii. defrostcontrolofexternalairsideheatexchangeriv. controlforsecondaryheating(iffitted).
c. Externalroomthermostat(ifnotprovidedintheheatpumpunit)toregulatethespacetemperatureandinterlockedwiththeheatpumpunitoperation.
18 RatingconditionsarestandardisedconditionsfordeterminingperformancespecifiedinBSEN14511:2013Air conditioners, liquid chilling packages and heat pumps with electrically driven compressors for space heating and cooling.
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Table 12 Recommended minimum controls package for heat pump systems in new and existing buildings (continued)
Heat source/sink Technology Minimum controls package
Water-to-airGround-to-air
Singlepackageenergytransfersystems(matchingheating/coolingdemandinbuildings)
D a. ControlspackageAabove.b. Heatpumpunitcontrolsfor:
i. controlofroomairtemperature(ifnotprovidedexternally)ii. controlofoutdoorfanoperationforcoolingtowerordrycooler
(energytransfersystems)iii. controlforsecondaryheating(iffitted)onair-to-airsystemsiv. controlofexternalwaterpumpoperation.
c. Externalroomthermostat(ifnotprovidedintheheatpumpunit)toregulatethespacetemperatureandinterlockedwiththeheatpumpunitoperation.
Air-to-waterWater-to-waterGround-to-water
Singlepackage
Splitpackage
E a. ControlspackageAabove.b. Heatpumpunitcontrolsfor:
i. controlofwaterpumpoperation(internalandexternalasappropriate)ii. controlofwatertemperatureforthedistributionsystemiii. controlofoutdoorfanoperationforair-to-waterunitsiv. defrostcontrolofexternalairsideheatexchangerforair-to-watersystems.
c. Externalroomthermostat(ifnotprovidedintheheatpumpunit)toregulatethespacetemperatureandinterlockedwiththeheatpumpunitoperation.
Gas-engine-drivenheatpumpsarecurrentlyavailableonlyasvariablerefrigerantflowwarmairsystems
Multi-split
Variablerefrigerantflow
F a. ControlspackageAabove.b. Heatpumpunitcontrolsfor:
i. controlofroomairtemperature(ifnotprovidedexternally)ii. controlofoutdoorfanoperationiii. defrostcontrolofexternalairsideheatexchangeriv. controlforsecondaryheating(iffitted).
c. Externalroomthermostat(ifnotprovidedintheheatpumpunit)toregulatethespacetemperatureandinterlockedwiththeheatpumpunitoperation.
3.5 HeatingefficiencycreditsforheatpumpsystemsinexistingbuildingsHeatingefficiencycreditscanbegainedforheatpumpsystemsinstalledinexistingbuildingsbyadoptingtheadditionalmeasuresinTable13.Thesecreditsareaddedtothe%COPtoproducetheeffective%COP.
Table 13 Heating efficiency credits for additional measures applicable to heat pump systems in existing buildings
Measure Heating efficiency credits (%points) Comments
20%oversizing 2 Theamountbywhichthemaximumheatpumpoutputexceedsthesystemheatoutputatdesignconditions,expressedasapercentageofthatsystemheatoutput.
Optimumstop 2 Acontrolsystemwhichstopsplantoperationattheearliestpossibletimesuchthatinternalconditionswillnotdeterioratebeyondpresetlimitsbytheendoftheoccupancyperiod.
Fullzonecontrol 2 Allowseachzonetooperateindependentlyintermsofstart/stoptime.Onlyappropriatewhereoperationalconditionschangeindifferentzones.
Monitoringandtargeting 2 Meansofidentifyingchangesinoperationoronsetoffaults.
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Section 3: Heat pumps
Example: Usingheatingefficiencycreditstoachievetherecommendedstandardforeffective%COPforaheatpumpinstallation
Aproposedsystemhasanair-to-water,electrically-drivenheatpumpsupplyingheattoanunderfloorheatingsystem.TheCOPoftheheatpumptestedtoBSEN14511is2.46,whichisbelowtheminimumstandardrecommendedbyTable11forspaceheating.
TheminimumcontrolspackagerecommendedbyTable12ispackageE,comprising:
a. zonecontrolandtimecontrol
b. heatpumpunitcontrolsfor:
i. controlofoutdoorfanoperationforcoolingtowerordrycooler(energytransfersystems)
ii. controlofexternalwaterpumpoperationandwatertemperatureforthedistributionsystem
c. roomthermostattoregulatethespacetemperatureandinterlockedwiththeheatpumpunitoperation.
Table14showstheheatingefficiencycreditsthatcanbegainedbyaddingoptimumstopcontrolandfullzonecontrol.
Effective%COP%COPheatingefficiencycredits2464250%
TheeffectiveCOPistherefore2.50,whichmeetstheminimumrequiredbyTable11.
Table 14 Example to illustrate the allocation of heating efficiency credits to a new heat pump system in an existing building
Measure Heating efficiency credits (%points)
MeasuresspecifiedincontrolspackageA 0(asthisistheminimumstandard)
MeasuresspecifiedincontrolspackageE 0(asthisistheminimumstandard)
Optimumstop 2
Fullzonecontrol 2
Total credits 4
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3.6 Supplementaryinformation
Heat source/sink Technology Comments
Air-to-air Singlepackage Unitsmaybeductedononeorotherofthesupplyandreturnairsidesorductedonbothsides.Ductingneedstobedesignedtotakeintoaccountthemaximumspecificfanpowerallowable(seeSection10ofthisguide)andtomaintaintheminimumallowablecoefficientofperformance.
Split
Multi-split
Variablerefrigerantflow
Gas-engine-driven
Asplitsystemwillcompriseasingleoutdoorunitandasingleindoorunitasapackage.Multi-splitandvariablerefrigerantflowsystemswillcompriseasingleoutdoorunitandtwoormoreindoorunitsasapackage.Severalpackagesmaybeusedtosatisfytherequirementsofthebuilding.
Inorderforefficienciestobemaintained,allconnectingpipeworkshouldbeinstalledinaccordancewithmanufacturers’recommendations(diameter,length,insulationandriserheight).Anyductingshouldbedesignedtotakeintoaccountthemaximumspecificfanpowerallowableandtomaintaintheminimumallowablecoefficientofperformance.
Water-to-air
Ground-to-air
Singlepackage
Energytransfer
Energytransfersystemsgenerallyconsistofmultiplewater-sourceheatpumpsconnectedinparalleltoacommonclosedwaterloop.Theyareinstalledtooffsetthesimultaneousheatingandcoolingdemandinabuildingduetothedifferentloadspresentontheaspectsofthebuilding.Watercirculationpumpsfortheclosedloopshouldbetakenintoconsiderationalongwiththefanpowerrequiredforthecoolingtowerordrycoolerorenergyforwaterpumpsforthegroundloopifthismethodisutilisedforheatinjectionandrejection.Anyductingshouldbedesignedtotakeintoaccountthemaximumspecificfanpowerallowableandtomaintaintheminimumallowablecoefficientofperformance.
Air-to-water
Water-to-ground
Water-to-water
Singlepackage
Splitpackage
Watercirculationpumpsforthedeliveryofheatedwatertothebuildingalongwiththeenergyofwaterpumpsusedfortheheatsource(waterorground)shouldbeconsideredinthecalculation.Anyductingshouldbedesignedtotakeintoaccountthemaximumspecificfanpowerallowableandtomaintaintheminimumallowablecoefficientofperformance.
AdditionalguidanceondesigncriteriaforheatingsystemswithintegratedheatpumpsisgiveninBSEN15450:2007 Heating systems in buildings. Design of heat pump heating systems.
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Section 4: Gas and oil-fired warm air heaters
Section4:Gasandoil-firedwarmairheaters
4.1 IntroductionThissectiongivesguidanceonspecifyinggasandoil-firedwarmairheatersforspaceheatinginnewandexistingbuildingstomeetrelevantenergyefficiencyrequirementsintheBuildingRegulations.Itincludesguidanceonmeasures,suchasadditionalcontrols,thatcanbeusedtogainheatingefficiencycreditstoimprovetheheatgeneratorseasonalefficiency.
4.2ScopeofguidanceTheguidanceinthissectioncoversthewarmairheaterslistedinTable15.Theguidancealsocoversindirectgasoroil-firedheatexchangers(asusedinlargeductedsystemsforofficeblocks,shoppingandleisurecomplexes,etc.)toprovideheatingandfreshorconditionedair.WarmaircentralheatingsystemsarenotwithinthescopeofthissectionbutarecoveredintherelevantheatgeneratorsectionandSection10Air distribution.
Table 15 Warm air heaters and test methods
Type of warm air heater Product standard
Type1 Gas-firedforcedconvectionwithoutafantoassisttransportationofcombustionairand/orcombustionproducts
BSEN621:200919
Type2 Gas-firedforcedconvectionincorporatingafantoassisttransportationofcombustionairand/orcombustionproducts
BSEN1020:200920
Type3 Directgas-firedforcedconvection BSEN525:200921
Type4 Oil-firedforcedconvection BSEN13842:200422
4.3 KeytermsHeatgeneratorseasonalefficiencyofairheaters,sincetheyoperateunderthesameconditionsatalltimes,isequivalenttotheirmeasuredsteadystatethermalefficiency(netcalorificvalue),whichcanbeobtainedfromtheheatermanufacturer’sdataandconvertedtoefficiency(grosscalorificvalue)usingtheconversionfactorsinSAP2012TableE4.
Forindirect-firedheaters,datavaluesforheatoutputandnetheatinputaremeasuredusingtheefficiencytestmethodsdescribedinBSEN1020,BSEN621orBSEN13842asappropriate.
Fordirect-firedheaters,theefficiencyshouldbecalculatedusingthemethoddescribedinBSEN525.19202122
19 BSEN621:2009Non-domestic gas-fired forced convection air heaters for space heating not exceeding a net heat input of 300 kW, without a fan to assist transportation of combustion air and/or combustion products.
20 BSEN1020:2009Non-domestic forced convection gas-fired air heaters for space heating not exceeding a net heat input of 300 kW, incorporating a fan to assist transportation of combustion air or combustion products.
21 BSEN525:2009Non-domestic direct gas-fired forced convection air heaters for space heating not exceeding a net heat input of 300 kW.22 BSEN13842:2004Oil-fired convection air heaters. Stationary and transportable for space heating.
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Thecalculationofthethermalefficiency(net)should:
• takeaccountoftheheaterandtheexhaustchimneywithinthebuildingenvelope
• excludefans.
Effectiveheatgeneratorseasonalefficiencyistheheatgeneratorseasonalefficiencywithaddedheatingefficiencycredits(seebelow).ItisthevalueenteredintoNCMtoolssuchasSBEMtocalculatethebuildingcarbondioxideemissionrate(BER).
4.4WarmairheatersinnewandexistingbuildingsWarmairsystemsinnewandexistingbuildingsshouldhave:
a. aneffectiveheatgeneratorseasonalefficiencywhichisnoworsethaninTable16
b. acontrolspackagefeaturing,asaminimum,timecontrol,spacetemperaturecontroland,whereappropriateforbuildingswithafloorareagreaterthan150m2,zonecontrol.
Table 16 Recommended minimum effective heat generator seasonal efficiency
Warm air heater type (seeTable15)Effective heat generator seasonal efficiency(net calorific value)
Types1,2naturalgas 91%
Types1,2LPG 91%
Type3* 100%
Type4 91%
*ForType3airheaters,100%ofthenetheatinputisdeliveredtothespace.SpecificventilationrequirementsasdefinedinBSEN525shouldbemet.
4.5 HeatingefficiencycreditsforwarmairheatersinnewandexistingbuildingsHeatingefficiencycreditscanbegainedbyadoptingtheadditionalmeasureslistedinTable17.
Table 17 Heating efficiency credits for additional measures applicable to warm air heaters
Measure
Heating efficiency credits(%points) Comments
Optimumstop 1 Acontrolsystemwhichstopsplantoperationattheearliestpossibletimesuchthatinternalconditionswillnotdeterioratebeyondpresetlimitsbytheendoftheoccupancyperiod.
Hi/Loburners 2 Two-stageburnerswhichenabletwodistinctfiringrates.
Modulatingburners 3 Burnercontrolswhichallowcontinuousadjustmentofthefiringrate.
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Section 4: Gas and oil-fired warm air heaters
Destratification fans and air-induction schemes
Itisrecognisedthatdestratificationfansandair-inductionschemesmayimprovetheefficiencyofawarmairsystemandsignificantlyreducethecarbonemissionsassociatedwiththeheatingsystem.ThebenefitsofthesemeasuresarealreadytakenintoaccountbytheNCMsonoheatingefficiencycreditscanbegainedbyusingthem.Notethatwarmairsystemswithairinductionschemesordestratificationfansshouldnotbeconfusedwithcentralheatingsystemsthathaveairdistribution.
Example: Usingheatingefficiencycreditstoexceedtheminimumeffectiveheatgeneratorseasonalefficiencyforawarmairheater
Aproposedbuildinghasagas-firedforced-convectionwarmairheaterwithoutafantoassisttransportationofcombustionairorcombustionproducts.WhentestedtoBSEN621:2009thethermalefficiency(netcalorificvalue)isfoundtobe91%,whichmeetstheminimumeffectiveheatgeneratingefficiencyrecommendedforthistypeofsysteminTable16.
Theminimumcontrolspackagespecifiedinparagraph4.4bcompriseszone,spacetemperatureandtimecontrols.Table18showshowcreditsareawardedbyaddingoptimumstopcontrol,modulatingburnersanddestratificationfans.
Table 18 Example to illustrate the allocation of heating efficiency credits to a warm airheater system
Measure Heating efficiency credits (%points)
Zone,spaceandtemperaturecontrols 0(asthisistheminimumstandard)
Modulatingburners 3
Optimumstop 1
Destratificationfans 0(asthebenefitsarealreadyrecognisedbytheNCM)
Total credits 4
Effectiveheatgeneratorseasonalefficiencynetthermalefficiencyheatingefficiencycredits
91495%
Theeffectiveheatgeneratorseasonalefficiencyistherefore95%,exceedingtheminimumstandardby4percentagepoints.ThevaluethatshouldbeenteredintotheaccreditedNCMtooltocalculatethecarbondioxideemissionrateis95%.
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Section5:Gasandoil-firedradiantheaters
5.1 IntroductionThissectiongivesguidanceonspecifyingradiantheatersforspaceheatinginnewandexistingbuildingstomeetrelevantenergyefficiencyrequirementsintheBuildingRegulations.Itincludesguidanceonmeasures,suchasadditionalcontrols,thatcanbeusedtogainheatingefficiencycreditstoimprovetheheatgeneratorseasonalefficiency.
5.2 ScopeofguidanceTheguidanceinthissectioncoversthetypesofradiantheaterlistedinTable19.
Table 19 Types of radiant heater and associated product standards
Radiant heater type Product standard
Luminousradiantheater BSEN419-1:200923
Non-luminousradiantheater BSEN416-1:200924
Multi-burnerradiantheater BSEN777series25
Oil-firedradiantheater N/A
5.3 KeytermsRadiantheaterseasonalefficiency(heatgeneratorseasonalefficiency)isequivalenttothermalefficiency(netcalorificvalue).232425Forfluedappliances,themanufactureroftheradiantheatershoulddeclareathermalefficiencymeasuredtotheteststandardsBSEN102026orBSEN1384227asapplicable.
Thecalculationofthethermalefficiency(netcalorificvalue)should:
a. takeaccountoftheradiantheaterandassociatedfluepipe/tailpipewithinthebuildingenvelope
b. excludefans.
23 BSEN419-1:2009Non-domestic gas-fired overhead luminous radiant heaters. Safety. 24 BSEN416-1:2009Single-burner gas-fired overhead radiant tube heaters. Safety. 25 BSEN777-1:2009Multi-burner gas-fired overhead radiant tube heater systems for non-domestic use. System D. Safety.
BSEN777-2:2009Multi-burner gas-fired overhead radiant tube heater systems for non-domestic use. System E. Safety. BSEN777-3:2009Multi-burner gas-fired overhead radiant tube heater systems for non-domestic use. System F. Safety. BSEN777-4:2009Multi-burner gas-fired overhead radiant tube heater systems for non-domestic use. System H. Safety.
26 BSEN1020:2009Non-domestic forced convection gas-fired air heaters for space heating not exceeding a net heat input of 300 kW, incorporating a fan to assist transportation of combustion air or combustion products.
27 BSEN13842:2004Oil-fired convection air heaters. Stationary and transportable for space heating.
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Section 5: Gas and oil-fired radiant heaters
5.4 RadiantheatersRadiantheatersinnewandexistingbuildingsshouldhave:
a. aneffectiveheatgeneratorseasonalefficiencynotworsethaninTable20
b. acontrolspackageconsistingof,asaminimum,timecontrolandspacetemperaturecontrolwithblackbulbsensors.
Table 20 Recommended minimum performance standards for radiant heaters
Appliance type
Effective heat generator seasonal efficiency
Thermal Radiant
Luminousradiantheater–unflued 86% 55%
Non-luminousradiantheater–unflued 86% 55%
Non-luminousradiantheater–flued 86% 55%
Multi-burnerradiantheater 91% N/A
5.5 HeatingefficiencycreditsforradiantheatersinexistingbuildingsHeatingefficiencycreditscanbegainedbyadoptingtheadditionalmeasureslistedinTable21.Theyareaddedtotheheatgeneratorseasonalefficiency(thethermalefficiency–netcalorificvalue)togivetheeffectiveheatgeneratorseasonalefficiency.
Table 21 Heating efficiency credits for additional measures applicable to radiant heaters
MeasureHeating efficiency credits(%points) Comments
Controls(additionaltotheminimumpackage)
Optimumstop 1 Acontrolsystemwhichstopsplantoperationattheearliestpossibletimesuchthatinternalconditionswillnotdeterioratebeyondpresetlimitsbytheendoftheoccupancyperiod.
Optimumstart 0.5 Acontrolsystemwhichstartsplantoperationatthelatestpossibletimesuchthatinternalconditionswillbeuptorequiredlimitsatthestartoftheoccupancyperiod.
Zonecontrol 1 Acontrolsysteminwhicheachzoneoperatesindependentlyintermsofstart/stoptime.Itisonlyappropriatewhereoperationalconditionschangeindifferentzones.
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Example: Usingheatingefficiencycreditstoachievetheminimumeffectiveheatgeneratorseasonalefficiencyforaradiantheatersystem
Aproposedbuildingwillhaveafluednon-luminousradiantheatersystemwithathermalefficiency(heatgeneratorseasonalefficiency)of84%.Ablackbulbsensorandanoptimiserwillbefitted.
Theheatingefficiencycreditsassociatedwiththesemeasuresareaddedtotheappliancethermalefficiencytoobtaintheeffectiveheatgeneratorseasonalefficiency.
Table22showshowcreditsareawardedforthisexample.
Table 22 Example to illustrate the allocation of heating efficiency credits to a radiantheater system
Measure Heating efficiency credits (%points)
Blackbulbsensor 0(asminimumrequirement)
Optimumstop 1
Zonecontrol 1
Total credits 2
Effectiveheatgeneratorseasonalefficiencythermalefficiencyheatingefficiencycredits
84286%
Inthisexample,theapplicationofadditionalmeasurestogainheatingefficiencycreditshasbroughttheradiantheater’seffectiveheatgeneratorseasonalefficiencyuptotheminimumrecommendedvalue.
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Section 6: Combined heat and power and community heating
Section6:Combinedheatandpowerandcommunityheating
6.1 IntroductionThissectiongivesguidanceonspecifyingcombinedheatandpower(CHP)systemsforspaceheating,hotwaterandchilledwater(viaabsorptionchillers)innewandexistingbuildingstomeetrelevantenergyefficiencyrequirementsintheBuildingRegulations.GuidanceonthedesignofcommunityheatingsystemscanbefoundinSection6oftheDomestic Building Services Compliance Guide.
CHPunitsarenormallyusedinconjunctionwithboilers.ThemajorityoftheannualheatdemandisusuallyprovidedbytheCHPplant,whiletheboilersareusedtomeetpeakdemandandinperiodswhentheCHPunitisnotoperating(forexampleatnightorwhenundergoingmaintenance).
CHPunitsmayonarelativelysmallscalesupplysinglebuildings,oronalargerscalesupplyanumberofbuildingsthroughacommunityheatingsystem.Themostcommonfuelisnaturalgas,whichcanbeusedinspark-ignitiongasengines,micro-turbines,orgasturbinesinopencycleorcombinedcycle.
6.2ScopeofguidanceTheguidanceinthissectioncoversCHPsystemswithatotalpowercapacitylessthan5MWeusedincommercialapplications.TheCHPunitsmayormaynotsupplycommunityheating.
Guidanceoncommunityheatingsystemswithmicro-CHP(havingatotalpowercapacitylessthan5kWe)andotherheatgeneratorsisavailableintheDomestic Building Services Compliance Guide.
6.3 KeytermsCombinedheatandpower(CHP) means thesimultaneousgenerationofheatandpowerinasingleprocess.Thepoweroutputisusuallyelectricity,butmayincludemechanicalpower.Heatoutputscanincludesteam,hotwaterorhotairforprocessheating,spaceheatingorabsorptioncooling.
CombinedHeatandPowerQualityAssurance(CHPQA) isascheme28underwhichregistrationandcertificationofCHPsystemsiscarriedoutaccordingtodefinedqualitycriteria.
CHPQAqualityindex isanindicatoroftheenergyefficiencyandenvironmentalperformanceofaCHPschemerelativetogenerationofthesameamountsofheatandpowerbyalternativemeans.
Powerefficiency isthetotalannualpoweroutputdividedbythetotalannualfuelinputofaCHPunit.
28 FurtherinformationabouttheCHPQAprogrammeisavailableatwww.chpqa.com.
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6.4CHPinnewandexistingbuildingsCHPplantinnewandexistingbuildingsshouldhave:
a. aminimumCHPQAqualityindex(QI)of105andpowerefficiencygreaterthan20%,bothunderannualoperation
b. acontrolsystemthat,asaminimum,ensuresthattheCHPunitoperatesastheleadheatgenerator
c. meteringtomeasurehoursrun,electricitygeneratedandfuelsuppliedtotheCHPunit.
TheCHPplantshouldbesizedtosupplynotlessthan45%oftheannualtotalheatingdemand(i.e.spaceheating,domestichotwaterheatingandprocessheating)unlessthereareoverridingpracticaloreconomicconstraints.
Calculating the carbon dioxide emissions from a CHP heating system
CHPmaybeusedasamainorsupplementaryheatsourceincommunityheatingsystems.TocalculatethecarbondioxideemissionrateforanewbuildingforthepurposesofshowingcompliancewiththeBuildingRegulations,thefollowingdatawillneedtobeenteredintoanaccreditedNCMtoolsuchasSBEM:
a. theproportion(P%)oftheannualheatdemand(HMWh)tobesuppliedbytheCHPplant(HP).ThisisneededastheCHPunitisnormallysizedbelowthepeakheatdemandofthebuildingandwillalsobeoutofserviceformaintenancepurposes
b. theoverallefficiencyratiooftheCHPplant(E)asdefinedbyEquation5andtakingaccountofpart-loadoperationandallheatrejectionpredictedbyanoperatingmodel:
E(annualusefulheatsuppliedannualelectricitygeneratednetofparasiticelectricityuse)/annualenergyofthefuelsupplied(ingrosscalorificvalueterms) Equation 5
c. theheattopowerratiooftheCHPplant(R),calculatedfortheannualoperationaccordingtoEquation6:
Rannualusefulheatsupplied/annualelectricitygeneratednetofparasiticelectricityuse Equation 6
Thecarbondioxideemittedinkg/yearfortheheatsuppliedbyagas-firedCHPplantisthen:
H P
H P 216
H P 519
E R E R
where216and519aretheassumedcarbondioxideemissionfactorsing/kWhformainsgasandgrid-displacedelectricityrespectively. Equation 7
ThecarbondioxideemittedforthebalanceofheatsuppliedbytheboilersisthencalculatedbytheNCMtoolasforaboileronlysystem.
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Section 6: Combined heat and power and community heating
6.5 Supplementaryinformation
Communityheatingsystemsmayincludeotherlowandzerocarbonsourcesofenergysuchasbiomassheating.Emissionfactorsshouldbedeterminedbasedontheparticulardetailsofthescheme,butshouldtakeaccountoftheannualaverageperformanceofthewholesystem–thatis,ofthedistributioncircuitsandalltheheatgeneratingplant,includinganyCHPandanywasteheatrecoveryorheatdumping.Thecalculationofthebuildingcarbondioxideemissionrateshouldbecarriedoutbyasuitablyqualifiedperson,whoshouldexplainhowtheemissionfactorswerederived.
Thedesignofthecommunityheatingconnectionandthebuilding’sheatingcontrolsystemshouldtakeaccountoftherequirementsofthecommunityheatingorganisationwithrespecttomaintaininglowreturntemperaturesatpart-loadandlimitingthemaximumflowratetobesuppliedbythecommunityheatingsystemtotheagreedlevel.Aheatmetershouldbeinstalledtomeasuretheheatenergysuppliedandtomonitorthemaximumheatdemand,themaximumcommunityheatingflowrateandthereturntemperaturesintothecommunityheatingnetwork.
Furtherguidancecanbefoundinthefollowingdocuments:
• CarbonTrustGPG234Community heating and CHP
• CIBSEAM12 Small-scale CHP for buildings
• HVCATR/30 Guide to good practice – Heat pumps.
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Section7:Directelectricspaceheating
7.1 IntroductionThissectiongivesguidanceonspecifyingdirectelectricheatersforspaceheatinginnewandexistingbuildings.Itaddressestherelevantelectricheatertypesandtheminimumprovisionofcontrols.
7.2 ScopeofguidanceTheguidancegiveninthissectioncoversthefollowingtypesofelectricheatingsystems,whichmaybeusedtoprovideprimaryorsecondaryspaceheating:
• electricboilers
• electricwarmairsystems
• electricpanelheaters
• electricstoragesystems,includingintegratedstorage/directsystems
• electricfanheatersandfanconvectorheaters
• electricradiantheaters,includingquartzandceramictypes.
Theguidancedoesnotcoverelectricheatpumpsorportableelectricheatingdevices.
7.3 ElectricspaceheatinginnewandexistingbuildingsItisassumedthatelectricheatingdevicesconvertelectricitytoheatwithinabuildingwithanefficiencyof100%.Aminimumheatgeneratorseasonalefficiencyisthereforenotspecified.
Electricspaceheatingsystemsinnewandexistingbuildingsshouldmeettheminimumstandardsfor:
a. controlsforelectricboilersinTable23
b. controlsforelectricheatingsystemsotherthanboilersinTable24.
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Section 7: Direct electric space heating
Table 23 Recommended minimum controls for electric boiler systems
Type of control Standard Comments
Boilertemperaturecontrol
a. Boilerfittedwithaflowtemperaturecontrolandcapableofmodulatingthepowerinputtotheprimarywaterdependingonspaceheatingconditions.
Zoning b. Forbuildingswithatotalusablefloorareagreaterthan150m2,atleasttwospaceheatingzoneswithindependenttimeandtemperaturecontrolsusingeither:i. multipleheatingzoneprogrammers,orii. asinglemulti-channelprogrammer.
Temperaturecontrolofspaceheating
c. Separatetemperaturecontrolofzoneswithinthebuildingusingeither:i. roomthermostatsorprogrammableroomthermostatsinall
zones,orii. aroomthermostatorprogrammableroomthermostatinthe
mainzoneandindividualradiatorcontrolssuchasthermostaticradiatorvalves(TRVs)onallradiatorsintheotherzones,or
iii. acombinationof(i)and(ii)above.
Timecontrolofspaceandwaterheating
d. Provideusing:i. afullprogrammerwithseparatetimecontrolforeachcircuit,
orii. separatetimersforeachcircuit,oriii. programmableroomthermostatsfortheheatingcircuits,with
separatetimecontrolforallthecircuits.
Note:Anacceptablealternativetotheabovecontrolsisanyboilermanagementcontrolsystemthatmeetsthespecifiedzoning,timingandtemperaturerequirements.
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Table 24 Recommended minimum controls for primary and secondary electric heating systems other than electric boilers
Type of electric heating system Type of control Standard Comments
Warmair Timeandtemperaturecontrol,eitherintegraltotheheaterorexternal
a. Atimeswitch/programmerandroomthermostat,or
b. aprogrammableroomthermostat.
Zonecontrol c. Forbuildingswithatotalusablefloorareagreaterthan150m2,atleasttwospaceheatingcircuitswithindependenttimingandtemperaturecontrolsusingeither:i. multipleheatingzoneprogrammers,orii. asinglemulti-channelprogrammer.
Radiantheaters Zoneoroccupancycontrol
a. Connectiontoapassiveinfra-reddetector. Electricradiantheaterscanprovidezoneheatingorbeusedforafullheatingscheme.Commonelectricradiantheatersincludethequartzandceramictypes.
Panel/skirtingheaters
Localtimeandtemperaturecontrol
a. Timecontrolprovidedby:i. aprogrammabletimeswitchintegratedinto
theappliance,orii. aseparatetimeswitch.
b. Individualtemperaturecontrolprovidedby:i. integralthermostats,orii. separateroomthermostats.
Panelheatersystemsprovideinstantaneousheat.
Storageheaters Chargecontrol a. Automaticcontrolofinputcharge(basedonanabilitytodetecttheinternaltemperatureandadjustthechargingoftheheateraccordingly).
Temperaturecontrol b. Manualcontrolsforadjustingtherateofheatreleasefromtheappliance,suchasadjustabledamperorsomeotherthermostatically-controlledmeans.
Fan/fanconvectorheaters
Localfancontrol a. Aswitchintegratedintotheappliance,orb. aseparateremoteswitch.
Individualtemperaturecontrol
c. Integralswitches,ord. separateremoteswitching.
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Section 8: Domestic hot water
Section8:Domestichotwater
8.1 IntroductionThissectiongivesguidanceonspecifyingdomestichotwater(DHW)systemsfornewandexistingbuildingstomeetrelevantenergyefficiencyrequirementsintheBuildingRegulations.Itincludesguidanceonmeasures,suchasadditionalcontrols,thatcanbeusedtogainheatingefficiencycreditstoimprovetheheatgeneratorseasonalefficiency.
Note:Waterqualitycanhaveamajorimpactonsystemefficiency.Itisimportantthatdesignerstakeappropriatemeasurestoensurethatthesystemwaterisofgoodquality.
AswellastheBuildingRegulations,otherregulationsapplytotheprovisionofdomestichotwater.Energy-savingmeasuresshouldnotcompromisethesafetyofpeopleortheabilityofthesystemtoachieveapprovedregimesforthecontroloflegionella.
DomestichotwatersystemsarereferredtoashotwaterservicesystemsinSBEM.
8.2ScopeofguidanceTheguidanceinthissectioncoverstheconventionaldirectandindirectgas-fired,oil-firedandelectrically-heateddomestichotwatersystemsshowninTable25.
Therecommendedminimumstandardssetoutinthissectionapplyonlytodedicatedwaterheaters.CentralheatingboilerswhichprovidespaceheatinganddomestichotwatershouldmeettheminimumstandardsinSection2;andheatpumpswhichprovidedomestichotwatershouldmeettheminimumstandardsinSection3.
Theguidanceinthissectionappliestoback-upgasandelectricsystemsusedwithsolarthermalhotwatersystems,butnottosolarthermalsystemsthemselves.Forsolarsystemswithacylindercapacityoflessthan440litresorcollectorsurfacearealessthan20m2,consulttheDCLGDomestic Building Services Compliance Guide,orforlargersystems,theCIBSESolar heating design and installation guide.
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Table 25 Types of hot water system
Direct-firedcirculator:naturalgasandLPG
Asysteminwhichthewaterissuppliedtothedraw-offpointsfromahotwatervesselinwhichwaterisheatedbycombustiongasesfromaprimaryenergysource.Theunithasnostoragevolumeaswaterisstoredinasupplementarystoragevessel.
Direct-firedstorage:naturalgas,LPGandoil
Asysteminwhichthewaterissuppliedtothedraw-offpointsfromanintegralhotwatervesselinwhichwaterisheatedbycombustiongasesfromaprimaryenergysource.
Direct-firedcontinuousflow:naturalgasandLPG
Asysteminwhichthewaterissuppliedtothedraw-offpointsfromadeviceinwhichcoldwaterisheatedbycombustiongasesfromaprimaryenergysourceasitflowsthroughthewaterheater.Thewaterheaterissituatedclosetothedraw-offpoints.Theunithasnostoragevolumeaswaterisinstantaneouslyheatedasitflowsthroughthedevice.
Indirect-firedcirculator:naturalgas,LPGandoil
Asysteminwhichthewaterissuppliedtothedraw-offpointsfromadeviceinwhichwaterisheatedbymeansofanelementthroughwhichtheheatingmediumiscirculatedinsuchamannerthatitdoesnotmixwiththehotwatersupply.Inpracticetheheatsourceislikelytobeaboilerdedicatedtothesupplyofdomestichotwater.
Instantaneouselectrically-heated
Asysteminwhichthewaterissuppliedtothedraw-offpointsfromadeviceinwhichcoldwaterisheatedbyanelectricelementorelementsasitflowsthroughthewaterheater.Thewaterheaterissituatedclosetothedraw-offpoints.Theunithasnostoragevolumeaswaterisinstantaneouslyheatedasitflowsthroughthedevice.
Point-of-useelectrically-heated
Asysteminwhichthewaterissuppliedtothedraw-offpointsfromadeviceinwhichwaterisheatedbyanelectricelementorelementsimmersedinthestoredwater.Thewaterheaterissituatedclosetothedraw-offpointsandshouldhaveastoragecapacitynogreaterthan100litres.
Localelectrically-heated
Asysteminwhichthewaterissuppliedtothedraw-offpointsfromadeviceinwhichwaterisheatedbyanelectricelementorelementsimmersedinthestoredwater.Thewaterheaterissituatedinthelocalityofthedraw-offpointsandshouldhaveastoragecapacityofbetween100and300litres.Bulkheatingofthewaterheatershouldbewithoff-peakelectricity.
Centralisedelectrically-heated
Asysteminwhichthewaterissuppliedtothedraw-offpointsfromadeviceinwhichwaterisheatedbyanelectricelementorelementsimmersedinthestoredwater.Thewaterheaterissituatedcentrallywithadistributionsystemtosupplywatertothedrawoff-pointsandshouldhaveacapacitygreaterthan300litres.Bulkheatingofthewaterheatershouldbewithoff-peakelectricity.
8.3 KeytermsTheheatgeneratorseasonalefficiencyisdefinedforeachsystemtypeinTable26.
TheeffectiveheatgeneratorseasonalefficiencyistheheatgeneratorseasonalefficiencyplusheatingefficiencycreditsgainedbyadoptingadditionalmeasuresfromTable31.
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Section 8: Domestic hot water
Table 26 Definition of heat generator seasonal efficiency for DHW systems
DHW system type Heat generator seasonal efficiency Comments on calculation[1]
Direct-firedcirculator:naturalgasandLPG
Equalsthethermalefficiencyoftheheater(grosscalorificvalue)whentestedtoBSEN15502-2-1:201229.[2]
Exclude:a. secondarypipeworkb. fansandpumpsc. divertervalves,solenoids,
actuatorsd. supplementarystorage
vessels.
Direct-firedstorage:naturalgas,LPGandoil
Equalsthethermalefficiencyoftheheater(grosscalorificvalue)whentestedusingtheproceduresinBSEN89:200030.[2]
Include thewaterheaterandinsulationoftheintegralstoragevesselonly.
Direct-firedcontinuousflow:naturalgasandLPG
Equalsthethermalefficiencyoftheheater(grosscalorificvalue)whentestedtoBSEN26:199831.
Exclude:a. secondarypipeworkb. fansandpumpsc. divertervalves,solenoids,
actuatorsd. supplementarystorage
vessels.
Indirect-firedcirculator:naturalgas,LPGandoil
CalculateusingEquations2,3.1,or3.2and3.3(asappropriate)inSection2.
UseEquation2(0.8130%
0.19100%
)tocalculateboilerseasonalefficiencyifprimaryreturntemperature55°C.
Useboilerfullloadefficiency(1.0100%
)at80/60°Cflow/returntemperaturesifprimaryreturntemperature55°C.
IfboilerseasonalefficiencyvaluesareobtainedasnetvaluesthefactorsinSAP2012TableE4shouldbeusedtoconverttogrossvalues.
Include theheatgeneratoronly.
Electrically-heated Theseareassumed100%thermallyefficientintermsofconversiontoheatwithinthebuilding.
Notes[1] Forhotwatersystemsinnewbuildings,standinglossesarecalculatedintheaccreditedNCMtool.[2] Whereefficiencydataisnotreadilyavailable,efficienciescanbecalculatedusingmanufacturers’recoveryratesand
thefollowingequations:
Grossthermalefficiencyheateroutput/grossinput Equation 8
Heateroutputrecoveryrateofheaterinlitres/secondspecificheatcapacityofwatertemperatureriseofwater Equation 9
29 BSEN15502-2-1:2012Specific standard for type C appliances and type B2, B3 and B5 appliances of a nominal heat input not exceeding 1000 kW.30 BSEN89:2000Gas fired water heaters for the production of domestic hot water. Direct-fired storage water heaters, Section 8.2, Maintenance consumption.31 BSEN26:1998Gas fired instantaneous water heaters for the production of domestic hot water, fitted with atmospheric burners.
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8.4DomestichotwatersystemsinnewandexistingbuildingsDomestichotwatersystemsinnewandexistingbuildingsshouldmeettherecommendedminimumstandardsfor:
a. heatlossesfromDHWstoragevesselsinTable27,ormaintenanceconsumptionvaluesinBSEN89:2000
b. heatgeneratorefficiency(grosscalorificvalue)inTable28
c. controlsinTables29and30.
Table 27 Recommended maximum heat losses from DHW storage vessels
Nominal volume(litres)
Heat loss(kWh/24h)
Nominal volume (litres)
Heat loss(kWh/24h)
200 2.1 900 4.5
300 2.6 1000 4.7
400 3.1 1100 4.8
500 3.5 1200 4.9
600 3.8 1300 5.0
700 4.1 1500 5.1
800 4.3 2000 5.2
Notes[1] ForguidanceonmaximumheatlossesfromDHWstoragevesselswithastoragevolumelessthan200litres,see
BSEN15450:200732.[2] Theheatlossfromelectrically-heatedcylinders(volumeVlitres)shouldnotexceed1.28(0.20.051V2/3)
ifpoint-of-useor1.28(0.051V2/3)iflocal.
32 BSEN15450:2007Heating systems in buildings. Design of heat pump heating systems.
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Section 8: Domestic hot water
Table 28 Recommended minimum thermal efficiencies for domestic hot water systems
DHW system type Fuel type Heat generator seasonal efficiency (gross)
Thermal efficiencyBoiler seasonal efficiency
Direct-fired:newbuildings
Naturalgas30kWoutput 90%
Naturalgas30kWoutput 73%
LPG30kWoutput 92%
LPG30kWoutput 74%
Oil 76%
Direct-fired:existingbuildings
Naturalgas 73%
LPG 74%
Oil 75%
Indirect-fired:newandexistingbuildings
Naturalgas 80%
LPG 81%
Oil 82%
Electrically-heated:newandexistingbuildings
100%assumed
Table 29 Recommended minimum controls package for gas and oil-fired domestic hotwater systems
DHW system type Controls package
Direct-firedcirculator:naturalgasandLPG
a. Automaticthermostatcontroltoshutofftheburner/primaryheatsupplywhenthedesiredtemperatureofthehotwaterhasbeenreached.
b. Highlimitthermostattoshutoffprimaryflowifsystemtemperaturetoohigh.c. Timecontrol.
Direct-firedstorage:naturalgas,LPGandoil
a. Automaticthermostatcontroltoshutofftheburner/primaryheatsupplywhenthedesiredtemperatureofthehotwaterhasbeenreached.
b. Highlimitthermostattoshutoffprimaryflowifsystemtemperaturetoohigh.c. Timecontrol.
Direct-firedcontinuousflow:naturalgasandLPG
a. Outlettemperatureofappliancecontrolledbyrateofflowthroughheatexchanger.b. Highlimitthermostattoshutoffprimaryflowifsystemtemperaturetoohigh.c. Flowsensorthatonlyallowselectricalinputshouldsufficientflowthroughtheunitbe
achieved.d. Timecontrol.
Indirect-fired:naturalgas,LPGandoil
a. Automaticthermostatcontroltoshutofftheburner/primaryheatsupplywhenthedesiredtemperatureofthehotwaterhasbeenreached.
b. Highlimitthermostattoshutoffprimaryflowifsystemtemperaturetoohigh.c. Timecontrol.
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Table 30 Recommended minimum controls package for electrically-heated domestic hotwater systems
Point-of-use Local Centralised Instantaneous
Automaticthermostatcontroltointerrupttheelectricalsupplywhenthedesiredstoragetemperaturehasbeenreached.
Yes Yes Yes x
Highlimitthermostat(thermalcut-out)tointerrupttheenergysupplyifthesystemtemperaturegetstoohigh.
Yes Yes Yes x
Manualresetintheeventofanover-temperaturetrip. Yes Yes Yes x
7-daytimeclock(orBMSinterface)toensurebulkheatingofwaterusingoff-peakelectricity.Facilitytoboostthetemperatureusingon-peakelectricity(ideallybymeansofanimmersionheaterfittedtoheatthetop30%ofthecylinder).
x Yes Yes x
Highlimitthermostat(thermalcut-out)tointerrupttheenergysupplyiftheoutlettemperaturegetstoohigh.(Note:Outlettemperatureiscontrolledbyrateofflowthroughtheunit,whichonbasicunitswouldbebytheoutlettaporfitting.)
x x x Yes
Flow/pressuresensorthatonlyallowselectricalinputshouldsufficientflowthroughtheunitbeachieved.
x x x Yes
8.5Supplementaryinformationonelectricwaterheaters
Point-of-use
• RelevantstandardisBSEN60335-2-21:2003+A2:200833.
Instantaneous
• RelevantstandardisBSEN60335-2-35:2002+A2:201134.
Local
• Forventedsystems,relevantstandardisBSEN60335-2-21:2003+A2:2008.
• Forunventedsystems,relevantstandardisBSEN12897:200635.
Centralised
• RelevantstandardisBS853-1:1990+A3:201136.
• Bulkheatingofthewatershouldutiliseoff-peakelectricitywherepossible.
• Whenusingoff-peakelectricitya‘boostheater’shouldbefittedtoallow‘on-peak’heating.Theboostheatershouldheatthetop30%ofthecylinderandberatedtoapproximately30%ofthemainoff-peakheaterbattery.ThekWloadwilldependontherecoverytimerequired.
33 BSEN60335-2-21:2003+A2:2008Specification for safety of household and similar electrical appliances. Particular requirements for storage water heaters.34 BSEN60335-2-35:2002+A2:2011Specification for safety of household and similar electrical appliances. Particular requirements for instantaneous water heaters.35 BSEN12897:2006 Water supply. Specification for indirectly heated unvented (closed) storage water heaters.36 BS853-1:1990+A3:2011Calorifiers and storage vessels for central heating and hot water supplies.
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• Theheaterbatteryshouldeitherbeofremovablecoreorrodelementconstruction.Removablecoreconstructionallowselementstobechangedwithoutremovingtheheaterfromthevesselordrainingthesystem.Forremovablecoreconstruction,themaximumelementwattsdensityshouldnotexceed3W/cm2forcoppertubesor2.5W/cm2forstainlesssteeltubes.Forrodelementconstruction,elementsshouldbeofnickelalloy825sheath,beU-bentandhaveamaximumwattsdensityof10W/cm2.Temperaturecontrolshouldbebymeansof‘on/off’controloftheheaterbatteryutilisingstagerampingforloadingsabove30kW.Thermostaticcontrolisanidealsolution.
• Thecontrolsensorshouldbemountedinthecylinderatanangleofapproximately45°totheheaterandataleveljustabovetheheatingbundle.Theover-temperaturesensor(highlimit)shouldbemountedinthetop30%ofthecylinderdirectlyabovetheheaterbundle.Amanualresetshouldberequiredintheeventofanover-temperaturetrip.
• Forloadingsgreaterthan6kW,temperaturesensorsshouldnotbefittedtotheheaterbundle.Thisistopreventthermostatandcontactorcyclingwhichwillleadtoprematurefailureoftheequipmentandpoortemperaturecontrol.
8.6HeatingefficiencycreditsfordomestichotwatersystemsinnewandexistingbuildingsHeatingefficiencycreditsareavailableforgasandoil-firedsystemsfortheadditionalmeasureslistedinTable31.Ifthesemeasuresareadopted,heatingefficiencycreditscanbeaddedtotheheatgeneratorseasonalefficiencytogivetheeffectiveheatgeneratorseasonalefficiency,whichisthevalueenteredintotheaccreditedNCMtoolinordertocalculatethecarbondioxideemissionrateforabuilding.
Effectiveheatgeneratorseasonalefficiencyheatgeneratorseasonalefficiencyheatingefficiencycredits
wheretheheatgeneratorseasonalefficiencyis:
• thethermalefficiencyfordirect-firedsystems
• theboilerseasonalefficiencyforindirect-firedsystems.
Table 31 Heating efficiency credits for additional measures applicable to domestic hot water systems
System type Measure Heating efficiency credits (%points)
All Decentralisation 2,butnotapplicabletosystemsinnewbuildings
Direct-fired Integralcombustioncircuitshut-offdevice 1
Fullyautomaticignitioncontrols 0.5
All Correctsizeofunitconfirmedusingmanufacturer’stechnicalhelplineandsizingsoftware
2
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Example: Usingheatingefficiencycredits toimprovetheheatgeneratorseasonalefficiencyforadirect-firedcirculatorsystem
Step 1: Calculatingthermalefficiency ofdirect-firedDHWsystem
• recoveryrateofheater0.3830litres/s
• grossinputrateofheater83.5kW
• specificheatcapacityofwater4.186kJ/(kg.K)
• temperatureriseofwaterinsideheater50°C.
UsingEquation9:
Heateroutputrecoveryrateofheaterinlitres/secondspecificheatcapacityofwatertemperatureriseofthewater
0.38304.1865080.16kW
UsingEquation8:
Thermalefficiency(gross)outputoftheheater/grossinput
• 80.16/83.50.96(96%)
Step 2: Addingheatingefficiencycredits foradditionalmeasures
Theheaterhasbeensizedtocloselymatchthesystemdemandbyusingthemanufacturer’ssizingguideandhasfullyautomaticcontrols.
Table32showshowcreditswouldbeassignedinthisexample.
Table 32 Example to illustrate allocation of heating efficiency credits for a DHW system
Measure Heating efficiency credits (%points)
Sizedaccordingtomanufacturer’sguidance 2
Fullyautomaticignitioncontrols 0.5
Total credits 2.5
Effectiveheatgeneratorseasonalefficiencythermalefficiency(gross)heatingefficiencycredits
962.598.5%
Inthisexample,thevalue98.5%wouldbeenteredintheNCMtool.
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Section 9: Comfort cooling
Section9:Comfortcooling
9.1 IntroductionThissectiongivesguidanceonspecifyingcomfortcoolingfornewandexistingbuildingstomeetrelevantenergyefficiencyrequirementsintheBuildingRegulations.ItincludesguidanceonusingSBEMtocalculatethecarbondioxideemissionsassociatedwithcomfortcoolinginnewbuildings.
9.2ScopeofguidanceTheguidancecoversthespecificationofrefrigerationplantefficiencyintermsoftheseasonalenergyefficiencyratio(SEER),whichisthevalueusedbySBEMtocalculatethecarbondioxideemissionrateforanewbuilding.SBEMallocatesstandardcorrectionfactors37totheperformanceofcoolingplanttoaccountfortheuseofthedifferentsystemsfordistributingcoolingtothespaces.Evaporativecoolinganddesiccantcoolingsystemsarenotwithinthescopeofthisguidance.
9.3 KeytermsCoolingplant meansthatpartofacoolingsystemthatproducesthesupplyofcoolingmedium.Itdoesnotincludemeansofdistributingthecoolingmediumorthedeliveryofthecoolingintotherelevantzone.Itmayconsist,forexample,ofasinglechilleroraseriesofchillers.
Coolingsystem means thecompletesystemthatisinstalledtoprovidethecomfortcoolingtothespace.Itincludesthecoolingplantandthesystembywhichthecoolingmediumeffectscoolingintherelevantzoneandtheassociatedcontrols.Thiswillinsomecasesbeacompletepackagedairconditioner.
Energyefficiencyratio(EER) forchillersisthecoolingenergydeliveredintothecoolingsystemdividedbytheenergyinputtothechiller,asdeterminedbyBSEN1451138.
Inthecaseofpackagedairconditioners,theEERistheenergyremovedfromairwithintheconditionedspacedividedbytheeffectiveenergyinputtotheunit,asdeterminedbyBSEN14511orotherappropriatestandardprocedure.ThetestconditionsfordeterminingEERarethosespecifiedinBSEN14511.
Partloadenergyefficiencyratio isthecoolingenergydeliveredintothecoolingsystemdividedbytheenergyinputtothecoolingplant.Partloadperformanceforindividualchillersisdeterminedassumingchilledwaterprovisionat7°Coutand12°Cin(at100%load),underthefollowingconditions:
Percentage part load 25% 50% 75% 100%
Air-cooledchillersambientairtemperature(°C)
20 25 30 35
Water-cooledchillersenteringcoolingwatertemperature(°C)
18 22 26 30
Seasonalenergyefficiencyratio(SEER)isthetotalamountofcoolingenergyprovideddividedbythetotalenergyinputtoasinglecoolingunit,summedovertheyear.
37 TheSBEMTechnicalManualisavailablefordownloadfromwww.ncm.bre.co.uk38 BSEN14511-2:2013Air conditioners, liquid chilling packages and heat pumps with electrically driven compressors for space heating and cooling. Test conditions.
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EuropeanSeasonalEnergyEfficiencyRatio(ESEER)istheSEERofacoolingunitasdeterminedundertheEuroventCertificationscheme.
Plantseasonalenergyefficiencyratio(PSEER)isthetotalamountofcoolingenergyprovideddividedbythetotalenergyinputtothecoolingplant(whichmaycomprisemorethanonecoolingunit),summedovertheyear.
9.4ComfortcoolinginnewandexistingbuildingsForcomfortcoolingsystemsinnewandexistingbuildings:
a. coolingunitsshouldcomplywithEuropeanCommissionRegulationNo327/2011forfansdrivenbymotorswithanelectricalinputpowerbetween125Wand500kW,andRegulationNo206/2012forsystemswithacoolingcapacityofupto12kW,bothimplementingDirective2009/125/ECwithregardstoecodesignrequirementsforenergy-relatedproducts
b. thefullloadenergyefficiencyratio(EER)ofeachcoolingunitofthecoolingplantshouldbenoworsethanrecommendedinTable33
c. controlsshouldcomplywithBSEN15232:201239BandCandbenoworsethanrecommendedinTable34.
Table 33 Recommended minimum energy efficiency ratio (EER) for comfort cooling
Type Cooling unit full load EER
Packagedairconditioners Single-ducttype 2.6
Othertypes 2.6
Splitandmulti-splitairconditioners12kW 2.6
Splitandmulti-splitairconditioners12kW SCOP‘D’ratingformediantemperaturerangeinBSEN14825:201340
Variablerefrigerantflowsystems 2.6
Vapourcompressioncyclechillers,water-cooled750kW 3.9
Vapourcompressioncyclechillers,water-cooled750kW 4.7
Vapourcompressioncyclechillers,air-cooled750kW 2.55
Vapourcompressioncyclechillers,air-cooled750kW 2.65
Waterloopheatpump 3.2
Absorptioncyclechillers 0.7
Gas-engine-drivenvariablerefrigerantflow 1.0
39 BSEN15232:2012Energy performance of buildings. Impact of building automation, controls and building management.40 BSEN14825:2013Air conditioners, liquid chilling packages and heat pumps with electrically driven compressors for space heating and cooling. Testing and rating at part load conditions
and calculation of seasonal performance.
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Table 34 Recommended minimum controls for comfort cooling in new and existing buildings
Controls
Cooling plant a. Multiplecoolingunitsshouldbeprovidedwithcontrolsthatensurethecombinedplantoperatesinitsmostefficientmodes.
Cooling system a. Terminalunitscapableofprovidingcoolingshouldhaveintegratedorremotetimeandtemperaturecontrols.
b. Inanygivenzonesimultaneousheatingandcoolingshouldbepreventedbyaninterlock.
9.5 CalculatingtheseasonalenergyefficiencyratioforSBEMThevalueoftheSEERtobeusedintheSBEMtoolcanbecalculatedinanumberofwaysaccordingtotheavailabilityofinformationandtheapplication.
Ingeneral,whereanindustryapprovedtestprocedureforobtainingperformancemeasurementsofcoolingunitsatpartialloadconditionsexists,andthecoolingloadprofileoftheproposedbuildingisknown,theSEER ofthecoolingunitisgivenby:
SEERa(EER100%)b(EER
75%)c(EER
50%)d(EER
25%) Equation 10
where:
EERxistheEERmeasuredattheloadconditionsof100%,75%,50%and25%attheoperating
conditionsdetailedunderthepartloadenergyefficiencyratioinSection9.3
and:
a,b,canddaretheloadprofileweightingfactorsrelevanttotheproposedapplication.
ThefollowingsectionsdescribehowtheSEERmaybecalculatedforthespecificcasesof:
• coolingunitswithnopartloadperformancedata
• unknownloadprofiles
• office-typeaccommodation
• otherbuildingswithknownloadprofiledata
• multiple-chillersystems
• systemswithfreecoolingorheatrecovery
• absorptionchillersanddistrictcooling.
Cooling units with no part load performance data
Forcoolingunitsthathavenopartloaddata,theSEERisthefullloadEER.
Unknown load profiles
ForapplicationswheretheloadprofileunderwhichthecoolingplantoperatesisnotknownbutthereissomedataonchillerpartloadEER,then:
a. forchillerswherethefullandhalfload(50%)EERsareknown,theSEERistheaverageoftheEERs,i.e.the100%and50%areequallyweighted
b. forchillerswithfourpointsofpartloadEER,theSEERiscalculatedusingEquation10witheachEERweightedequally,i.e.a,b,canddeachequalto0.25
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c. ifthechilleruseddoesnothavedataforfourstepsofload,thentheweightsareapportionedappropriately.
Office-type accommodation
Forapplicationsingeneraloffice-typeaccommodation,thefollowingweightingfactorscanbetakenasrepresentativeoftheloadprofile:
a b c d
0.03 0.33 0.41 0.23
TheseweightingfactorsarethesameasthoseusedforthedeterminationoftheEuropeanSeasonalEnergyEfficiencyRatio(ESEER).MostmanufacturerspublishESEERfiguresandthesecanbeverifiedbyreferencetotheEuroventCertificationwebsiteatwww.eurovent-certification.com.TheESEERvalueisthenusedastheSEERintheSBEMcalculation.
Examples
1. ForasinglechillerwithEERof2.9(knownatfullloadonly):
SEER2.9
2. Forachillerwith100%and50%EERsof2.0and2.5respectivelyinabuildingwithunknownloadprofile:
SEER2.25
3. ForachillerwithunknownapplicationloadprofileandpartloadEERsofEER100%
2.89,EER75%
3.93,EER
50%4.89andEER
25%4.79:
SEER0.252.890.253.930.254.890.254.794.125
4. IfthesamechillerisusedinanofficethentheESEERweightingfactorsareused:
SEERESEER0.032.890.333.930.414.890.234.794.49
Other buildings with known load profile
Iftheloadprofileisknownfromdetailedsimulationorprediction,theSEERmaybederivedfromEquation10aboveusingappropriateweightsandEERsatgivenloads.
Multiple-chiller systems
Forplantswithmultiple-chillers,aplantseasonalenergyefficiencyratio(PSEER)valuemaybecalculatedbasedonthesumoftheenergyconsumptionsofalltheoperatingchillers.Inthiscasecaremustbetakentoincludeallthefactorsthatcaninfluencethecombinedperformanceofthemultiple-chillerinstallation.Thesewillincludethe:
• degreeofoversizingofthetotalinstalledcapacity
• sizesofindividualchillers
• EERsofindividualchillersatactualoperatingconditions
• controlmodeused:e.g.parallel,sequential,dedicatedlowloadunit
• loadprofileoftheproposedbuilding
• buildinglocation(asthisdeterminesambientconditions).
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WhentheseareknownitmaybepossibletocalculateaPSEERwhichmatchestheproposedinstallationmorecloselythanbyapplyingthesimplificationsdescribedearlier.ThisPSEERvalueisthenusedastheSEERintheSBEMcalculation.
Systems with free cooling or heat recovery
SystemsthathavetheabilitytousefreecoolingorheatrecoverycanachieveagreaterSEERthanmoreconventionalsystems.InthesecasestheSEERmustbederivedforthespecificapplicationunderconsideration.
Absorption chillers and district cooling
Absorptionchillersmaybeusedinconjunctionwithon-siteCHPoracommunityordistrictheatingsystem.ThecarbondioxideemissionsarecalculatedinthesamewayaswhenusingCHPforheating.Thecontrolsystemshouldensureasfaraspossiblethatheatfromboilersisnotusedtosupplytheabsorptionchiller.TheminimumfullloadEERoftheabsorptionchillersshouldbenoworsethan0.7.
Whereadistrictcoolingschemeexists,lowercarbondioxideemissionsmayresultifthecoolingisproducedcentrallyfromCHP/absorptionchillers,heatpumpsorhighefficiencyvapourcompressionchillers.Thedistrictcoolingcompanywillprovideinformationonthecarbondioxidecontentofthecoolingenergysupplied,andthisfigurecanthenbeusedtocalculatethecarbondioxideemissionrateforthebuilding.
9.6Supplementaryinformation
BSEN15243:200741providesadditionalguidanceoncalculatingtheseasonalefficiencyofcoldgeneratorsandchillersinairconditioningsystems.TheguidancedoesnotneedtobefollowedtomeetrelevantenergyefficiencyrequirementsintheBuildingRegulations.
41 BSEN15243:2007Ventilation for buildings. Calculation of room temperatures and of load and energy for buildings with room conditioning systems.
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Section10:Airdistribution
10.1 IntroductionThissectiongivesguidanceonspecifyingairdistributionsystemsfornewandexistingbuildingstomeetrelevantenergyefficiencyrequirementsintheBuildingRegulations.
10.2 ScopeofguidanceTheguidanceappliestothefollowingtypesofairdistributionsystem:
• centralairconditioningsystems
• centralmechanicalventilationsystemswithheating,coolingorheatrecovery
• allcentralsystemsnotcoveredbytheabovetwotypes
• zonalsupplysystemswherethefanisremotefromthezone,suchasceilingvoidorroof-mountedunits
• zonalextractsystemswherethefanisremotefromthezone
• localsupplyandextractventilationunitssuchaswindow,wallorroofunitsservingasinglearea(e.g.toiletextract)
• otherlocalventilationunits,e.g.fancoilunitsandfanassistedterminalvariableairvolume(VAV)units
• kitchenextract,fanremotefromzonewithgreasefilter.
Gasandoil-firedairheatersinstalledwithintheareatobeheatedarenotwithinthescopeofthissection.
10.3 KeytermsAirconditioningsystem means acombinationofcomponentsrequiredtoprovideaformofairtreatmentinwhichtemperatureiscontrolledorcanbelowered,possiblyincombinationwiththecontrolofventilation,humidityandaircleanliness.
Ventilationsystem means acombinationofcomponentsrequiredtoprovideairtreatmentinwhichtemperature,ventilationandaircleanlinessarecontrolled.
Centralsystemmeans asupplyandextractsystemwhichservesthewholeormajorzonesofthebuilding.
Localunit means anunductedventilationunitservingasinglearea.
Zonalsystem means asystemwhichservesagroupofroomsformingpartofabuilding,i.e.azonewhereductingisrequired.
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Demandcontrol isatypeofcontrolwheretheventilationrateiscontrolledbyairquality,moisture,occupancyorsomeotherindicatoroftheneedforventilation.
Specificfanpower(SFP) ofanairdistributionsystem means thesumofthedesigncircuit-wattsofthesystemfansthatsupplyairandexhaustitbackoutdoors,includinglossesthroughswitchgearandcontrolssuchasinverters(i.e.thetotalcircuit-wattsforthesupplyandextractfans),dividedbythedesignairflowratethroughthatsystem.
Forthepurposesofthisguide,thespecificfanpowerofanairdistributionsystemshouldbecalculatedaccordingtotheproceduresetoutinBSEN13779:200742AnnexDCalculation and application of specific fan power. Calculating and checking the SFP, SFP
E and SFP
V.
SFP P
sfP
ef Equation 11q
where:
SFPisthespecificfanpowerdemandoftheairdistributionsystem(W/(l.s))
Psf isthetotalfanpowerofallsupplyairfansatthedesignairflowrate,includingpowerlosses
throughswitchgearandcontrolsassociatedwithpoweringandcontrollingthefans(W)
Pefisthetotalfanpowerofallexhaustairfansatthedesignairflowrateincludingpowerlosses
throughswitchgearandcontrolsassociatedwithpoweringandcontrollingthefans(W)
q isthedesignairflowratethroughthesystem,whichshouldbethegreaterofeitherthesupplyorexhaustairflow(l/s).Notethatforanairhandlingunit,qisthelargestsupplyorextractairflowthroughtheunit.
Externalsystempressuredrop means thetotalsystempressuredropexcludingthepressuredropacrosstheairhandlingunit.
10.4 AirdistributionsystemsinnewandexistingbuildingsAirdistributionsystemsinnewandexistingbuildingsshouldmeetthefollowingrecommendedminimumstandards:
a. Airhandlingsystemsshouldbecapableofachievingaspecificfanpowerat25%ofdesignflowratenogreaterthanthatachievedat100%designflowrate.
b. Inordertoaidcommissioningandtoprovideflexibilityforfuturechangesofuse,reasonableprovisionwouldbetoequipwithvariablespeeddrivesthosefansthatareratedatmorethan1100Wandwhichformpartoftheenvironmentalcontrolsystems,includingsmokecontrolfansusedforcontrolofoverheating.Theprovisionisnotapplicabletosmokecontrolfansandsimilarventilationsystemsonlyusedinabnormalcircumstances.
42 BSEN13779:2007Ventilation for non-residential buildings. Performance requirements for ventilation and room-conditioning systems.
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c. Inordertolimitairleakage,ventilationductworkshouldbemadeandassembledsoastobereasonablyairtight.Waysofmeetingthisrequirementwouldbetocomplywiththespecificationsgivenin:
i. B&ESDW/14443.MembershipoftheB&ESspecialistductworkgrouportheAssociationofDuctworkContractorsandAlliedServicesisonewayofdemonstratingsuitablequalifications,or
ii. BritishStandardssuchasBSEN1507:200644,BSEN12237:200345andBSEN13403:200346.
d. Inordertolimitairleakage,airhandlingunitsshouldbemadeandassembledsoastobereasonablyairtight.WaysofmeetingthisrequirementwouldbetocomplywithClassL2airleakagegiveninBSEN1886:200747.
e. ThespecificfanpowerofairdistributionsystemsatthedesignairflowrateshouldbenoworsethaninTable35fornewandexistingbuildings.Specificfanpowerisafunctionofthesystemresistancethatthefanhastoovercometoprovidetherequiredflowrate.BSEN13779TableA8providesguidanceonsystempressuredrop.Tominimisespecificfanpoweritisrecommendedthatthe‘lowrange’isusedasadesigntarget.
f. WheretheprimaryairandcoolingisprovidedbycentralplantandbyanairdistributionsystemthatincludestheadditionalcomponentslistedinTable36,theallowedspecificfanpowersmaybeincreasedbytheamountsshowninTable36toaccountfortheadditionalresistance.
g. AminimumcontrolspackageshouldbeprovidedinnewandexistingbuildingsasinTable37.
h. VentilationfansdrivenbyelectricmotorsshouldcomplywithEuropeanCommissionRegulationNo327/2011implementingDirective2009/125/ECwithregardtoecodesignrequirementsforfansdrivenbymotorswithanelectricinputpowerbetween125Wand500kW.
43 DuctworkSpecificationDW/144Specifications for sheet metal ductwork. Low, medium and high pressure/velocity air system,B&ES,2013.44 BSEN1507:2006Ventilation for buildings. Sheet metal air ducts with rectangular section. Requirements for strength and leakage.45 BSEN12237:2003Ventilation for buildings. Ductwork. Strength and leakage of circular sheet metal ducts.46 BSEN13403:2003Ventilation for buildings. Non-metallic ducts. Ductwork made from insulation ductboards.47 BSEN1886:2007Ventilation for buildings. Air handling units. Mechanical performance.
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Table 35 Maximum specific fan power in air distribution systems in new and existing buildings
System type SFP(W/(l.s))
New buildings
Existing buildings
Centralbalancedmechanicalventilationsystemwithheatingandcooling 1.6 2.2
Centralbalancedmechanicalventilationsystemwithheatingonly 1.5 1.8
Allothercentralbalancedmechanicalventilationsystems 1.1 1.6
Zonalsupplysystemwherefanisremotefromzone,suchasceilingvoidorroof-mountedunits
1.1 1.4
Zonalextractsystemwherefanisremotefromzone 0.5 0.5
Zonalsupplyandextractventilationunits,suchasceilingvoidorroofunitsservingsingleroomorzonewithheatingandheatrecovery
1.9 1.9
Localbalancedsupplyandextractventilationsystemsuchaswall/roofunitsservingsingleareawithheatrecovery
1.6 1.6
Localsupplyorextractventilationunitssuchaswindow/wall/roofunitsservingsinglearea(e.g.toiletextract)
0.3 0.4
Otherlocalventilationsupplyorextractunits 0.5 0.5
FanassistedterminalVAVunit 1.1 1.1
Fancoilunit(ratingweightedaverage*) 0.5 0.5
Kitchenextract,fanremotefromzonewithgreasefilter 1.0 1.0
*Theratingweightedaverageiscalculatedbythefollowingformula:
Pmains,1
SFP1P
mains,2SFP
2P
mains,3SFP
3...
Pmains,1
Pmains,2
Pmains,3
...
wherePmains
isusefulpowersuppliedfromthemainsinW.
Table 36 Extending specific fan power for additional components in new and existing buildings
Component SFP(W/(l.s))
Additionalreturnfilterforheatrecovery +0.1
HEPAfilter +1.0
Heatrecovery–thermalwheelsystem +0.3
Heatrecovery–othersystems +0.3
Humidifier/dehumidifier(airconditioningsystem) +0.1
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Example:
Foracentralmechanicalventilationsystemwithheatingandcooling,andheatrecoveryviaaplateheatexchangerplusreturnfilter:
SFP 1.60.30.1W/(l.s)
2.0W/(l.s)
Table 37 Recommended minimum controls for air distribution systems in new and existing buildings from BS EN 15232:201248
System type Controls package
Central mechanical ventilation with heating, cooling or heat recovery
Airflowcontrolatroomlevel Timecontrol
Airflowcontrolatairhandlerlevel On/offtimecontrol
Heatexchangerdefrostingcontrol Defrostcontrolsothatduringcoldperiodsicedoesnotformontheheatexchanger
Heatexchangeroverheatingcontrol Overheatingcontrolsothatwhenthesystemiscoolingandheatrecoveryisundesirable,theheatexchangerisstopped,modulatedorbypassed
Supplytemperaturecontrol Variablesetpointwithoutdoortemperaturecompensation
Central mechanical ventilation with heating or heat recovery
Airflowcontrolatroomlevel Timecontrol
Airflowcontrolatairhandlerlevel On/offtimecontrol
Heatexchangerdefrostingcontrol Defrostcontrolsothatduringcoldperiodsicedoesnotformontheheatexchanger
Heatexchangeroverheatingcontrol Overheatingcontrolsothatwhenthesystemiscoolingandheatrecoveryisundesirable,theheatexchangerisstopped,modulatedorbypassed
Supplytemperaturecontrol Demandcontrol
Zonal Airflowcontrolatroomlevel On/offtimecontrol
Airflowcontrolatairhandlerlevel Nocontrol
Supplytemperaturecontrol Nocontrol
Local Airflowcontrolatroomlevel On/off
Airflowcontrolatairhandlerlevel Nocontrol
Supplytemperaturecontrol Nocontrol
48 BSEN15232:2012Energy performance of buildings. Impact of building automation, controls and building management.
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10.5 HeatrecoveryinairdistributionsystemsinnewandexistingbuildingsAirsupplyandextractventilationsystemsincludingheatingorcoolingshouldbefittedwithaheatrecoverysystem.Theapplicationofaheatrecoverysystemisdescribedin6.5ofBSEN13053:2006+A1:201149.Themethodsfortestingair-to-airheatrecoverydevicesaregiveninBSEN308:199750.
Theminimumdryheatrecoveryefficiencywithreferencetothemassflowratio1:1shouldbenolessthanthatrecommendedinTable38.
Table 38 Recommended minimum dry heat recovery efficiency for heat exchangers in new and existing buildings
Heat exchanger type Dry heat recovery efficiency (%)
Plateheatexchanger 50
Heatpipes 60
Thermalwheel 65
Runaroundcoil 45
10.6 CalculatingthespecificfanpowerforSBEMSBEMassumesavalueofSFPforthefancoilsystem,sothisfigureshouldnotbeaddedtotheSFPforthefancoilunitswhenenteringthedataintoSBEM.
HEPAfiltrationisrecognisedasanoptioninSBEM.ThepressuredropcanbespecifiedorSBEMwillassumeadefaultvaluefromtheNCMactivitydatabase.
49 BSEN13053:2006+A1:2011Ventilation for buildings. Air handling units. Rating and performance for units, components and sections.50 BSEN308:1997Heat exchangers. Test procedures for establishing the performance of air to air and flue gases heat recovery devices.
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Section11:Pipeworkandductworkinsulation
11.1IntroductionThissectiongivesguidanceoninsulatingpipeworkandductingservingspaceheating,hotwaterandcoolingsystemsinnewandexistingbuildingstomeetrelevantenergyefficiencyrequirementsintheBuildingRegulations.
Theinsulationofpipeworkandductingisessentialtominimiseheatingsystemheatlossesandcoolingsystemheatgains.Forcoolingsystems,itisalsoimportanttoensurethattheriskofcondensationisadequatelycontrolled.
11.2ScopeofguidanceTheguidanceinthissectioncoversinsulationforthefollowingtypesofpipeworkandductworkservingspaceheating,domestichotwaterandcoolingsystems:
• pipework:directhotwater,low,mediumandhightemperatureheating,andcooled
• ductwork:heated,cooledanddual-purposeheatedandcooled.
11.3InsulationofpipesandductsinnewandexistingbuildingsInsulationofpipesandductsservingheatingandcoolingsystemsshouldmeetthefollowingrecommendedminimumstandards.TherelevantstandardforcalculatinginsulationthicknessisBSENISO12241:200851.
a. Direct hot water and heating pipework
i. Pipeworkservingspaceheatingandhotwatersystemsshouldbeinsulatedinallareasoutsideoftheheatedbuildingenvelope.Inaddition,pipesshouldbeinsulatedinallvoidswithinthebuildingenvelopeandwithinspaceswhichwillnormallybeheated,ifthereisapossibilitythatthosespacesmightbemaintainedattemperaturesdifferenttothosemaintainedinotherzones.Theguidingprinciplesarethatcontrolshouldbemaximisedandthatheatlossfromuninsulatedpipesshouldonlybepermittedwheretheheatcanbedemonstratedas‘alwaysuseful’.
ii. Inordertodemonstratecompliance,theheatlossesshowninTable39fordifferentpipesizesandtemperaturesshouldnotbeexceeded.
b. Cooling pipework
i. Coolingpipeworkshouldbeinsulatedalongitswholelengthinordertoprovidethenecessarymeansoflimitingheatgain.Controlshouldbemaximisedandheatgaintouninsulatedpipesshouldonlybepermittedwheretheproportionofthecoolingloadrelatingtodistributionpipeworkisproventobelessthan1%oftotalload.
ii. Inordertodemonstratecompliance,theheatgainsinTable40fordifferentpipesizesandtemperaturesshouldnotbeexceeded.
iii. AlthoughunrelatedtomeetingrelevantenergyefficiencyrequirementsintheBuildingRegulations,provisionshouldalsobemadeforcontrolofcondensationbyfollowingTIMSAguidance52.
51 BSENISO12241:2008.Thermal insulation for building equipment and industrial installations. Calculation rules.52 TIMSAHVAC guidance for achieving compliance with Part L of the Building Regulations.
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c. Heating and cooling ductwork
i. Ductingshouldbeinsulatedalongitswholelengthinordertoprovidethenecessarymeansoflimitingheatgainsorheatlosses.
ii. TheheatlossesorgainsperunitareashouldnotexceedthevaluesinTable41.Whereductingmaybeusedforbothheatingandcooling,thelimitsforchilledductingshouldbeadoptedsincethesearemoreonerous.(Heatgainsareshownasnegativevalues.)
iii. Aswithpipework,additionalinsulationmayberequiredtoprovideadequatecondensationcontrol,asdetailedinTIMSAguidance.
Table 39 Recommended maximum heat losses for direct hot water and heating pipes
Heat loss (W/m)
Outside pipe diameter (mm) Hot water[1]
Low temperature heating[2]
Medium temperature heating[3]
High temperature heating[4]
95°C 96°Cto120°C 121°Cto150°C
17.2 6.60 8.90 13.34 17.92
21.3 7.13 9.28 13.56 18.32
26.9 7.83 10.06 13.83 18.70
33.7 8.62 11.07 14.39 19.02
42.4 9.72 12.30 15.66 19.25
48.3 10.21 12.94 16.67 20.17
60.3 11.57 14.45 18.25 21.96
76.1 13.09 16.35 20.42 24.21
88.9 14.58 17.91 22.09 25.99
114.3 17.20 20.77 25.31 29.32
139.7 19.65 23.71 28.23 32.47
168.3 22.31 26.89 31.61 36.04
219.1 27.52 32.54 37.66 42.16
273.0 32.40 38.83 43.72 48.48
NoteToensurecompliancewiththemaximumheatlosscriteria,insulationthicknessesshouldbecalculatedaccordingtoBSENISO12241usingstandardisedassumptions:[1] Horizontalpipeat60°Cinstillairat15°C[2] Horizontalpipeat75°Cinstillairat15°C[3] Horizontalpipeat100°Cinstillairat15°C[4] Horizontalpipeat125°Cinstillairat15°C
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Table 40 Recommended maximum heat gains for cooled water supply pipes
Outside diameter of steel pipe on which insulation has been based (mm)
Heat gain (W/m)
Temperature of contents (°C)
10[1] 4.9 to 10.0[2] 0 to 4.9[3]
17.2 2.48 2.97 3.47
21.3 2.72 3.27 3.81
26.9 3.05 3.58 4.18
33.7 3.41 4.01 4.60
42.4 3.86 4.53 5.11
48.3 4.11 4.82 5.45
60.3 4.78 5.48 6.17
76.1 5.51 6.30 6.70
88.9 6.17 6.90 7.77
114.3 7.28 8.31 9.15
139.7 8.52 9.49 10.45
168.3 9.89 10.97 11.86
219.1 12.27 13.57 14.61
273.0 14.74 16.28 17.48
NoteToensurecompliancewiththemaximumheatgaincriteria,insulationthicknessesshouldbecalculatedaccordingtoBSENISO12241usingstandardisedassumptions:[1] Horizontalpipeat10°Cinstillairat25°C[2] Horizontalpipeat5°Cinstillairat25°C[3] Horizontalpipeat0°Cinstillairat25°C
Table 41 Recommended maximum heat losses and gains for insulated heating, cooling and dual-purpose ducts
Heating duct[1] Dual-purpose duct[2] Cooling duct[3]
Heattransfer(W/m2) 16.34 -6.45 -6.45
NoteToensurecompliancewithmaximumheattransfercriteria,insulationthicknessesshouldbecalculatedaccordingtoBSENISO12241usingstandardisedassumptions:[1] Horizontalductat35°C,with600mmverticalsidewallinstillairat15°C[2] Horizontalductat13°C,with600mmverticalsidewallinstillairat25°C[3] Horizontalductat13°C,with600mmverticalsidewallinstillairat25°C
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Section 12: Lighting
Section12:Lighting
12.1 IntroductionThissectionprovidesguidanceonspecifyinglightingfornewandexistingnon-domesticbuildingstomeetrelevantenergyefficiencyrequirementsintheBuildingRegulations.Therearetwoalternativeapproaches,applicablebothtosystemsinnewbuildingsandtoreplacementsystemsinexistingbuildings.
12.2 ScopeofguidanceTheguidanceinthissectionappliestothefollowingtypesoflighting:
• generalinteriorlighting
• displaylighting.
12.3 KeytermsOfficearea means aspacethatinvolvespredominantlydesk-basedtasks–e.g.aclassroom,seminarorconferenceroom.
Daylitspace meansanyspace:
a. within6mofawindowwall,providedthattheglazingareaisatleast20%oftheinternalareaofthewindowwall
b. belowrooflights,providedthattheglazingareaisatleast10%ofthefloorarea.
Thenormallighttransmittanceoftheglazingshouldbeatleast70%;ifthelighttransmittanceisbelow70%,theglazingareashouldbeincreasedproportionatelyforthespacetobedefinedasdaylit.
Spaceclassification forcontrolpurposes53:
Ownedspace means aspacesuchasasmallroomforoneortwopeoplewhocontrolthelighting–e.g.acellularofficeorconsultingroom.
Sharedspace means amulti-occupiedarea–e.g.anopen-planofficeorfactoryproductionarea.
Temporarilyownedspace means aspacewherepeopleareexpectedtooperatethelightingcontrolswhiletheyarethere–e.g.ahotelroomormeetingroom.
Occasionallyvisitedspace means aspacewherepeoplegenerallystayforarelativelyshortperiodoftimewhentheyvisitthespace–e.g.astoreroomortoilet.
Unownedspace means aspacewhereindividualusersrequirelightingbutarenotexpectedtooperatethelightingcontrols–e.g.acorridororatrium.
Managedspace means aspacewherelightingisunderthecontrolofaresponsibleperson–e.g.ahotellounge,restaurantorshop.
Localmanualswitching meansthatthedistanceonplanfromanylocalswitchtotheluminaireitcontrolsshouldgenerallybenotmorethan6m,ortwicetheheightofthelightfittingabovethefloorifthisisgreater.Wherethespaceisadaylitspaceservedbysidewindows,theperimeterrowoflightingshouldingeneralbeseparatelyswitched.
53 ThesedefinitionsaregiveninmoredetailinBREInformationPaperIP6/96People and lighting controlsandBREDigest498Selecting lighting controls.
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Photoelectriccontrol isatypeofcontrolwhichswitchesordimslightinginresponsetotheamountofincomingdaylight.
Presencedetection isatypeofcontrolwhichswitchesthelightingonwhensomeoneentersaspace,andswitchesitoff,ordimsitdown,afterthespacebecomesunoccupied.
Absencedetection isatypeofcontrolwhichswitchesthelightingoff,ordimsitdown,afterthespacebecomesunoccupied,butwhereswitchingonisdonemanually.
Lamplumens means thesumoftheaverageinitial(100hour)lumenoutputofallthelampsintheluminaire.
Circuit-watt isthepowerconsumedinlightingcircuitsbylampsand,whereapplicable,theirassociatedcontrolgear(includingtransformersanddrivers)andpowerfactorcorrectionequipment.
Lamplumenspercircuit-watt isthetotallamplumenssummedforallluminairesintherelevantareasofthebuilding,dividedbythetotalcircuit-wattsforalltheluminaires.
LOR isthelightoutputratiooftheluminaire,whichmeanstheratioofthetotallightoutputoftheluminaireunderstatedpracticalconditionstothatofthelamporlampscontainedintheluminaireunderreferenceconditions.
Luminairelumenspercircuit-watt isthe(lamplumensLOR)summedforallluminairesintherelevantareasofthebuilding,dividedbythetotalcircuit-wattsforalltheluminaires.
LENI(LightingEnergyNumericIndicator)isameasureoftheperformanceoflightingintermsofenergypersquaremetreperyear(kWh/m2/year),basedonBSEN15193:2007Energy performance of buildings. Energy requirements for lighting.
12.4 Lightinginnewandexistingbuildingsa. Lightinginnewandexistingbuildingsshouldmeettherecommendedminimumstandardsfor:
i. efficacy(averagedoverthewholeareaoftheapplicabletypeofspaceinthebuilding)andcontrolsinTable42
OR
ii. theLENIinTable44.TheLENIshouldbecalculatedusingtheproceduredescribedinSection12.5.
b. ThelightingshouldbemeteredtorecorditsenergyconsumptioninaccordancewiththeminimumstandardsinTable43.
c. LightingcontrolsinnewandexistingbuildingsshouldfollowtheguidanceinBREDigest498Selecting lighting controls.Displaylighting,whereprovided,shouldbecontrolledondedicatedcircuitsthatcanbeswitchedoffattimeswhenpeoplewillnotbeinspectingexhibitsormerchandise,orbeingentertained.
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Table 42 Recommended minimum lighting efficacy with controls in new and existing buildings
General lighting in office, industrial and storage spaces
Initial luminaire lumens/circuit-watt
60
Controls Control factor Reduced luminaire lumens/circuit-watt
a daylitspacewithphoto-switchingwithorwithoutoverride
0.90 54
b daylitspacewithphoto-switchinganddimmingwithorwithoutoverride
0.85 51
c unoccupiedspacewithautoonandoff 0.90 54
d unoccupiedspacewithmanualonandautooff 0.85 51
e spacenotdaylit,dimmedforconstantilluminance 0.90 54
ac 0.80 48
ad 0.75 45
bc 0.75 45
bd 0.70 42
ec 0.80 48
ed 0.75 45
Generallightinginothertypesofspace Theaverageinitialefficacyshouldbenotlessthan60lamplumenspercircuit-watt
Displaylighting Theaverageinitialefficacyshouldbenotlessthan22lamplumenspercircuit-watt
Table 43 Recommended minimum standards for metering of general and display lighting in new and existing buildings
Standard
Metering for general or display lighting
a. kWhmetersondedicatedlightingcircuitsintheelectricaldistribution,orb. localpowermetercoupledtoorintegratedinthelightingcontrollersofalightingor
buildingmanagementsystem,orc. alightingmanagementsystemthatcancalculatetheconsumedenergyandmakethis
informationavailabletoabuildingmanagementsystemorinanexportablefileformat.(Thiscouldinvolveloggingthehoursrunandthedimminglevel,andrelatingthistotheinstalledload.)
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12.5 LightingEnergyNumericIndicator(LENI)AnalternativetocomplyingwiththeefficacystandardsinTable42istofollowtheLightingEnergyNumericIndicator(LENI)method.
TheLENImethodcalculatestheperformanceoflightingintermsofenergypersquaremetreperyear.TheapproachdescribedbelowmustbefollowedincalculatingtheLENIforalightingscheme.TheLENIshouldnotexceedthelightingenergylimitspecifiedinTable44foragivenilluminanceandhoursrun.
Design the lighting
Thefirststeptoenergyefficientlightingistodesignthelightinginstallationinawaythatmeetsalloftheusers’needsforthespaceunderconsideration.RecommendationsforappropriateilluminancevaluesandotherlightingrequirementsmaybefoundinBSEN12464-1:201154,andintheSocietyofLightandLighting(SLL)Code for Lighting. The SLL Lighting Handbookprovidespracticaladviceonhowtodesignlightingforanumberofdifferentapplications55.
Look up the lighting energy limit
Indesigningthelighting,alevelofilluminancewillhavebeenselectedasnecessaryforthetasksbeingdoneinaparticulararea.Itisalsonecessarytodeterminehowmanyhoursperyearthelightingwillbeneeded.OnceboththeilluminanceandthehoursareknownitispossibletolookupthelightingenergylimitinTable44.Forexample,aclassroominaschoolmaybelitto300luxandusedfor40hoursperweekfor39weeksoftheyear,givingatotalof1560hoursperyear.Valuesof1500hoursand300luxgivealightingenergylimitof7.70.Table44alsogivesday-time(Td
)andnight-time(Tn)hourvalueswhichare
usedinthecalculationofenergyconsumption.
Ifdisplaylightingisused,thenthelightingenergylimitmaybeincreasedbythevaluegivenfornormaldisplaylightingfortheareaoftheroomwheredisplaylightingisused.Forexample,inanentranceareaforabuildingtheremaybesomedisplaylightinginasmallareaaroundthereceptiondeskbutnotintherestofthearea.
Shopwindowsusealotofdisplaylightingandmayuseupto192.72kWh/m2/yearifthewindowfacesapublicroad,and96.8kWh/m2/yearifthewindowisinashoppingcentrethatisclosedduringthenight.
Calculate the parasitic energy use (Ep)
Ifsomeformoflightingcontrolsystemisused,thenanallowanceneedstobemadefortheenergyusedbythecontrolsystem,andthefactthattheluminairestakealittlepowereveniftheyaredimmeddowntogivenolight.Anallowanceof0.3W/m2shouldbemadeforpowerusedinthisway.Ifthewholelightingsystemisswitchedoffwhentheroomisnotinuse,thenthepowerlossisonlyduringthehoursofuse.Ifthesystemisleftonallthetimethenthepowerlossoccursfor8760hoursperyear.
Ifnolightingcontrolsystemisused,thentheparasiticenergyuseiszero.
Determine the total power of lighting (Pl)
Thisisthetotalpowerinwattsconsumedbytheluminaireswithinaspace.
54 BSEN12464-1:2011. Light and lighting. Lighting of work places. Indoor work places.55 Forfurtherinformation,seewww.sll.org.ukandwww.thelia.org.uk.
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Determine the occupancy factor (Fo)
Foallowsforthefactthatenergyissavedifanautomaticcontrolsystemdetectsthepresenceorabsence
ofpeopleinaroomandswitchesoffthelightswhenthereisnobodyusingtheroom.Ifnoautomaticcontrolisused,thentheoccupancyfactorF
o1.Ifcontrolsturnoffthelightswithin20minutesofthe
roombeingempty,thenFo0.8.
Determine the factor for daylight (Fd)
Fdallowsforthefactthatifthelightingisdimmeddownwhenthereisdaylightavailable,thenless
energywillbeused.Ifnodaylight-linkeddimmingsystemisused,thenFd1.Iftheelectriclightingdims
inresponsetodaylightbeingavailable,theninareaswithadequatedaylightFd0.8.Adequatedaylight
maybefoundinareasthatarewithin6mofawindowwallorinareaswhere10%ormoreoftheroofistranslucentormadeupofrooflights.
Determine the constant illuminance factor (Fc)
Whenlightingisdesigned,amaintenancefactor(MF)isusedtoallowforthefactthatasthelightingsystemagesitproduceslesslight.Thismeansthatondayonethelightingsystemisprovidingmorelightthanneeded.Thuswithaconstantilluminancesystem,itispossibletounder-runthelightingondayone,andthenslowlyincreasethepowerusedbythelightinguntilthepointisreachedwhenmaintenanceneedstobecarriedoutbychangingthelampsorcleaningtheluminaires.SystemsthatcontrolthelightinginthiswayhaveanFc
0.9,andthosethatdonothaveanFc1.
Calculate the daytime energy use (Ed)
Thedaytimeenergyuseis:
Ed PlFoFdFcTd
1000
Calculate the night-time energy use (En)
Thenight-timeenergyuseis:
En PlFoFcTn
1000
Calculate total energy (kWh) per square metre per year (LENI)
Thetotalenergypersquaremetreperyearisthesumofthedaytime,night-timeandparasiticenergyusesperyeardividedbythearea(A),assetoutintheformulabelow:
LENI EpEdEn
A
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Table 44 Recommended maximum LENI (kWh per square metre per year) in new and existing buildings
Hours Illuminance (lux) Display lighting
Total Day Night 50 100 150 200 300 500 750 1000 NormalShopwindow
1000 821 179 1.11 1.92 2.73 3.54 5.17 8.41 12.47 16.52 10.00
1500 1277 223 1.66 2.87 4.07 5.28 7.70 12.53 18.57 24.62 15.00
2000 1726 274 2.21 3.81 5.42 7.03 10.24 16.67 24.70 32.73 20.00
2500 2164 336 2.76 4.76 6.77 8.78 12.79 20.82 30.86 40.89 25.00
3000 2585 415 3.31 5.72 8.13 10.54 15.37 25.01 37.06 49.12 30.00
3700 3133 567 4.09 7.08 10.06 13.04 19.01 30.95 45.87 60.78 37.00
4400 3621 779 4.89 8.46 12.02 15.59 22.73 37.00 54.84 72.68 44.00 96.80
5400 4184 1216 6.05 10.47 14.90 19.33 28.18 45.89 68.03 90.17 54.00
6400 4547 1853 7.24 12.57 17.89 23.22 33.87 55.16 81.79 108.41 64.00
8760 4380 4380 10.26 17.89 25.53 33.16 48.43 78.96 117.12 155.29 87.60 192.72
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Section 13: Heating and cooling system circulators and water pumps
Section13:Heatingandcoolingsystemcirculatorsandwaterpumps13.1 IntroductionHeatingandcoolingwaterinHVACsystemsofnon-domesticbuildingscancirculateforextensiveperiodsandberesponsibleforconsiderableenergyuse.
13.2 ScopeofguidanceThissectionprovidesguidanceonspecifying:
• heatingsystemglandlesscirculators,bothstandaloneandintegratedinproducts
• heatingandcoolingsystemwaterpumps
tolimittheirenergyconsumptionandmeetrelevantenergyefficiencyrequirementsintheBuildingRegulations.Theguidancecoverscirculatorsandwaterpumpswhenusedinclosedsystems.
13.3 KeytermsHeatingsystemglandlesscirculator means apumpusedtocirculatehotwaterinclosedcircuitheatingsystems.Theglandless(orwetrotor)circulatorisacentrifugalpumpwithanintegralmotorandnomechanicalseal.Itcanhaveanintegratedmotordriveunitforvariablespeedoperation.
Waterpump (alsoknownas‘dryrotor’or‘directcoupled’pump) means acentrifugalpumpdrivenbyanelectricmotorandgenerallyhavingmechanicalseals.Commonpumptypesincludein-line,endsuctionandverticalmulti-stage.Thefirsttwoareusuallysingle-stagepumpshavingsingle-entryvolute.BydesigntheycanallbeusedascirculatorsforallHVACapplicationsdependingonconfigurationandduty.
13.4 GlandlesscirculatorsandwaterpumpsinnewandexistingbuildingsHeatingsystemglandlesscirculatorsandheatingandcoolingsystemwaterpumpsinnewandexistingbuildingsshouldmeettherecommendedminimumstandardsinTable45.
Table 45 Recommended minimum standards for heating system glandless circulators and heating and cooling system water pumps in new and existing buildings
a. InaccordancewithEuropeanCommissionRegulationNo622/2012(amending641/2009)implementingDirective2009/125/ECwithregardtoecodesignrequirementsforglandlesscirculatorsupto2.5kW:
i. From1January2013,standaloneglandlesscirculators,otherthanthosespecificallydesignedforprimarycircuitsofthermalsolarsystemsandofheatpumps,shouldhaveanEnergyEfficiencyIndex(EEI)nogreaterthan0.27.
ii. From1August2015,standaloneglandlesscirculatorsandglandlesscirculatorsintegratedinproductsshouldhaveanEnergyEfficiencyIndex(EEI)nogreaterthan0.23.
b. Variablespeedglandlesscirculatorsshouldbeusedonvariablevolumesystems.
c. WaterpumpsshouldcomplywiththerequirementsofEuropeanCommissionRegulationNo547/2012implementingDirective2009/125/ECwithregardtoecodesignrequirementsforwaterpumps.
d. Ifawaterpumpisusedonaclosedloopcircuitandthemotorisratedatmorethan750W,thenitshouldbefittedwithorcontrolledbyanappropriatevariablespeedcontrolleronanyvariablevolumesystem.Onwaterpumpboostersetswithanopenloopcircuit,thestaticheadshouldbecheckedbeforeanappropriatevariablespeedcontrollerisused.
13.5 Supplementaryinformation
Furtherinformationandguidanceisavailablefromwww.bpma.org.ukwherealistofapprovedglandlesscirculatorsandwaterpumpscanbefound.
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Non-Domestic Building Services Compliance Guide: 2013 Edition
AppendixA:Abbreviations
BER BuildingcarbondioxideemissionrateBMS BuildingmanagementsystemBS BritishStandardCHP CombinedheatandpowerCHPQA CombinedHeatandPowerQualityAssuranceCO
2 Carbondioxide
COP CoefficientofperformanceDCLG DepartmentforCommunitiesandLocalGovernmentDECC DepartmentofEnergyandClimateChangeDHW DomestichotwaterEEI EnergyEfficiencyIndexEER EnergyefficiencyratioEN EuropeanNorm(standard)ESEER EuropeanSeasonalEnergyEfficiencyRatioHEPA High-efficiencyparticulateabsorptionHVAC Heating,ventilationandairconditioningLENI LightingEnergyNumericIndicatorLPG LiquifiedpetroleumgasMF MaintenancefactorNCM NationalCalculationMethodologyPSEER PlantseasonalenergyefficiencyratioQI QualityindexRHI RenewableHeatIncentiveSAP StandardAssessmentProcedureSBEM SimplifiedBuildingEnergyModelSCOP SeasonalcoefficientofperformanceSEER SeasonalenergyefficiencyratioSFP SpecificfanpowerSI StatutoryInstrumentSPEER SeasonalprimaryenergyefficiencyratioSPF SeasonalperformancefactorTER TargetcarbondioxideemissionrateTRV ThermostaticradiatorvalveVAV Variableairvolume
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