Outreach Energy and Water Efficiency Program · to Housing ACT for draught sealing and ceiling...
Transcript of Outreach Energy and Water Efficiency Program · to Housing ACT for draught sealing and ceiling...
Outreach Energy and Water Efficiency Program
Case study report
JUNE 2013
environment.act.gov.au 1
Contents
Further information 2
Summary 3
1 Background 51.1 TheOutreachEnergyandWaterEfficiencyProgram 51.2 Projectaims 5
2 Methodology 72.1 Recruitmentofcasestudyparticipants 72.2 Tools 72.3 Datacollectiontimeline 7
3 Results 113.1 Characteristicsofcasestudyparticipants 113.2 Thermalperformancesimulation 123.3 Airleakagerateandlocation 143.4 Thermographicinspectionofinsulation 163.5 Temperatureandenergymonitoring 173.6 Appliancereplacement 193.7 Householdenergybills 203.8 Costandgreenhousegassavings 233.9 Householdcompositionandbehaviour 243.10 Typeofheatingsystem 253.11 Clientresponsestoenergymonitors 25
4 Findings and recommendations 274.1 Thermalperformancesimulation 274.2 Airleakagerateandlocation 274.3 Insulation 284.4 Temperature 284.5 Appliancereplacement 284.6 Householdenergyuse 284.7 Costandgreenhousegassavings 294.8 Householdcompositionandbehaviour 294.9 Clientresponsestoenergymonitors 29
Appendix A 31Casestudy1 31Casestudy2 37Casestudy3 41Casestudy4 44Casestudy5 49Casestudy6 54Casestudy7 58Casestudy8 62Casestudy9 65Casestudy10 68Casestudy11 70
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Further informationForfurtherinformationonthisreport,pleasecontact:
EnvironmentandSustainableDevelopmentDirectorate
Telephone:132281
Facsimile:62072316
Website:www.environment.act.gov.au/water
©AustralianCapitalTerritory,Canberra2013
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Disclaimer:ESDDdoesnotguaranteethatthedataisfreefromerrors.
PublishedbytheACTGovernmentEnvironmentandSustainableDevelopmentDirectorate
AcknowledgementsTheOutreachEnergyandWaterEfficiencyProgramforthesecasestudieswasdeliveredbyenergyefficiencyofficersonbehalfofthefollowingcommunitywelfareorganisations:
BelconnenCommunityService
Communities@Work
NorthsideCommunityService
SocietyofStVincentdePaul
YWCAofCanberra.
AssessorsandretrofittersfromC&JGroupandCoolPlanetprovidedenergyandwaterefficiencyassessments,educationandretrofittingfortheOutreachProgram.StafffromHousingACTcoordinatedtheenergyefficiencyimprovementsonHousingACTproperties.
Prepared byScinergy:theScienceofEnergyEfficiency
EditedbyBiotextPtyLtd,Canberra
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Summary
BetweenMarchandSeptember2012,Scinergyconducteddiagnosticassessmentsandanalysisonasampleof11low-incomehouseholdsparticipatingintheACTGovernment’sOutreachEnergyandWaterEfficiencyProgram.
TheaimsoftheprojectweretocollectandanalysedatatodeterminewhethertheOutreachProgramisimprovinghouseholdenergyefficiency,andtoinformandimprovepolicyandprogramimplementation.Theprojectincluded:
• analysingthethermalperformanceofthebuildingenvelopeforeachcasestudyhouse
• predictingtheeffectivenessofproposedretrofitsforspecifichousesusingthermalperformancesimulations(theoreticalmodelling)
• measuringtheactualtemperature,airleakageandenergyuseineachhousebeforeandafterreplacingappliances,retrofittingandeducatingthehousehold
• determiningtheeffectivenessofbuildingenveloperetrofitsandhouseholdappliancereplacement
• comparingthepredictedresultswiththeactualresults.
Overall,thecasestudiesshowthattheOutreachEnergyandWaterEfficiencyProgramisassistinglow-incomehouseholdstoimprovetheenergyefficiencyoftheirhomes,reducetheirenergyconsumption,reducetheirenergybillsandcontributetoreducinggreenhousegasemissions.
Comparisonofwinterenergybillsfrom2011and2012showsthat9outof11casestudyhomesreducedtheirenergyconsumptionandsavedmoneyontheirbillsasaresultofparticipatingintheOutreachProgram.
Keyresultsrecordedacrossallcasestudyhomeswere:
• anaverage22%reductioninenergyuseinthewinterquartercomparedwiththepreviousyear,madeupof
– 33%reductioninelectricityconsumptioninthewinterquartercomparedwiththepreviousyear
– 5.9%reductioningasconsumptioninthewinterquartercomparedwiththepreviousyear
• anaverage$270.60netdollarsavingperhouseholdinthewinterquarter
• atotalreductionof18.44tonnesofcarbondioxideequivalent(CO2-e)inthewinterquarter.
Oftheeightcasestudyhomesthatunderwentthermalmodelling,allincreasedtheirenergystarratingafterretrofitting.
Whenconsideringcost-effectiveness,draughtsealingwasconsistentlythemosteffectiveretrofitmeasure.Insulationandheavydrapeswithpelmetsalsosignificantlyreducedenergyuseandincreasedcomfortincasestudyhomes.
Datafromfourcasestudyhomesshowedthatreplacingold,inefficientrefrigeratorswithnewmodelscanhalvetheenergyusedforrefrigeration.
Theprojectalsohighlightstheimportanceofbehaviourinthecontextofenergyreductions.
RefertoSection4‘Findingsandrecommendations’formoreinformation.
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1 Background
1.1 The Outreach Energy and Water Efficiency ProgramTheOutreachEnergyandWaterEfficiencyProgramassistslow-incomehouseholdsintheACTtoimprovetheenergyandwaterefficiencyoftheirhomes,reducetheirenergyandwaterconsumption,reducetheirenergyandwaterbills,andcontributetoreducinggreenhousegasemissions.TheprogramhasbeendevelopedbytheACTEnvironmentandSustainableDevelopmentDirectoratewithabudgetof$7.8millionoverfouryearstoJuly2015.
Theprogramprovideseligiblelow-incomehouseholdswithsomeorallofthefollowingassistance:
• ahomeenergyefficiencyassessmentandeducation
• newenergy-efficientandwater-efficientappliancestoreplaceold,inefficientappliances
• aretrofittoimprovetheenergyefficiencyandwaterefficiencyofhouseholds.
TheOutreachProgramisdeliveredbythefollowingcommunitywelfareorganisations:
• BelconnenCommunityService
• Communities@Work
• NorthsideCommunityService
• SocietyofStVincentdePaul
• YWCAofCanberra.
TheseorganisationsimplementtheprogramthroughtheirexistingclientsandobtainclientreferralsfromnetworkswithinthecommunityservicessectoroftheACT.Eachorganisationhasbeenprovidedwithfundingtodelivertheprogram,includingfundingforanEnergyEfficiencyOfficerineachorganisation.TheroleoftheEnergyEfficiencyOfficeristoidentifyeligiblehouseholdsthatwouldbenefitfromenergy-efficientandwater-efficientappliances,andreferthemforahomeenergyefficiencyassessment,retrofitandeducationsessiondeliveredbyapanelofserviceprovidersfundeddirectlybytheACTGovernment.EnergyEfficiencyOfficerscanalsoreferclientstoHousingACTfordraughtsealingandceilinginsulationtop-ups.
1.2 Project aimsTheaimoftheprojectwastocollectandanalysedatatodeterminewhethertheOutreachProgramisimprovinghouseholdenergyefficiency,andtoinformandimprovepolicyandprogramimplementation.Theprojectincluded:
• analysingthethermalperformanceofthebuildingenvelopeforeachcasestudyhouse
• predictingtheeffectivenessofproposedretrofitsforspecifichousesusingthermalperformancesimulations(theoreticalmodelling)
• measuringtheactualtemperature,airleakageandenergyuseineachhousebeforeandafterreplacingappliances,retrofittingandeducatingtheclient
• determiningtheeffectivenessofbuildingenveloperetrofitsandhouseholdappliancereplacement
• comparingthepredictedresultswiththeactualresults.
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2 Methodology
BetweenMarchandSeptember2012,Scinergyconducteddiagnosticassessmentsandcasestudyanalysison11low-incomehouseholdsparticipatingintheOutreachEnergyandWaterEfficiencyProgramusingan‘assessment–education–retrofit’process.
2.1 Recruitment of case study participantsTobeeligibleforinclusionintheOutreachProgramandthecasestudies,participantshadtobe:
• ACTresidents
• experiencingfinancialhardship
• earninglessthanthemaximumincomelimitasdefinedintheOutreachProgramspecifications.
Participationmayassistinreducingfinancialhardshipassociatedwithhighenergyorwaterconsumptioncosts.
Outreachparticipantswereaskedbythecommunityorganisationsiftheywouldliketotakepartinthecasestudies.Participationinthecasestudieswasentirelyoptional.
ThehousesandclientsselectedwerenewparticipantsintheOutreachProgram,hadenergyusagedataavailableforatleasttheprevious12months,andhadpotentialforavarietyofdifferentretrofitandeducationmeasures.
2.2 ToolsThemethodologywasbasedonthewell-establishedtheorythataninsulatedandairtightenvelopeisthekeytoanenergy-efficientandcomfortablebuilding.Usingvarioustechnologies,datawerecollectedtoassesshowwelleachbuildingwasperforming,prioritiseimprovements,andmeasuretheeffectofchangesonenergyuseandcomfort.Toolsincluded:
• householdelectricity-usemonitors
• applianceelectricity-usemonitors
• temperaturedataloggers
• fandepressurisationtoquantifyandlocateairleakage(seeBox1)
• thermographicinspectionofthebuildingenvelopetolocateinsulationgapsandairleaks
• thermalperformancesimulationofthebuildingtopredictheatingandcoolingloads.ThermalperformancewasmodelledusingBERSPro4.2software(whichisaccreditedundertheAustralianGovernment’sNationwideHouseEnergyRatingScheme[NatHERS])toshowthedifferencebetweenthethermalstartingpoint(initialstarrating)andendpoint(starratingafterretrofitting)ofthecasestudyhouses(seeTable2).
Anecdotalinformationwasalsocollectedatsitevisits.
2.3 Data collection timelineDatawerecollectedoverapproximatelyeightweekstomeasure:
• improvedefficiencyofreplacedappliances
• baselineelectricityconsumptionandtemperatureprofile
• energyconsumptionandtemperaturechangeduetoeducation
• energyconsumptionandtemperaturechangeduetoretrofitting
• qualitativefeedbackandinsightsintobehaviouralchangefromclients.
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Box 1 Measuring air leakageAirleakageistheuncontrolledmovementofairintoandoutofabuilding(infiltration)thatisnotfortheplannedpurposeofexhaustingstaleairorbringinginfreshair(ventilation).Itisdrivenbythreemainforces:
• wind,whichexertsconstantlychangingpressuresonbuildings(highonthewindwardsideandlowontheleewardside,roughly150–1500pascals[Pa]differences)
• thestackeffect,whererisingwarmaircausespressuredifferenceswithinbuildings(lowerpressuresatthetop,higherpressuresnearthefloor,around5–10Padifferences)
• mechanicalheatingandventilationsystems,whichcreatepressuredifferenceswithinbuildingsastheyheat,coolandmoveair(5–10Padifferences).
Airleakagecanaccountfor30%ormoreofabuilding’sheatingandcoolingcosts,asocontrollingairleakageisthemosteffectivewaytoachievedirectenergysavings.InCanberra,typicalairleakageratesareequaltotwocompleteairchangesperhour,whichrepresentsasubstantialamountofenergyandmoney,especiallyinwinter.Uncontrolledairleakagealsocompromisestheeffectivenessofother,moreexpensive,energyefficiencymeasuressuchasnewheatingsystems,windowdressinganddoubleglazing.
Thebestwaytomeasureairleakageistouseablowerdoorandthermalcamera.Theblowerdoorincludesfourcomponents:acalibratedfan,anexpandabledoor-panelsystem,asensitivegaugetomeasurefanflowandbuildingpressure,andtailoredcomputersoftware.Thefanissealedintoanexteriordoorwaywiththedoor-panelsystemandthenusedtodrawairoutofthebuilding,creatingapressuredifferencebetweeninsideandoutside.Thispressuredifferencecausesairfromoutside,athigherpressure,tomoveintothebuildingthroughallthegapsinthebuildingenvelope.Thetighterthebuildingenvelope(fewergapsandcracks),thelessfanspeedisneededtocreateachangeinbuildingpressure.Thepressuregaugeandcomputerareusedtoregulateandrecordtheairflowandpressuredifferences.
Thethermalcameraisusedtolocatetheairleaks:aslongastheairbeingdrawninthroughtheleaksiswarmerorcoolerthantheinsideofthehouse,theareasurroundingtheleakwillchangetemperatureandshowuponthethermalimage.Evenifthereislittletemperaturedifferencebetweeninsideandoutside,aninfra-redscancanstillbeeffective,becausesubfloorspacesaregenerallycooler,androofspacesgenerallywarmer,thantheexternalairtemperature.Thistechniqueallowsyoutofindsignificant,andotherwiseundetectable,leakswithouthavingtoentertherooforfloorspace.Athermalcameracanalsoshowwhereinsulationismissingorhasbeenimproperlyinstalled.
aUSDepartmentofEnergy,OfficeofBuildingTechnology,http://apps1.eere.energy.gov/buildings/publications/pdfs/building_america/26446.pdf
DatawerecollectedfromthehouseholdsaccordingtothefollowingtimelineprovidedbytheOutreachProgramtoEnergyEfficiencyOfficersandserviceproviders:
Week 1: Client referral and baseline appliance data
• EnergyEfficiencyOfficeridentifiesclientwhowouldliketoparticipateinthestudy.
• EnergyEfficiencyOfficerconductsahomeenergyassessmentandinstallsapplianceenergymonitoronappliance(s)tobereplaced.
Week 2: Appliance replacement and installation of energy and temperature monitors
• EnergyEfficiencyOfficerrecordspreviousweek’senergyuseofoldapplianceandfitsenergymonitortonewappliance.
• Scinergyinstallstemperaturedataloggers(twointernal,oneexternal).
• Scinergy/electricianinstallshouseholdelectricity-usemonitor.
• Serviceproviderconductsacomprehensivehomeenergyassessmentandeducationsession,andprioritisesenergyefficiencyimprovementstodetermineretrofitmeasures.
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After the Week 2 visit: Thermal performance simulation
• Scinergyassessesthepotentialthermalperformance(predictedheatingandcoolingloadsandstarrating)usingsimulationsoftware.
Week 4: Building envelope testing #1 and education
• Scinergyretrievesapplianceenergymonitorfromnewapplianceandcollectsdata.
• Scinergyconductsairleakagetestingviafandepressurisationandthermographicinspectionofbuildingenvelope.
• Serviceprovidercarriesouteducationalcomponentofprogram,introducesclienttohouseholdenergymonitorandidentifiespotentialenergy-savingbehaviouralchanges.
Week 6: Retrofit
• Serviceprovideroverseesretrofitandinstallationofcurtains(ifrequired).
• Serviceprovidercarriesoutdraught-proofing.
Week 8: Building envelope testing #2 and data collection
• Scinergyretrievestemperaturedataloggersandcollectsresults.
• Scinergydownloadsdatafromhouseholdenergymonitor(monitorleftwithclient).
• Scinergyconductsairleakagetesttomeasureimprovementsachievedthroughretrofit.
After Week 8: Education and quality assurance
• Serviceproviderconductsfinaleducationsession,andchecksthequalityofretrofitandcustomersatisfaction.
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3 Results
Thissectionsummarisestheresultsoftheproject.FulldetailsforindividualcasestudiesarepresentedinAppendixA.
3.1 Characteristics of case study participantsThecharacteristicsoftheparticipatinghouseholdsvariedgreatlyin:
• thesize,age,typeofconstruction,designandorientationofbuildings
• thenumber,ageandeducationlevelofresidents,andtheirinterestinandbehaviourrelatingtoenergyandwaterefficiency.
Sixofthe11householdswereHousingACTresidents,andfivewerehome-owner–occupiers.IntheOutreachProgramasawhole,approximately75%ofparticipantsliveinHousingACTproperties.
Allcasestudyhouseholdshadbetweenoneandthreeresidents,althoughthenumberofpeopleinthehousecouldvaryconsiderablyatanypointintime.Thesevariationsincludednewresidentsmovinginduringthecasestudy,supportstaffpresent(inonehousehold)andhouseholdmembersbeingawayonholidays.
Manyofthecasestudyparticipantsspentconsiderabletimeathomebecauseoftheirfinancialcircumstances.Manywereretired,unemployedorondisabilitysupportpensions.Atleasttwoofthehouseholdshadmemberswithrespiratoryconditionsrelatedtocoldtemperatures,althoughhealthconcernswereself-reported,andmonitoringimprovementsinhealthwasoutsidethescopeofthisproject.
AsummaryofthehouseholdcharacteristicsisprovidedinTable1.
Table 1 Characteristics of case study participants
Case study number
Number of occupants
Type of residence
Financial circumstances
Description
1 3 Owner–occupier
Unemployedfull-timestudent
Motherwithteenagechildren.Twolargelivingareaswithreverse-cycleair-conditioning;centralgasheating.Electricityandgas.
2 1 HousingACT
Disabilitysupportpension
Chroniccardiacandrespiratoryhealthconditions.Gapsarounddoorsandwindows.Participantusesportableelectricresistanceheaterinsteadoftheelectricresistancewallheaterbecauseofitslocation.Electricityonly.
3 1 Owner–occupier
Retired,old-agepension
Participanthaslargewinterheatingbills.In2011,participanthadhealthconcerns,andasecondpersonwaslivinginthehome.Househaselectricheatinginslab.Electricityonly.
4 3 HousingACT
Single-parentpension
Motherofyoungchildrenwithrespiratoryhealthconcerns.Asecondadultmovedinduringthecasestudymonitoring.Extremelycoldhouse,withlimitedsolarheatgainbecauseofhouseorientation,andverydraughty.Electricresistanceheating.Electricityonly.
5 3 Owner–occupier
Disabilitysupportpension
Insulationwasthinandpatchy,andthehousehadpermanentventsineveryroom.Gasheatinginlivingareas.Electricreverse-cyclesystemsinbedrooms.Electricityandgas.
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Case study number
Number of occupants
Type of residence
Financial circumstances
Description
6 2 HousingACT
Singlemotherwithpart-timework
Houseverycoldinwinterandveryhotinsummer.Electricresistancewall-mountedheater.Electricityonly.
7 3 Owner–occupier
Notlisted Housecoldinwinter,hotinsummer.Househadanumberofsignificantairleakagepoints,includingaskylight.Northerlyaspect.Wall-mountedelectricpanelheater.Electricityandgas.
8 3 HousingACT
Notlisted Housecoldinwinterandhotinsummer.Electricheating.Electricityonly.
9 1 HousingACT
Centrelinkpension
Three-storeyapartmentbuiltapproximately50yearsago.Inefficientelectricresistanceheating.Electricityonly.
10 3 HousingACT
Disabilitysupportpension
Threetenantswithdisabilities;1-2staffonsite24hoursperdaywithupto7peoplepresentatanyonetime.Tenantsdonothavedirectcontrolofenergyuseandrelyonstaffmembersforassistance.Gasheating.Electricityandgas.
11 2 Owner–occupier
Disabilitysupportpension
Householdersgetverycoldinwinter.Draughtyhousewithmanypointsofairleakage.Gasheating.Electricityandgas.
3.2 Thermal performance simulationThermalperformanceofthebuildingswasmodelledtoshowthedifferencebetweenthethermalstartingpoint(initialstarrating)andendpoint(starratingafterretrofitting)ofthecasestudyhouses(Table2).Oftheeightcasestudiesthatunderwentthermalmodelling,everyhouseincreaseditsenergystarratingafterretrofitting.
InCanberra’sclimate,a3-starhomeispredictedtorequire387megajoulespersquaremetre(MJ/m2)forheatingandcooling,whichis2.3timesmoreenergypersquaremetrethana6-starhome(165MJ/m2).1
Thedifferencesinmodelledthermalperformanceamonghousesaremainlyduetodifferencesinwindows(orientation,windowdressingsandsizerelativetoroomfloorarea),insulationlevelsandairtightness.Casestudy3,forexample,waswellsealed(withfewceilingpenetrationsorotherairleaks),andhadnorth-facingwindowstothemainlivingareas(allowingpassivesolarheatgainoverwinter),heavydrapestomostwindows,andbothceilingandwallinsulation.Incontrast,casestudies4and5wereextremelyleaky(withpermanentceilingventsineveryroom),andhadlittleopportunityforpassivesolarheatgaintolivingareas,poor-qualitywindowdressings,thinceilinginsulationandnowallinsulation.
TheimportanceofdraughtsealingisoftenunderestimatedinCanberra’sclimate.Thermalperformancemodellingsuggeststhatenergysavingsofapproximately10–20%canbeachievedinsomeofthecasestudyhousesbysealingpermanentceilingpenetrations—arelativelysimpleandinexpensiveretrofitmeasure.Physicalperformancetestingofcasestudyhouses,andstatisticalanalysisofthecorrelationbetweenreductioninairleakageandreductioninenergyuse,suggeststhat,forsomehouses,savingsfromdraughtsealingalonemaybehigherthan20%.
1 SeetheNatHERSat(www.nathers.gov.au)andtheBERSProat(www.solarlogic.com.au/bers-pro)formoreinformationonstarratings.
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Table 2 Star ratings of case study houses 1–8 before and after retrofitting
Case study number Star rating pre-retrofit
Star rating post-retrofit
Retrofit measures
1 3.9 4.5 •Draughtsealing•Pelmetstolivingareas
2 2.8 4.2 •Draughtsealing•Curtainsandpelmetstolivingareas
3 5.9 6.5 •Pelmetstolivingareas•Minordraughtsealing•Fillinggapsinceilinginsulation
4 2.9 4.7 •Draughtsealing•Ceilinginsulationtop-up•Wallinsulation
5 2.8 3.4 •Draughtsealing•Ceilinginsulationtop-up•Curtainsandpelmetstolivingareas
6 4.2 5.2 •Majordraughtsealing•Pelmetstolivingareasandbedrooms
7 3.3 4.9 •Draughtsealing•Curtainsandpelmetstolivingareas
8 2.8 3.4 •Draughtsealing•Curtainsandpelmetstolivingareas
Notes: Casestudies9,10and11werenotincludedinthemodellingbecauseofschedulingconstraints.ThermalperformancewasmodelledusingBERSPro4.2software(whichisaccreditedundertheAustralianGovernment’sNationwideHouseEnergyRatingScheme[NatHERS]).Inregulatorymode,energyefficiencyratingsoftwaredoesnotmodelwindowdressings,andstarratingsareexpressedin0.5increments.Forthepurposeofthisproject,thesimulationsoftwarewasruninnon-regulatorymodetomodeltheimpactofchangestowindowdressings,andratingsareexpressedin0.1incrementstogiveabetterindicationofchanges.FurtherdetailsofactualandpredictedheatingandcoolingloadscanbefoundinAppendixA.
Onlyonecasestudyhousehadwallinsulationinstalledduringthestudy.Thisoccurredverylateintheprocessandappearstohavecoincidedwithasignificantchangeinhouseholdcompositionandenergy-usebehaviour,soitisnotpossibletodrawfirmconclusionsabouttheeffectofwallinsulationfromthisstudy.However,wallinsulationiswellrecognisedasbeingextremelyeffectiveinacool,temperateclimate.TheBuildingCodeofAustraliasetsaminimumstandardofR2.8forexternalwallinsulationsystemsinCanberra’sclimatezone.
ThesoftwareprovidesanestimateofcurrentthermalperformanceusingtheNatHERSstarratingschemeandwasalsousedtopredictwhichbuildingenvelopeimprovementswouldbemosteffectiveforeightofthecasestudyhouseholds.Predictedimprovementsvaried:
• Forcasestudy4,withuninsulatedexternalwalls,installinginsulationwaspredictedtoreduceenergyrequirementsforheatingandcoolingby26%.(Althoughwallinsulationwasnotretrofittedtocasestudies5and8,thermalmodellingsuggesteditwouldresultinreductionsinenergyuseofnearly30%forthesehouses.)
• Forhouseswithlarge,inadequatelyfurnishedwindowstolivingareasthatdonotbenefitfrompassivesolarheatgain(casestudies2and7),installingcurtainsandpelmetswaspredictedtoreduceenergyrequirementsby16–19%.
• Forhouseswithmanyceilingpenetrationsandsubstantialairleakage(casestudies2,4,5,6,7and8),draughtsealingwaspredictedtoreduceenergyrequirementsby9–18%.
• Forhouseswiththinorpatchyceilinginsulation,estimatedtobeequivalenttoR2(casestudies4and5),toppinguptheceilinginsulationtoR4waspredictedtoreduceenergyrequirementsby30–40%.
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3.3 Air leakage rate and locationWhenahouseisdepressurised,airflowsinthroughanycracksorgapsintheinternalbuildingenvelope.Thisaircanoftenbecooler(e.g.airinflowfromsubfloorspacesorshadedwalls)orwarmer(e.g.airfromroofspaces—evenoncoldCanberradays,itdoesnottakemuchsunshinetoheattheairintheroofspacetotemperatureshigherthaninsidethehome).Thisairinflowcancreatetemperaturedifferencesinsidethehomeastheairmovesacrossinternalsurfaces,andcreatedraughts.
Thepresenceofdraughtscanaffectaperson’sperceivedtemperatureofaroom.Draughtscanmakeapersonfeelcoldbyremovingheatfromthebody—whenthedraughtisremoved,theroomcanfeelwarmereventhoughtheactualtemperaturemaybethesame.
Rates of air leakage
Thenumberofairchangesperhouratapressuredifferentialof50pascals(n50)isaninternationallyacceptedstandardforexpressingtherateofairleakageinhomes.Followingtheleadofthe2006UKbuildingstandards,2itissuggestedthathousesintheCanberraclimateshouldaimforann50oflessthan10.Onlytwoofthecasestudyhomesachievedanairleakageratebelow10beforeretrofitting(Image1).Themajorityhadmuchhigherratesofairleakagethatwereseriouslycompromisingtheirenergyefficiencyandcomfort.
Simpledraught-sealingmeasuresreducedtherateofairleakageinninecasestudyhomesbyanaverageof34%.Statisticalmodellingofactualairleakageandenergyconsumptiondatasuggeststhatdraughtsealingaccountsforalmost40%ofenergysavings.TherelationshipbetweenairleakageandenergyuseisdescribedinBox2.
Location of air leaks
Manyoutdatedmeasuresintendedtoimproveventilationandminimisemoisturelevelsandcondensationweremakingthesehousesextremelyleaky,difficulttoheatanduncomfortabletolivein.Airleakageviaceilingpenetrations,suchasunsealedexhaustfans,recessedlights,roofaccessholes,skylightsandpermanentvents,wascommonamongthecasestudyhouses(seeImage2forexamples).Permanentwallvents,openingsinbathroomandlaundrywindows,andgapsbetweenwindowarchitravesandwallswerealsoresponsibleforsignificantleakage.Mostofthesetypesofleakscanbesealedeasilyandcheaply.
PermanentpassiveventilationshouldnotbereliedontocontrolmoisturelevelsormaintainfreshairinCanberrahomes.Instead,activeventilation—mechanicalexhaustfansandthesimpleopeningofwindows—shouldbeusedtoreducemoisturebuild-upintheareaswhereitisgenerated.
Temperaturedifferencescausedbyairleakscanbevisualisedusinganinfra-red,orthermal,camera.Thermalimagescanshowthefingersofblue(createdbycoolerair)ororange(createdbywarmerair)thatoccurnexttoairleaks(Image2).Thesetypesofimagesareusedtohelplocateanddemonstrateairleaks,buttheydonotmeasuretherateofairleakageinparticularlocations
Image 1 Air leakage rates in case study homes before and after draught-sealing Note: Casestudies3and9werenotretestedforairleakageafterdraughtsealingbecausetheywerealreadybelowthetargetlevelof10airchangesperhourat50Pa,andfundswerebetterspentonhomesthatwerefurtherfromthistarget.
2 AirTightnessTestingandMeasurementAssociation,Technical standard L1: measuring air permeability of building envelopes (dwellings),AirTightnessTestingandMeasurementAssociation,Northampton,UK,2010.
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Box 2 The relationship between air leakage and energy useScinergy’sexperienceisthatthemostsubstantialreductionsinenergyuseinCanberrahomesoftenoccurafterairleakageisreduced.Oftheninecasestudyhomesthatweretestedforairleakagebeforeandafterretrofitting,eightshowedapositiverelationshipbetweenreductionsinairleakageandreductioninenergyuse,asshowninImageA.
Image A Relationship between reductions in air leakage and reductions in energy use for nine case study homes
Image 2 Thermal images showing common sources of air leakage in case study houses
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3.4 Thermographic inspection of insulationThermalimagingshowedthatthewallsofmostcasestudyhouseswereuninsulated.Ceilinginsulation,althoughpresent,appearedtobethinorpatchyinsomeofthehouses.Images3and4showexamplesfromtwocasestudyhouses;seeAppendixAformorethermalimages.
Onamild,sunnymorninginMarch(temperature10°Cminimumto20°Cmaximum),theuninsulatedsouth-eastandsouth-westfacingwallsofthemainbedroomincasestudy4wereatapproximately13°C;thethinly,butevenly,insulatedceilingwasat14.5°C.Thebedroomhadbeenheatedovernightbutwasnotheatedatthetimeoftesting.Thishouseisuncomfortablycoldwithoutactiveheatingbecauseofitsinadequateinsulationandlackofpassivesolarheatgain.(seeimage3)
Nowallinsulationwaspresentincasestudy5(asexpectedinahouseofthisage;image4a).Therockwoolinsulationintheceilingwasthinandunevenlyinstalled,causingsignificantfluctuationinceilingtemperaturethroughoutthehouse.Image5bshowsthethinorabsentinsulationattheedgeoftheroofspace(darkorangeareasindicatetheceilingheatingupasaresultofthesunstrikingthenorth-facingroofarea).Image5balsoshowstheupperpartsoftheuninsulatedwallsheatingupasaresultofthesolarheatgainintheroofspace—thiscancontributetosignificantheatbuild-upinsummer.Image5cindicatesthedifferenceintemperaturebetweentheuninsulatedroofaccessholeandtheadjoiningthinlyinsulatedceiling,illustratingthatevenathinlayerofceilinginsulationmakesasignificantdifferencetotherateofheattransfer.
Gapsinceilinginsulationofonly5%equatetoa50%reductionineffectiveness.3Fillinggapsinexistinginsulationcansignificantlyimprovetheenergyefficiencyofahome.
Image 3 Presence and effectiveness of insulation in case study 4
Image 4. Presence and effectiveness of insulation in case study 5
3 USBuildingPerformanceInstitute,Effective R-values for batt insulation,BuildingPerformanceInstitute,Malta,NewYork,2007, www.bpi.org/documents/Yellow_Sheet.pdf.
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3.5 Temperature and energy monitoringTemperatureandhouseholdenergyusevariedwiththedesign,age,construction,orientation,numberofwindowsandtypesofwindowdressingsofthecasestudyhouses;thesize,ageandbehaviourofthehouseholds;andtheheatingneedsandmethodsforeachhouse.Therewerealsodifferencesbetweenthecasestudyhousesinthetimingoftheproject(startdatesrangedfromMarchtoJune),therelativetimingofretrofitmeasuresandstepsinthemethod,andtheavailabilityofdatafrommonitoringdevices.Althoughthesevariationswereexpected,theymadeitdifficulttoassesstheimpactofindividualmeasuressuchaseducationsessionsorinstallationofcurtainsandpelmets.
Possibleexplanationsforapparenttrendsorchangesinindividualcasestudiesarebasedoninformalobservationsmadewhilevisitingthehouses.Thesedataprovideinterestinginsightsintodifferenthouseholds,buttheycannotbereliedontosupportorrejecttheretrofitoreducationalmeasures.Fordataloggingoftemperatureandenergyusedatatoprovidemeaningfulresults,the‘assessment–education–retrofit’processneedstobemuchmorecontrolled,andthedatacollectedneedtobemorecomprehensiveanddetailed.
ThetemperaturesexperiencedinsomehousesarewellbelowthelevelssuggestedbytheWorldHealthOrganizationasnecessarytomaintainhumanhealth.4Retrofitmeasurestoimprovethethermalperformanceofsuchhouseshavethepotentialtoresultinsignificantpositivehealthoutcomes.5
Manyofthecasestudyhouseholdswereexperiencingextremelyuncomfortabletemperatures,butthebetterdesignedandinsulatedhomeshadmorestableinternaltemperatures.Althoughnodefinitiveconclusioncanbemadeontherelativeeffectsofretrofitandeducationmeasureswithoutmorecontrolledtestingofthe‘assessment–education–retrofit’process,thefollowingobservationsontemperaturecanbemade:
• Casestudy2showedareductioninenergyuseafterthedraughtsealingandaslightincreaseininternaltemperatures.Thishouseholdmaybeexperiencingmorecomfortableinternaltemperaturesthanwerepossibleinpreviousyears.
• Casestudy4showedadecreaseinelectricityuseafterdraughtsealing,curtainsandceilinginsulation,andtheinternaltemperaturewasmaintained.Electricityuseincreasedafterafourthpersonmovedintothehome.
• Casestudy5showedareductioninelectricityuseandwarmerinternaltemperaturesaftertheretrofit.However,theenergybillsindicatedthattherewasanincreaseinelectricityforthe2012autumnandwinterperiodscomparedwith2011,andadecreaseingasuse.Thisindicatesthatshort-termobservationsmaynotalwayscorrelatewiththelong-termtrendinenergyuse.
• Casestudy6showednochangeinelectricityuse,butinternaltemperaturesincreasedaftertheretrofit.
• Casestudy9showedareductioninelectricityuse,andinternaltemperaturesweremaintained.Billingdataindicatethatthishouseholdmadethemostsignificantsavingsinelectricityfromthewinterof2011towinter2012.
Casestudy2(Image5onnextpage)wasaone-bedroomunitwithneighbourstothenorth,southandabove.Althoughtheunitwaspoorlyorientedandoverglazed,itbenefitedgreatlyfromtheinsulatingeffectsofneighbouringunits.Energyusedecreasedfollowingdraughtsealing,eventhoughinternaltemperaturesweremaintainedorslightlyincreased.InternaltemperaturesinJunewererelativelystableat14–17°Cinthebedroomand17–20°Cinthelivingarea.
Casestudy4(Image6onnextpage)wasasmallhousewithinadequateinsulationandlackofpassivesolarheatgain.Itwashometotwoinfantswithrespiratoryillnessesandhadtemperaturefluctuationsof5–16°Cinthemainlivingareaand8–18°CinthemainbedroomduringJune.Adramaticreductioninenergyuseoccurredbetweenmid-Mayandmid-Julyaftereducation,draughtsealing,curtaininstallationandceilinginsulationtop-up,buthousetemperaturesweremaintainedatverysimilarlevels.Thiswastheonlycasestudyhousetohavewallinsulationretrofitted.Unfortunately,thiswasnotinstalleduntilAugust,coincidingwithCanberra’scoldestweatherandanotheradultmovingintothehouse.Ratherthantheexpectedreductioninenergyuseorincreaseininternaltemperatures,therewasadramaticincreaseinenergyuse.Theincreaseinenergyusedoesnotappeartohavebeenrelatedtoheatingofthemainlivingareaandsuggestssignificantbehaviouralchangesinenergyuseduetothenewresident.
Casestudy6(Image7)wasa15-year-old,two-bedroomunitwithneighbourstothewest,andnorth-facinglivingareas.Thisunitexperiencedatemperaturerangeof15–20°Cinthelivingareaand12–22°CinthebedroominJune.Roomtemperaturesincreasedandelectricityusedecreasedslightlyafterdraughtsealingandeducation.
4 WorldHealthOrganization,Health impact of low indoor temperatures,reportofaWHOmeeting,Copenhagen,11–14November1985,WorldHealthOrganizationRegionalOfficeforEurope,Copenhagen,1987.
5 GGreenandJGilbertson,Warm front, better health: health impact evaluation of the Warm Front Scheme,CentreforRegionalEconomicandSocialResearch,SheffieldHallamUniversity,UK,2008.
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Images5–7showhourlytemperatures(internalandexternal)inrelationtodailyelectricityuseinthreeofthecasestudyhomes,annotatedwiththetimeofsignificantevents.
• The red lineplotstheelectricityusage,whiletheotherlinesshowtheinternalandexternaltemperatures.
• The horizontal axisisthetimelineofeventsanddailymonitoring.
• The vertical axis plotsbothtemperatureandkilowatthours.
ImagesforotherhouseholdscanbefoundinAppendixA.
Image 5. Electricity use and temperature data in case study 2
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Image 6. Electricity use and temperature data in case study 4
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Image 7 Electricity use and temperature data in case study 6Te
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3.6 Appliance replacement
RefrigeratorsAllfourrefrigeratorsthatwerereplacedweretwo-doorappliances(fridge–freezercombination).Theoldrefrigeratorsincasestudies2and3weresmall–mediumsizedandmadebefore1996.Casestudy7hadasmall–mediumsizedrefrigeratormadein2006,andcasestudy8hadalarge(520litre)refrigeratorofunknownage.Allofthesewerereplacedwithnewrefrigerators.
Electricity-usemonitorsshowedthatnewrefrigeratorsusedanaverageof54%lesselectricitythanoldrefrigerators(Image8).Dataareonlyavailablefromfourhouseholdsbecausesomeofthecasestudyclientshadtheirrefrigeratorsreplacedbeforetheprojectstarted.Interestingly,thereplacementrefrigeratorwasthesamemodelincasestudies3and7.Thedifferenceinconsumptionbetweenthetwonewapplianceshighlightsthechallengeofcollectingdataatdifferenttimesofyear,andtheeffectofotherfactorsonenergyconsumption,suchashouseholdcomposition,behaviour,andpositioningandmaintenanceoftheappliance.
Image 8. Average daily energy use of old refrigerators and new replacement refrigerators
20 OutreachEnergyandWaterEfficiencyProgram-Casestudyreport
Washing machinesTheamountandqualityofthedataavailableregardingwashingmachinereplacementwerelow.Onlyafewcasestudyclientshadtheirwashingmachinesreplaced,anddatacouldonlybecollectedfromthreehouseholds.Twohouseholdsusedverylittleenergyforwashingbecausetheclientsonlyoperatedthemachines2–3timeseachweek.Inonecase,thenewwashingmachineusedmoreenergyperweekthantheoldoneduringtheperiodofmonitoring,butthiscouldhavebeenbecausetheclientwashedthreeloadsratherthantwothatweek.Inanotherunusualhouseholdwithveryhighwashinganddryingrequirements,energyuseinthelaundrycomprisedamuchhigherproportionofoverallenergyuse.
3.7 Household energy billsComparisonofenergybillsfrom2011and2012showsthatenergyconsumptionacrossthecasestudyhomesdecreasedbyanaverageof13%intheautumnquarterand22%inthewinterquarter(Table3).
Mostcasestudyhousessavedenergycomparedwiththepreviousyear,eventhoughthewinterof2012wasthecoolestwinterfornight-timetemperaturessince1997,withtheminimumovernighttemperatureaveraging–0.3°C.6 BecausethecasestudieswereconductedwithoutacontrolgroupthatcouldhelpassesstheaverageenergyuseofCanberrahouseholds,itisdifficulttodeterminetherelativeenergysavingsmadeinthecasestudiescomparedwithacontrol,orwhetherthiswasaffectedbythedifferenttemperatures.
Thequarterlybillingperiodvariedbyuptotwomonthsbetweencasestudyhouses,soforsomehousesthebillencompassedcoldermonths.Forexample,someclientsreceivedautumnbillsinJunefortheMarch–Maybillingperiod,andothersinAugustfortheMay–Julybillingperiod.Billingperiodsbeginninginautumnaredescribedastheautumnquarter;billingperiodsbeginninginwinteraredescribedasthewinterquarter.
Table 3. Energy, greenhouse gas and cost savings for all case studies
Total energy saving (kWh)
Total CO2-e saving (kg)a
Total cost savingb
Average energy saving (%)
Average cost saving
Autumn 8017 7701.32 1055.04 13 $95.91
Winter 19054 18444.56 2976.63 22 $270.60
Autumn=billingperiodsbeginninginMarch–May;winter=billingperiodsbeginninginJune–Augusta Scope2+Scope3emissionfactorforelectricityis1.06kgCO2-e/kWh(source:AustralianGovernmentDepartmentofClimateChange
andEnergyEfficiency,National Greenhouse Gas Accounts factors,July2012).b Costsavingsforgasusagecalculatedusing2.113centspermegajoule
ElectricityElectricitybillsshowedanaverage25%reductioninelectricityconsumptionduringtheautumnquarterandanaverage33%reductioninthewinterquarter,comparedwiththepreviousyear’sbills(Table4).Inmostcases,retrofittingandeducationsessionswereconductedduringtheautumnquarter,sotheimpactoftheprogramonenergyusewassmallerduringtheautumnperiodformosthomes.
Intheautumnperiod,9ofthe11householdsreducedtheirelectricityusecomparedwiththepreviousyear(Image9).
Inthewinterperiod,8ofthe11householdsreducedtheirelectricityusecomparedwiththepreviousyear(Image10).
Table 4 Electricity and greenhouse gas savings for all case studies
Total electricity saving (kWh) Total CO2-e saving (kg)a Average energy saving (%)
Autumn 7107 7533.34 25
Winter 17052 18074.99 33
Autumn=billingperiodsbeginninginMarch–May;winter=billingperiodsbeginninginJune–Augusta Scope2+Scope3emissionfactorforelectricityis1.06kgCO2-e/kWh(source:AustralianGovernmentDepartmentofClimateChange
andEnergyEfficiency,National Greenhouse Gas Accounts factors,July2012).
6 BureauofMeteorology,Canberra in winter 2012: mild days and cold nights for Canberra,BureauofMeteorology,Melbourne,2012.Availableatwww.bom.gov.au/climate/current/season/act/archive/201208.summary.shtml(accessed21March2012).
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Image 9 Electricity use during the 2012 autumn quarter compared with the same billing period in 2011
Image 10. Electricity use during the 2012 winter quarter compared with the same billing period in 2011
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GasFiveofthecasestudyhouseshadgasconnected.Gasconsumptiondatashowedanaverage2.6%reductionintheautumnquarter(Image11)andanaverage5.9%reductioninthewinterquarter(Image12).Foreaseofcomparisonwithelectricitydata,gasconsumptionwasconvertedfromMJperdaytokWhperday(Table5).
Table 5. Gas and greenhouse gas savings for all case studies
Total gas saving (kWh) Total CO2-e saving (kg)a Average energy saving (%)Autumn 910 168.16 2.6Winter 2002 369.95 5.9Autumn=billingperiodsbeginninginMarch–May;winter=billingperiodsbeginninginJune–Augusta Costsavingsforgasusagecalculatedusing2.113centspermegajoule
Image 11. Gas use during the 2012 autumn quarter compared with the same billing period in 2011
Image 12. Gas use during the 2012 winter quarter compared with the same billing period in 2011
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3.8 Cost and greenhouse gas savingsComparisonofenergybillsfrom2011and2012showsthattheaveragenetdollarsavingperhouseholdwas$95.91intheautumnquarterof2012and$270.44inthewinterquarterof2012.Tenof11casestudiesshowedcostsavingsintheirbillforwinter2012,and9of11casestudiesshowedcostsavingsintheirbillforautumn2012,comparedwiththeirenergyusageatthesametimethepreviousyear(Image13).Duringthisperiod,theelectricitytariffincreasedbyanaverageof3centsperkWh.
Atotalreductionof7.7tonnesofcarbondioxideequivalent(CO2-e)wasachievedintheautumnquarterand18.44tonnesofCO2-einthewinterquarterof2012.Nineof11casestudiesreducedgreenhousegasemissionsforwinterandautumn2012comparedwiththesametimethepreviousyear(Image14).
Image 13 Cost savings per quarter in 2012, compared with 2011
Image 14. Carbon dioxide equivalent (CO2-e) savings per quarter in 2012, compared with 2011
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3.9 Household composition and behaviourHouseholdcompositionandbehaviourcanplayasignificantroleinhowenergyisusedwithinahome.Thisishighlightedbythevarietyofcasestudyhouseholds,thenumberofresidentsandtheenergyrequirementoftheresidents.Theamountofenergyusedisalsoaffectedbyresidents’health,suchasrespiratoryconditionsorhealthmanagementappliances.
Thecasestudyhouseholdsrangefromsingle-occupanthouseholdstogroupsofthreeormore.Severalhouseholdshavepeoplewhospendlargeamountsoftimeathomeduringtheday,includingretirees,familieswithsmallchildrenandpeoplewithdisabilities.Thesehouseholdsarelikelytohavehigherheatingloadsthanhouseholdsthatspendmostofthedayawayfromthehome.
Casestudy10isanatypicalhouseholdwiththreeresidentswhohavemoderatetoseveredisabilitiesandatleastonestaffmemberpresentinthehousehold24hoursperday.Thishouseholdcantypicallyhave4–7peoplepresentatanyonetime,andtheenergyuseisnotentirelycontrolledbytheresidents.
Table6showsthedifferencesbetweenthereductioninenergyusedforheatingandcoolingpredictedbythemodellingandtheactualchangeinenergyuseinthehouseholds.Theactualchangeinenergyusealsoincludesenergyusedforappliances,lighting,hotwaterheating,andsoon.
Table 6. Predicted vs actual change in energy use in case studies 1–8 using thermal modelling
Case study number
Predicted reduction in energy for heating and cooling by energy efficiency rating modelling (%)
Actual reduction in overall household energy use between winter 2011 and
winter 2012 (%)1 17 222 36 223 18 734 41 425 21 236 23 357 28 28 16 13
Note: Casestudies9,10and11werenotincludedinthemodellingbecauseofschedulingconstraints.
Differencesbetweenpredictedenergyreductionfromthermalmodellingandactualenergyreduction(Table6)couldbeexplainedbyresidents’behaviour.Caseswheretheactualenergyreductionwaslessthanthepredictedreduction(casestudies2,7and8)couldbeexplainedbyresidentsenjoyingmorecomfortableinternaltemperaturesthantheyhadpreviouslyexperienced,ratherthanmaintaininglowertemperaturesandreducingtheirbills.
Casestudies1,3,4,5and6savedmoreenergythanthesoftwarepredicted.Thiscouldbeduetochangesinbehaviourandtheuseoflighting,hotwaterandotherappliances.Casestudy3hadthemostsignificantreduction,mostlyduetotheresidentrestrictingtheiruseofthein-slabheating,whichhadbeenusedfortheentirehousein2011,toasmallerareain2012.Thishouseholdalsohadfewerpeopleinthehomebetweenwinter2011andwinter2012.
Casestudy4initiallyhadalargereductioninenergyuse,butduringthecasestudyperiodasecondadultmovedintothehome,andtheenergyusechangeddramatically(seeImage6).Thechangeinenergyusedidnotappeartobeassociatedwithheatingofthemainlivingareasbecausetheinternaltemperaturesremainedconstant.Thishighlightstheimportanceofbehaviourinthecontextofenergyreductions.
RefertoAppendixAformoredetailsabouthouseholdcomposition,healthandbehaviourthatmightaffectenergyuse.
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3.10 Type of heating systemThetypeofheatingsystemcansignificantlyaffectenergyuse.Forexample,inefficientelectricheatingsystemsareoftenfoundinhouseholdsparticipatingintheOutreachProgram.Thesesystemscanbeexpensivetooperateandhaveminimalbenefits,especiallyiftheheatersarefixedelectricsystemsthathavebeeninappropriatelypositioned.Thisisparticularlyevidentincasestudy9,whichisasingle-occupant,three-storeyhomewithinefficientelectricresistanceheating.Thishouseholdhadthehighestenergyconsumptioninthewinterperiodofalltheparticipatingcasestudies,andelectricityuseincreasedmorethanfourfoldfromautumntowinter.Theeffectofdifferencesinthetypeofheatingsystemisalsoevidentincasestudy3,whichhasinefficientin-slabheating.
3.11 Client responses to energy monitorsScinergywasnotcontractedtoformallycollectoranalysequalitativedata.However,repeatedenthusiasticanecdotalfeedbackwasreceivedfromclientsabouttheenergymonitors.Itseemedthatenergymonitorswerenotonlyusefulasameanstocollectdailyenergy-usedata,butwerealsovaluableeducationaltoolsandmotivatorsofbehaviouralchange.Severalclientsusedthemtomeasuretheenergyuseoftheirappliancesandunderstandhowtheiractionsaffectedenergyuseindetail(sometimesevenbeforetheserviceproviderhadshownthemhowtousethedevice).Thepresenceoftheenergymonitorsseemedtomotivateclientstoreducetheirenergyconsumptionbyobservingandlimitingtheuseofcertainhigh-energyappliancesandbehaviours.Perhapsnotsurprisingly,clientspreferredtousethemonitorsonthe‘cost’setting,whichdisplayedenergyuseindollarsandcentsratherthanwatts.
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4 Findings and recommendations
TheOutreachProgramhadasignificantandmeasurableeffectontheenergyuseofallofthehouseholdsparticipatinginthecasestudies.Importantly,householdenergybillsshowedasubstantialreductioninenergyuseafterretrofittingcomparedwiththepreviousyear,andallhousesincreasedtheirenergyefficiencyrating.Thisalsocorrelatedwithcostsavingsonenergybillsandreducedgreenhousegasemissionsasaresultoftheprogram.
4.1 Thermal performance simulation
Finding
Alleightcasestudyhousesthatunderwentthermalmodellingincreasedtheirenergystarratingafterretrofitting.
Casestudyhomesvariedintheirthermalpotentialasaresultofdifferencesinglazing(orientation,dressingsandsizerelativetoroomfloorarea),insulationlevelsandairtightness.Themosteffectivewaytoreduceenergyuseandincreasecomfortthereforealsovariedamongcasestudyhouses:forsome,simpledraughtsealingwasthemosteffectiveoption,whilewallinsulationwasthebestoptionforothers.Heavydrapesandpelmetsalsosignificantlyreducedenergyuseinsomehouses.Whenconsideringcost-effectiveness,draughtsealingwasconsistentlythebestoption,sometimesbyasmuchas5–10times.
Recommendations
• Eachhouseholdshouldcontinuetobeassessedindividuallytoaccuratelydetermineandprioritisetheretrofitandeducationmeasures.Retrofitmeasuresandeducationsessionsmustcontinuetobetailoredtotheindividualhome,andissuesprioritisedtomaximiseenergy-savingpotentialforthelowestcost.
• Windowdrapereplacementshouldberestrictedtomainlivingareaswherecurrentdrapesareinadequate(unlessotherwisejustified).
• Theuseofcheapandeffectivepelmetoptions(suchascorflutetosealthegapbetweenthetopofthecurtaintrackandwall)shouldbeencouraged.
4.2 Air leakage rate and location
Finding
Mostcasestudyhouseshadhighratesofairleakage,andthemajorityofleakswereviaceilingpenetrations.Simpledraught-sealingmeasuresreducedtherateofairleakageinninecasestudyhomes,byanaverageof34%.Statisticalmodellingofactualairleakageandenergyconsumptiondatasuggeststhatdraughtsealingaccountsforalmost40%ofenergysavings.
Draughtsealinghasprovedtobethemosteffectiveretrofitmeasureforthesecasestudyhomes.Notonlydoesheatedairremaininthehomeforlonger,theclientalsofeelsmuchwarmer.
PermanentpassiveventilationshouldnotbereliedontocontrolmoisturelevelsormaintainfreshairinCanberrahomes.Instead,activeventilation—mechanicalexhaustfansandthesimpleopeningofwindows—shouldbeusedtoreducemoisturebuild-upintheareaswhereitisgenerated.
Recommendations
Draughtsealingshouldcontinuetobeakeyelementofretrofits.Tooptimisethebenefitofdraughtsealing,thefollowingproceduresareabest-practiceguide:
• Draughtsealfromthetopdown.Focusonextractorfansinheatedareas,passivevents,wallventsandventedskylights.
• Remindclientsoftheimportanceofusingextractorfansinthekitchenandbathroomfollowingdraught-sealingmeasurestopreventmoistureaccumulationandcondensation.Extractorfanscanalsobeusedtoventhotairfromahomeinsummer.
• Considerhouseholdbehaviourandpetswhenprioritisingtheretrofit.Thereislittlepointindraught-proofingahomeifexternalandinternaldoorsandwindowsareleftopentoallowventilationandmovementofpets. Discussoptionswiththeclientthatallowpetmovementwhilekeepingdoorsshut.
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4.3 Insulation
Finding
CeilinginsulationiscriticalintheCanberraclimate,andthemajorityofcasestudyhomeshadatleastR2.5insulationinstalled.Afterthislevelofinsulation,thesimulationsoftwareindicatedthatthenextmostcost-effectivemeasuresforCanberrahousesaredraughtsealingandwallinsulation.Mostcasestudyhouseshaduninsulatedwalls,andgapsintheirceilinginsulation.
Recommendations
• Ceilinginsulationshouldbetoppedupwherenecessary.
• Wallinsulationshouldbeconsidered,wherepossible,andparticularlyforhomeswithverypoorthermalperformance.Althoughtherearepotentialelectricalissuesandextracostsinvolved,insomecasesthepredictedbenefitstilloutweighstheup-frontcost.
4.4 Temperature
Finding
Beforeretrofitting,manycasestudyhousesexperiencedextremelyuncomfortabletemperaturesthatmaycompromisethehealthofresidents.
Temperaturemonitoringindicatedanimprovementinthetemperatureinseveralofthecasestudiesafterretrofits;however,temperatureandenergymonitoringwerecomplicatedbyexternalfactors.
Recommendations
• Althoughusefulforshowingtrends,temperaturemonitoringshouldbemoretightlycontrolledtomeasuretheeffectsofindividualmeasuressuchasretrofitsoreducation.
• Asurveyofcomfortlevelsexperiencedbyparticipantsshouldbeincludedinfuturestudies.
4.5 Appliance replacement
Finding
Datafromfourcasestudyhomesshowedthatreplacingold,inefficientrefrigeratorswithnewmodelscanhalvetheenergyusedforrefrigeration.Dataforreplacingwashingmachineswerenotsufficienttoallowanyconclusionstobedrawn.
Recommendations
• Oldrefrigeratorsandfreezersshouldcontinuetobereplaced.
• Furtherresearchshouldbeconductedtodeterminetheenergyandwatersavingsachievedbywashing-machinereplacement.
4.6 Household energy use
Finding
Comparisonofenergybillsfrom2011and2012showsthatenergyconsumptionacrossthecasestudyhomesdecreasedbyanaverageof13%intheautumnquarterand22%inthewinterquarter.Thisdecreaseincludeselectricityandgas.
Comparisonofenergybillsfrom2011and2012showsthatelectricityconsumptionacrossthecasestudyhomesdecreasedbyanaverageof25%intheautumnquarterand33%inthewinterquarter.
Inthefivecasestudyhouseswithgasconnected,gasconsumptiondecreasedbyanaverageof2.6%intheautumnquarterand5.9%inthewinterquarter.However,variationsinbillingperiodsamonghouseholdsmadedirectcomparisonsdifficult.
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Recommendation
• Furthercasestudiesofhouseswithgasconnectionswouldhelptounderstandwhyreductionsinthisformofenergyweremuchlessthanforelectricity.
4.7 Cost and greenhouse gas savings
Finding
Comparisonofenergybillsfrom2011and2012showsthattheaveragenetdollarsavingperhouseholdwas$95.91intheautumnquarterof2012and$270.60inthewinterquarterof2012.
Atotalreductionof7.7tonnesofCO2-ewasachievedintheautumnquarterand18.44tonnesofCO2-einthewinterquarterof2012.
Recommendation
• Greenhousegasemissionsandenergycostsshouldcontinuetobemonitored.
4.8 Household composition and behaviourDifferencesbetweenenergyreductionpredictedbythermalmodellingandactualenergyreductioncouldbeexplainedbyresidents’behaviour.Severalofthecasestudiesvariedsignificantlyfromthepredictedenergyreduction,whichindicatestheinfluenceofbehaviouronenergyreduction.Thisismostnotablydemonstratedbycasestudy3,whichsaved73%comparedwithapredictionof18%.
Recommendations
• Educationshouldcontinuetobeprovidedtoprogramparticipantstomaximiseopportunitiesforenergyreduction.
4.9 Client responses to energy monitors
Finding
Repeatedanecdotalevidencefrommultiplecasestudyhomessuggeststhatenergymonitorsmaybeusedasatooltosupportandmotivatebehaviouralchange.
Recommendation
• Formaltrialsofhouseholdenergymonitorsshouldbeconductedtoassesstheirimpactonclientbehaviour.
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Appendix A Case studies
Case study 1Communitywelfareorganisation:SocietyofStVincentdePaul
Serviceprovider:C&JGroup
Background information from Energy Efficiency Officer
Category Clientwouldbenefitfromanassessment,educationandbasicretrofit,suchascurtains,blindsanddraughtsealing
Household occupants 3
Financial circumstance Unemployed,full-timestudent,financialhardship
Type of residence Owner–occupier
Products to be replaced Washingmachine
Client concerns Overglazedbrick-veneerhousewithacape-codextension/masterbedroomupstairs.Approx.16m2oflivingareaandagrannyflatthatisrentedout.Thehousehasasmall2kWphotovoltaicsystemandflat-panel(twopanels)solarhotwatersystem,boostedbyinstantaneousgas.Ithastwolargeandsegregatedlivingrooms,bothofwhichareheatedandcooledbyanundersizedreverse-cycleair-conditionerinoneoftherooms,inadditiontothecentralgasheating.Thehousehasverylargesouth-facingwindowsandneedsall-rounddraught-proofingandsomeadditionalpropercurtains.Theclientisasinglemotherwithtwochildren,andtwograndchildrenwholivetherepart-time.Sheisveryinterestedinthesubjectmatterandcouldgreatlybenefitfromfurthereducationandretrofit.
Date of referral 12February2012
The house, its timeline of retrofitting activities and thermal performanceExtended,four-bedroom,two-bathroom,brickveneer,concreteslab,150m2.Originalhouseapproximately35yearsold,extensionapproximately20yearsold.
Thepotentialforpassivesolarheatgainishighasaresultofextensiveglazingtothenorthinthelivingroom,loungeroomandbedrooms,allowingthesuntostriketheconcreteslab.However,therearealsosignificantareasofglazingtothesouthinthemainopen-plankitchen/livingarea,whichcompromisethethermalperformanceofthehome.
Theclientalsohassolarpanelsforelectricitygeneration,andasolarhotwatersystemwithaninstantaneousgasboost.
Thethermalperformancesimulationindicatesthatdraughtsealingcouldbeasmuchas10timesmorecost-effectivethancurtainreplacementandpelmetinstallationinreducingtheheatingrequirementsforthishome.
Aerial view ↑North Modelled in BERS4.2 thermal simulation software Orange: kitchen/dining/living; red: living; blue/purple: bedrooms; green: laundry/bathroom; yellow: corridor
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Timeline of testing and retrofitting activities
Date Action
22March Temperatureandenergy-usedataloggersinstalled
12April Airleakageassessmentandthermographicinspectionandeducation
4May Draughtsealing
10May Curtainsandpelmetsinstalled
17May Post-retrofittestandcollectionoftemperatureandenergy-usedata
28May DraftStoppa®overkitchenexhaustfanandinternaldraught-proofing
1June Recessedhalogenlampsinkitchenreplacedwithcompactfluorescentlamps
7June Finalblowerdoortestanddatacollection
Thermal performance simulation (energy efficiency rating) of proposed retrofit measures
Simulation and specifications Star rating
Heating (MJ/m2)
Cooling (MJ/m2)
Total (MJ/m2)
Predicted reduction
(%)
Actual cost ($)
Cost per MJ reduction
($)
Startingconditions:•CeilingsR3;wallsR1.5toextension,R0tooriginal;floorsR0
•Openexhaustfanandthreeventeddown-lightsinkitchen
•Leakyoldwall-mountedair-conditioningunitinlounge
•Curtainsbutnopelmetstowindowsthroughout
3.9 258 32 290
Startingconditionsplus:•Draughtsealing
4.2 233 32 265 9 450 18
Startingconditionsplus:•Curtainsandpelmetstoloungeanddining
4.2 238 32 270 7 4193 209
Completeretrofit:•Sealedexhaustfans•Sealedvents•Draughtsealed•Curtainsandpelmetstoloungeanddining
4.5 210 31 242 17 4643 96
Air leakage resultsVisualinspectionsuggestedthatthehousewouldbeveryleaky,andthiswasconfirmedbyfandepressurisationtesting.Thebuildingenvelopehadmanyobviousleakagepoints,including:
• unsealedexhaustfaninkitchen
• permanentventsinvariouspartsofthehome
• viaplumbingandelectricalpenetrationsbehindkitchenjoinery
• recessedlightinginceiling
environment.act.gov.au 33
• unsealed‘Tastic’inbathroom
• unnecessarypermanentventinbedroomandlivingareas
• arounddoorsandsurroundingarchitrave
• aroundoldwall-mountedheater
• aroundexposedbeamsandsuspendedflooring
• betweenwindowsandgyprock,walljunctionsandroofbeams.
Therateofairleakagewasreducedby18%afterthefollowingdraught-sealingmeasures:
• installingaDraftStoppa®inthekitchen
• sealingunnecessaryceilingvents
• sealingaroundsomearchitravesandwindows
• installingaperspexpanelonthefrontoftheoldwall-mountedheater
• replacinghalogendown-lightswithsealedcompactfluorescentdown-lights.
Result from air leakage testing
Pre-retrofit Post-retrofit Difference
Airchangesperhourat50Pa 21.8 17.82 –18.3%
Effectiveleakageareaat4Pa(equivalentopensquarewindow)
45cmx45cm 40cmx40cm 21cmx21cm
Note: Apressuredifferenceof4Pabetweeninsideandoutsideisclosetothenormalpressuredifferentialexperiencedinthehomeoncold,windyCanberradays.
Air Leakage points
Ceiling vent in bedroom Unsealed exhaust fan in kitchen Leakage between architrave and gyprock
Leakage around air-conditioner Leakage through heating vent
34 OutreachEnergyandWaterEfficiencyProgram-Casestudyreport
InsulationCeilinginsulationwaspresentandmostlyeven;thereweresomeinconsistentareas,mostlyaroundtheextremitiesofthehouse.
Thehousehasexcellentpotentialtousewintersolarheatgainthroughthelargeglazedareasfacingnorth.However,thehousealsohaslargeareasofglazingfacingsouth,whichcompromiseitsabilitytoretainheat.Italsohasadraughtyloftareaatoneendofthehousethatactstoremovemuchoftheaccumulatedheatandnegatesthepassivesolarheatgain.
Inadequate insulation
Inadequate insulation in living area
Solar heat gain through northern windows
Temperature and electricity useThehouseexperiencesseverelycoldtemperaturesinJune,withlivingareasrangingfrom10–22°Candbedrooms 6–15°C.
Datafromthermochronshighlightsthefollowing:
• Littleadditionalheatingisusedinthehomeduringtheevening.Thefamilyareaisoccasionallyheatedbutnotexcessively.
• Atsomepointinthemiddleoftheday,theinternaltemperaturereaches25°Casaresultofthepassivesolarheatgain.However,becauseofglazingonthesouthsideofthehouse,theseroomsalsodropaslowas10°Catnight.
• Theoveralltemperatureremainedconstant,despiteadecreaseinenergyusebytheclient.
• Theunheatednorth-facingbedroom,inwhichcurtainswererarelyopenedbutthewindowwasleftajar,followsexternaltemperaturesveryclosely.
Clientbehaviourplaysalargepartinkeepingthishousewarmandcold.Freshairisflushedthroughthehousethroughouttheday,whichkeepsthehousecool,despiteitshavingexcellentsolaraccessinthelivingandloungeroomsandsomeofthebedrooms.
Theclientreallylikesfreshairand,whilethehouseisnotaswarmasitcouldbeifitwasclosedandallowedtobenefitfromsolarpassiveheatgain,sheisusingnoadditionalheatingduringthedayandthereforenotwastingenergyintheprocess.
environment.act.gov.au 35
Electricity use and temperature data in case study 1
1 A
PRIL
Tem
pera
ture
(0 C)
1 M
AY
1 JU
NE
5 5
10 10
15 15
20 20
25 25
30 30
35 35
0 0
bedroom temperatureexternal temperatureDinner room temperatureElectricity use
Electricity use
Lounge temperature
Leakage test and
education
Draught sealing 1
Draught sealing 2
Replacehalogen lamps
Curtainsand
pelmets
Post retrofit
test
Post retrofit test
Energy billsWhileelectricitydecreased,gasconsumptionincreased.Thiswasforavarietyofreasons:
• Thebrokeninstantaneous-boosthotwatersystemwasdisconnectedforseveralmonthsin2011andthenreconnectedin2012.
• Theclientwasadvisedintheeducationsessiontoboilwaterinakettleonthegasstoveratherthanusinganelectrickettle.Theclientfoundthispracticeunsustainableandtimeconsuming(waitingforthekettletoboil)andhasswitchedbacktotheelectrickettle.
• Themothersaidteenagersweretakinglongerhotshowersthantheyearbefore.
Electricity usage
Energy use 2011 (kWh/day) Energy use 2012 (kWh/day) Difference
Autumn* 30 17 –43%
Winter* 40 22 –45%
Gas usage
Energy use 2011 (kWh/day) Energy use 2012 (kWh/day) Difference
Autumn* 7 13 +85%
Winter* 5 13 +160%
Electricity + gas usage
Energy use 2011 (kWh/day) Energy use 2012 (kWh/day) Difference
Autumn* 37 30 –19%
Winter* 45 35 –22%
*Autumn=billingperiodsbeginninginMarch–May;winter=billingperiodsbeginninginJune–August
36 OutreachEnergyandWaterEfficiencyProgram-Casestudyreport
Predicted versus actual reductions in energy useThermalsimulationsuggestedthatreductionsinenergyuseof17%forheatingandcoolingcouldbeachievedviathedraught-sealingandwindow-dressingmeasuresimplemented.
Actualenergyconsumptiondatafromquarterlybillsdemonstratea22%reductioninoverallhouseholdenergyuse(i.e.notjustheatingandcoolingbutalsoappliances,lighting,hotwaterheating,etc.)betweenwinter2011andwinter2012.Thissuggeststhateducationandassociatedbehaviouralchangecouldaccountfortheremaining5%reductioninenergyconsumption.
Total energy, greenhouse gas and cost savings
Energy saving (kWh) CO2-e saving (kg)a Cost saving ($)b
Autumn* 625 1140.19 112.86
Winter* 903 1594.51 204.95
a Scope2+Scope3emissionfactorforelectricityis1.06kgCO2-e/kWh.Emissionfactorfornaturalgasis51.33kgCO2-e/GJ(source:AustralianGovernmentDepartmentofClimateChangeandEnergyEfficiency,National Greenhouse Gas Accounts factors,July2012).
b Costsavingsforgasusagecalculatedusing2.113centspermegajoule
*Autumn=billingperiodsbeginninginMarch–May;winter=billingperiodsbeginninginJune–August
environment.act.gov.au 37
Case study 2Communitywelfareorganisation:BelconnenCommunityService
Serviceprovider:CoolPlanet
Background information from Energy Efficiency Officer
Category Clientwouldbenefitfromanassessment,educationandbasicretrofit,suchascurtains,blindsanddraughtsealing
Household occupants 1
Financial circumstance Disabilitysupportpension
Type of residence ACTHousing,bottomstorey,one-bedroombrickveneer
Products to be replaced Washingmachineandrefrigerator
Client concerns Theclientlivesaloneinthistownhouse.Hehaschroniccardiacandrespiratoryhealthconditionsandisvisionimpaired.Heisverymindfulofhisenergyuseandusesaveryoldfanheaterratherthanthewall-mountedelectricheater,andhas‘doorsnakes’atsomeofhisdoors.Hehascurtainsthatarenotblock-out,andnopelmets.Therearegapsarounddoorsandwindows.Hisold,inefficientrefrigeratorandwashingmachinewillbereplaced.Theclientiskeentoreducehisbills,hasagreedtotakepartinacasestudyandwillgreatlybenefitfromthisexercise.
Date of referral 23February2012
The house, its timeline of retrofitting activities and thermal performanceThisisasmallone-bedroomunit.
Thethermalperformancesimulationindicatesthatthedraught-sealingmeasuresimplementedmaybealmosttwiceascost-effectiveasthewindowdressingupgradesinreducingoverallenergyrequirementsforheatingandcoolinginthishouse.
Aerial view ↑North Modelled in BERS4.2 thermal simulation software Pink: kitchen/dining; blue: bedroom; green: laundry/ bathroom; yellow: corridor
Timeline of testing and retrofitting activities
Date Action
2April Temperatureandenergy-usedataloggersinstalled
16April Airleakageassessmentandthermographicinspection
20April Education
1May Draught-proofingexternalandinternaldoors
18May Curtainsandpelmetsinstalled
18May Post-retrofittestandcollectionoftemperatureandenergy-usedata
20June Furtherdraught-proofingcavitydoorsliderandwall–ceilingjoins
22June Finalblowerdoortestanddatacollection
38 OutreachEnergyandWaterEfficiencyProgram-Casestudyreport
Thermal performance simulation (energy efficiency rating) of proposed retrofit measures
Simulation and specifications
Star rating
Heating (MJ/m2)
Cooling (MJ/m2)
Total (MJ/m2)
Predicted reduction (%)
Actual cost ($)
Cost per MJ reduction ($)
Startingconditions:•Insulatedbyneighboursabove,tonorthandsouth
•Verydraughty•Curtains,nopelmets
2.8 344 70 414
Startingconditionsplus:•Curtainsandpelmetstoloungeandbedroom
3.4 285 48 334 19 1509 19
Startingconditionsplus:•Draughtsealing
3.3 274 75 349 16 747 11
Completeretrofit:•Draughtsealing•Curtainsandpelmets
4.2 215 52 267 36 2256 15
Air leakage resultsInitialtestingofthebuildingshowedthatitwascomparativelywellsealed.Thebuildingwasconstructedfrombrickandrenderedcement,withfewdoorsandwindows,andhadhighthermalmass.
Thebuildingenvelopehadmanyobviousleakagepoints,including:
• aroundplumbingpenetrationsinbathroom
• betweeninternalbrickandcement-renderedwalls
• betweenbricksandwindowframes,aswellassliding-doorframe
• throughinternal-wallsliding-doorframe
• throughgapswherebrickworkmeetsceiling
• throughunsealedexhaustfaninlaundry
• permanentopeninginbathroomwindow.
Silicon-basedsealantwasusedtofillgapsbetweenrenderedconcreteandbrickwallsinthelivingareasandbathroom,andaroundwindowanddoorframes.Thiswasalsousedaroundplumbingpenetrations.Doorsweresealedwithbrushandtapesealinginthebathroom(whichhadapermanentwindowvent)andthelaundry(whichhadanunsealedexhaustfanasaventfortheclothesdryer),toincreasetheairtightnessoftheconditionedspaceofthebuilding.However,duringtesting,boththesedoorswereleftopen,whichmeansthatthefinalairleakagetestdoesnotcapturethefullpictureoftheretrofittingmeasuresputinplace.
Result from air leakage testing
Pre-retrofit Post-retrofit Difference
Airchangesperhourat50Pa 13.3 11.8 –11%
Effectiveleakageareaat4Pa(equivalentopensquarewindow)
25cmx25cm 23cmx23cm 11cmx11cm
Note: Apressuredifferenceof4Pabetweeninsideandoutsideisclosetothenormalpressuredifferentialexperiencedinthehomeoncold,windyCanberradays.
environment.act.gov.au 39
Air Leakage points
Leakage between window frame and internal brickwork
Leakage at junction of wall and ceiling in bathroom
Leakage between internal timber cladding, brickwork and ceiling
InsulationAsaground-floorunitinatwo-storeyapartmentcomplex,thisresidencebenefitedfrominsulationbyneighbourstothenorthandsouthandabove.Theexternal,uninsulatedandhighlyglazedeasternandwesternwallswerebyfarthecoolestpartsofthehouse.
Refrigerator replacement
Energy usage results for old and new refrigerators
Energy use (kWh/day) Energy use (kWh/year) CO2-e (kg/year)a Difference
Old 1.47 537 569
New 0.81 295 313 –45%
a Scope2+Scope3emissionfactorforelectricityis1.06kgCO2-e/kWh(source:AustralianGovernmentDepartmentofClimateChangeandEnergyEfficiency,National Greenhouse Gas Accounts factors,July2012).
Temperature and electricity use
Electricity use and temperature data in case study 2
Tem
pera
ture
(0 C)
1 M
AY
1 JU
NE
5 5
10 10
15 15
20 20
25 25
30 30
0 0
Bedroom temperature External temperature Electricity use
Electricity use
Leakagetest and
education
Post-
test
Tem
pera
ture
(0 C)
5 5
10 10
15 15
20 20
25 25
30 30
35 35
0 0
Electricity use
Draught sealing 2
Draught sealing 1
Living room temperature
Curtainsand
pelmets
40 OutreachEnergyandWaterEfficiencyProgram-Casestudyreport
Energy bills
Electricity usage
Energy use 2011 (kWh/day) Energy use 2012 (kWh/day) Difference
Autumn* 15 11 –22.1%
Winter* 27 21 –22.1%
Predicted versus actual reductions in energy useThermalsimulationsuggestedthatreductionsinenergyuseof36%forheatingandcoolingcouldbeachievedusingthedraught-sealingandwindow-dressingmeasuresimplemented.
Actualenergyconsumptiondatafromquarterlybillsdemonstrateasmaller,butstillverysignificant,22%reductioninoverallhouseholdenergyuse(i.e.notjustheatingandcoolingbutalsoappliances,lighting,hotwaterheating,etc.)betweenwinter2011andwinter2012.
Theclientmaybeusingtheremainingpotentialreductionsinenergyuse(suggestedbythethermalmodelling)tomaintainmuchmorecomfortabletemperaturesthanpossibleinpreviousyears.Ratherthantakingallthebenefitintheformofreducedbills,thisclientisprobablyenjoyingthebenefitofincreasedcomfort.
Total energy, greenhouse gas and cost savings
Energy saving (kWh) CO2-e saving (kg)a Cost saving ($)b
Autumn* 294 312.08 44.60
Winter* 550 583.53 94.71
a Scope2+Scope3emissionfactorforelectricityis1.06kgCO2-e/kWh(source:AustralianGovernmentDepartmentofClimateChangeandEnergyEfficiency,National Greenhouse Gas Accounts factors,July2012).
b Costsavingsforelectricitycalculatedusing15.15(autumn)and17.21(winter)centsperkilowatthour
*Autumn=billingperiodsbeginninginMarch–May;winter=billingperiodsbeginninginJune–August
environment.act.gov.au 41
Case study 3Communitywelfareorganisation:BelconnenCommunityService
Serviceprovider:CoolPlanet
Background information from Energy Efficiency Officer
Category Clientwouldbenefitfromanassessment,educationandbasicretrofit,suchascurtains,blindsanddraughtsealing
Household occupants 1
Financial circumstance Retired65+man,onagedpension.Hasoldinefficientwhitegoodsandlargeheatingbills.Difficultypayingbills,unabletoaffordtoreplacewhitegoods.
Type of residence Homeowner,singlestorey,brickveneer,southfacing,kitchenanddiningareanorthfacing
Products to be replaced Refrigerator,freezerandwashingmachine
Draught sealing required?
Feelshishomeisprettytightlysealed
Client concerns Theclienthaslivedinthisfour-bedroomhomeforabout15years.Hetriestoavoidusingunderfloorheatingasmuchaspossible,becauseelectricitybillspikesinwinter.Theclienthasnetandlightblock-outcurtainsinmostoftherooms,butnopelmets.Theclientisconsciousofenergyefficiencyandiskeentoseehowmuchhecansavemoneyandimprovethecomfortofhishome,particularlyinwinter.Heisveryopentobeingpartofthecasestudy.
Date of referral 4April2012
The house, its timeline of retrofitting activities and thermal performanceThethermalperformancesimulationindicatesthatthishousewasalreadyperformingverywellthermallyandthatfundswouldhavebeenbetterdirectedtootherhomesthatperformedlesswell.Althoughthehousewasnotveryleakycomparedwithothercasestudyhomes,draughtsealingwasstillthemostcost-effectiveretrofitmeasure.
Aerial view ↑North Modelled in BERS4.2 thermal simulation software Pink: kitchen/dining/living area; brown: secondary living area; blue/purple: bedrooms; green: laundry/bathroom
Timeline of testing and retrofitting activities
Date Action18April Temperatureandenergy-usedataloggersinstalled20May Airleakageassessmentandthermographicinspection19May Education10June Draught-proofingexternalandinternaldoors22June Curtainsandpelmetsinstalled
42 OutreachEnergyandWaterEfficiencyProgram-Casestudyreport
Thermal performance simulation (energy efficiency rating) of proposed retrofit measures
Simulation and specifications Star rating
Heating (MJ/m2)
Cooling (MJ/m2)
Total (MJ/m2)
Predicted reduction
(%)
Actual cost ($)
Cost per MJ reduction
($)
Startingconditions:•CeilingsR3—somegaps•WallsR1.5•Openexhaustfansinbathrooms,otherwisewellsealed
Goodcurtains,nopelmets
5.9 160 9 170
Startingconditionsplus:•Draughtsealing
6.2 146 9 155 9 423 28
Startingconditionsplus:•Ceilinginsulationgapsfilled
6.0 157 8 165 3 220 44
Startingconditionsplus:•Pelmetstolivingareas
6.2 149 9 157 8 1100 85
Completeretrofit:•Pelmetstolivingareas•Blindtokitchen•Ceilinginsulationgapsfilled•Sealedexhaustfan•Sealedexternaldoors
6.5 132 8 140 18 1743 58
Air leakage results
Result from air leakage testing
Pre-retrofit Post-retrofit Difference
Airchangesperhourat50Pa 7.72 – –
Notes: Casestudy3wasnotretestedforairleakageafterdraughtsealingbecauseitwasalreadybelowthetargetlevelof10airchangesperhourat50Pa,andfundswerebetterspentonhomesthatwerefurtherfromthistarget.
Refrigerator replacement
Energy usage results for old and new refrigerators
Energy use (kWh/day) Energy use (kWh/year) CO2-e (kg/year)a Difference
Old 2.1 766 812
New 0.92 329 349 –57%
a Scope2+Scope3emissionfactorforelectricityis1.06kgCO2-e/kWh(source:AustralianGovernmentDepartmentofClimateChangeandEnergyEfficiency,National Greenhouse Gas Accounts factors,July2012).
environment.act.gov.au 43
Temperature and electricity useEnergyconsumptionclearlydroppedfollowingtheeducationsessionandexplanationoftheenergy-usemonitor.
Electricity use and temperature data in case study 3
Educationre in-slabheating
Leakagetest
Tem
pera
ture
(0 C)
Electricity use (kWh)
50 50
40 40
30 30
20 20
10 10
0 0
1 M
AY
1 JU
NE
External temperatureElectricity use
Electricity use
Draught sealing 1
Post retrofit
test
Curtainsand
pelmets
Energy bills
Electricity usage
Energy use 2011 (kWh/day) Energy use 2012 (kWh/day) Difference
Autumn* 44 18 –60%
Winter* 65 18 –73%
Predicted versus actual reductions in energy useThermalsimulationsuggestedthatreductionsinenergyuseof18%forheatingandcoolingcouldbeachievedviathedraught-sealingandwindow-dressingmeasuresimplemented.
Actualenergyconsumptiondatafromquarterlybillsdemonstratea73%reductioninoverallhouseholdenergyuse(i.e.notjustheatingandcoolingbutalsoappliances,lighting,hotwaterheating,etc.)betweenwinter2011andwinter2012.Thissuggeststhateducationandassociatedbehaviourchangecouldaccountformostofthereductioninenergyconsumption.In2011,theclienthadbeenunwellandhadanotherfamilymemberstayinginthehouse.Asaresult,theinefficientelectricslabheatingsystemhadbeenusedthroughoutthewholehouseratherthanbeingzonedforuseintheendofthehouseoccupiedbytheresidentonhisown.
Total energy, greenhouse gas and cost savings
Energy saving (kWh) CO2-e saving (kg)a Cost saving ($)b
Autumn* 2395 2538.76 326.87
Winter* 4269 4525.82 685.84
a Scope2+Scope3emissionfactorforelectricityis1.06kgCO2-e/kWh(source:AustralianGovernmentDepartmentofClimateChangeandEnergyEfficiency,National Greenhouse Gas Accounts factors,July2012).
b Peak/off-peakrateisusedtocalculatecostsavingsforelectricityusage.
*Autumn=billingperiodsbeginninginMarch–May;winter=billingperiodsbeginninginJune–August
44 OutreachEnergyandWaterEfficiencyProgram-Casestudyreport
Case study 4Communitywelfareorganisation:SocietyofStVincentdePaul
Serviceprovider:C&JGroup
Background information from Energy Efficiency Officer
Category Homeisdraughty,withnocurtainsorblinds,andtheclienteitherhashighbillsorislivinginimpoverishedconditions.Clientwouldbenefitgreatlyfromanassessment,educationandbasicretrofit.
Household occupants 3
Financial circumstance Centrelink—singleparent
Type of residence ACTHousing
Products to be replaced Refrigeratorandwashingmachinealreadyreplaced
Draught sealing required?
Notsure
Client concerns Verycoldhouse;theclientisconcernedaboutwinterbillaffordability.Thehousehaspelmetsbutnocurtains.Theopen-planliving/diningareaisapriority.
Date of referral 27March2012
The house, its timeline of retrofitting activities and thermal performanceThree-bedroombrickveneer,98m2,approximately35yearsold.
Thepotentialforpassivesolarheatgaintothishouseislimited.Thelargeareaofglazinginthemainlivingareaandthewindowsofbedrooms2and3facesouth-west.Thesmallamountofsolarheatgainpossibleviathediningwindowisquicklylostthroughtheleakybuildingenvelopetothesurroundinguninsulatedwalls.Themainbedroomonthesouthernmostcornerofthehouseisextremelycold,withtwolargeuninsulatedexternalwallsandnoopportunityforsolarheatgain.
Thethermalperformancesimulationshowedthat:
• retrofittingwallinsulationisthesinglemosteffectiveretrofitmeasureforthishome,withapredicted27.9%reductioninenergyrequirementsforheatingandcooling
• draughtsealingceilingventsandfittingdamperstoexhaustfansisthemostcost-effectiveoptionatonly$14perMJ/m2reductioninpredictedenergyrequirements.
Thebestallocationoftheretrofitbudgetwas$500—draughtseal;$3100—draughtsealandinsulatewalls;$5100—draughtseal,insulatewallsandtop-upceilinginsulation.
Aerial view ↑North Modelled in BERS4.2 thermal simulation software Pink: kitchen/dining; purple: living; blue: bedrooms; green: laundry/bathroom; yellow: corridor
environment.act.gov.au 45
Timeline of testing and retrofitting activities
Date Action
18April Temperatureandenergy-usedataloggersinstalled
3May Airleakageassessmentandthermographicinspection
7–11May Education
29May–1June Draught-proofing
6June Ceilinginsulationinstalled
7June Hollandblindsinstalled
22June Post-retrofittestandcollectionoftemperatureandenergy-usedata
22Juneonwards Temperaturedataloggerslostinclient’shome
2August Wallinsulationinstalled
28August Draught-proofinginternalbathroomandtoiletdoors
Thermal performance simulation (energy efficiency rating) of proposed retrofit measures
Simulation and specifications
Star rating
Heating (MJ/m2)
Cooling (MJ/m2)
Total (MJ/m2)
Predicted reduction (%)
Actual cost ($)
Cost per MJ reduction ($)
Startingconditions:•CeilingsR2,walls/floorsR0•Multipleceilingvents•Openexhaustfaninkitchen•Lightcurtains(2layers)
2.9 354 35 390
Startingconditionsplus:•Draughtsealing•DraftStoppa®tokitchenexhaust
3.3 321 34 355 9 311 9
Startingconditionsplus:•Newblindstoloungeanddining
2.9 354 35 390 0 1292 Novalue
Startingconditionsplus:•WallR2insulation•Associatedelectricalupgrade
3.9 259 29 288 26 4127 40
Startingconditionsplus:•CeilingR4insulation•Removalofoldinsulation
4.2 244 23 267 32 2045 16
Completeretrofit:•Sealedexhaustfans•Sealedvents•Draughtsealed•DraftStoppa®tokitchenexhaust
•Newblindstoloungeanddining
•R2inwallsandR4inceiling
4.7 211 21 232 41 7775 49
46 OutreachEnergyandWaterEfficiencyProgram-Casestudyreport
Air leakage resultsVisualinspectionsuggestedthatthehousewouldbeveryleaky,andthiswasconfirmedbyfandepressurisationtesting.Thebuildingenvelopehadmanyobviousleakagepoints,including:• unsealedexhaustfaninkitchenandbathroom
• permanentceilingventsineveryroom
• permanentopeningintoiletwindow
• arounddoorsandsurroundingarchitraves
• betweenwindowarchitravesandgyprock
• viaplumbingandelectricalpenetrationsbehindkitchenjoinery.
Therateofairleakagewasnearlyhalvedafterthefollowingdraught-sealingmeasureswereimplemented:
• installingDraftStoppa®onkitchenandbathroomfans
• caulkingaroundsomedoorwaysandwindowsframes
• sealingofthepermanentceilingvents.
Althoughunwantedairleakagewassignificantlyreduced,thereisscopeforfurtherretrofittingworkonthebuildingenvelope.Moretimeandbudgetgiventosealingthebuildingenvelopewouldyieldfurthergainsinairtightness,improvementsincomfortandreductionsinenergyuse.
Althoughthethermachrondata(see‘Temperatureandelectricityuse’)donotshowanincreaseininternaltemperatures,theclientissurethatthehousefeelsmuchmorecomfortable.
Result from air leakage testing
Pre-retrofit Post-retrofit Difference
Airchangesperhourat50Pa 25.01 13.89 –45%
Effectiveleakageareaat4Pa(equivalentopensquarewindow)
51cmx51cm 37cmx37cm 35cmx35cm
Note: Apressuredifferenceof4Pabetweeninsideandoutsideisclosetothenormalpressuredifferentialexperiencedinthehomeoncold,windyCanberradays.
Air Leakage points
Unsealed exhaust fan in kitchen Ceiling vent in bedroom Between architrave and gyprock
environment.act.gov.au 47
InsulationThermalimagingshowedthatthewallswereuninsulated.Ceilinginsulation,althoughpresent,appearedtobethinandpatchyinsomeareas.Onamild,sunnydayinMarch,thewallsofthemasterbedroomwereatapproximately13°C;theceilingwasat14.5°C.
Inadequate insulation
Main bedroom, south corner, ceiling 5 March 2012, 10:28:37 am
Main bedroom, south corner, walls 5 March 2012, 10:28:46 am
Main bedroom, south-west wall 5 March 2012, 10:51:47 am
Temperature and electricity useResultsfromthetemperaturedataloggershighlightthefollowing:
• Thisisaverycoldhouse.Theinternaltemperatureisonly5°Chigherthantheexternaltemperature.Atsomepointinthemiddleoftheday,theexternaltemperaturealmostmatchestheinternaltemperature.
• Post-retrofitting,internaltemperaturesremainedconstantdespiteadecreaseinenergyusebytheclient.Thisindicatesthatthehousemaintainstemperatureasaresultofimprovedinsulationanddraught-proofing.
• Unfortunately,aroundthesametimethatwallinsulationwasinstalled,anotherpersonmovedintothehouse,andtheenergy-useprofileofthehousechangeddramatically.Theincreasedenergyusewasnotassociatedwithheating.
Electricity use and temperature data in case study 4
Tem
pera
ture
(0 C)
Electricity use (kWh)
50 50
40 40
30 30
20 20
10 10
0 0
Bedroom temperature External temperature Kitchen temperature Lounge temperature Main bedroom temperature Electricity use
1 M
AY
1 JU
NE
1 AU
GUST
1 JU
LYLeakage test andeducation
Draught sealing 1
Wallinsulation
Curtainsand ceilinginsulation
Post retrofit
test
Draught sealing 2
Electricity use
48 OutreachEnergyandWaterEfficiencyProgram-Casestudyreport
Energy bills
Electricity usage
Energy use 2011 (kWh/day) Energy use 2012 (kWh/day) Difference
Autumn* 33 21 –35%
Winter* 74 42 –42%
Other observationsAsaresultofherinvolvementwiththeprogram,theclienthasmadeagreatefforttoreduceherenergybills.Shesayssheismuchmoreconsciousofenergyuseandhowtoreduceit.Followinghereducationsession—andlearningthedifferencebetweenpeakandoff-peakpower—shehaschangedsomewell-wornroutinesandnowdoesherwashingatnight.
Otherchangestheclienthasmadeinclude:
• turningheatingononlyinthemorningandevening
• turningheatingoffinthebedroomovernight
• turningappliancesoffatthewall
• closingcurtainstokeeptheheatinside
• dressingfortheclimate
• talkingwithSpotlessaboutpossibleupgradingofheatingtoanefficientsplit-systemforthelounge/diningarea.
Total energy, greenhouse gas and cost savings
Energy saving (kWh) CO2-e saving (kg)a Cost saving ($)b
Autumn* 1056 1119.80 133.41
Winter* 2780 2947.20 418.30
a Scope2+Scope3emissionfactorforelectricityis1.06kgCO2-e/kWh(source:AustralianGovernmentDepartmentofClimateChangeandEnergyEfficiency,National Greenhouse Gas Accounts factors,July2012).
b Peak/off-peakrateisusedtocalculatecostsavingsforelectricityusage.
*Autumn=billingperiodsbeginninginMarch–May;winter=billingperiodsbeginninginJune–August
environment.act.gov.au 49
Case study 5Communitywelfareorganisation:NorthsideCommunityService
Serviceprovider:C&JGroup
Background information from Energy Efficiency Officer
Category Clientwouldbenefitfromanassessment,educationandbasicretrofit,suchascurtains,blindsanddraughtsealing
Household occupants 3
Financial circumstance Disabilitysupportpension
Type of residence Owner–occupier
Products to be replaced Washingmachine,refrigeratorandfreezer
Draught sealing required?
Couldbenefitfrompelmets.Sensorlightstaysonallthetime.Gasheatingsettingsarefaulty.Insulationinceilingisalmostnon-existent,andthereisnoinsulationinwalls.
Date of referral 11April2012
The house, its timeline of retrofitting activities and thermal performanceThreebedrooms,onebathroom,brickveneer,suspendedtimberfloor,100m2,35yearsold.
Themainlivingroomhasglazingtothenorth-east,withgoodpotentialforpassivesolarheatgaintotheareaofgreatestenergyuse.However,thelivingareaisopentotheadjoiningdiningarea,whichisglazedtothesouthandwest.Thisadditionalspaceandtheorientationofthewindowsreducetheabilityofthejointliving/diningareastoretainheat.Thelargestbedroomhasarelativelyhighglazing-to-floor-arearatio,andthewindowsareorientedtothewestandsouth—thesefeaturesmakeitathermalweakpoint.Uninsulatedwalls,alargenumberofceilingpenetrationsandpatchyceilinginsulationsignificantlyaffecttheamountofenergyrequiredtomaintaincomfortabletemperatures.
Thisclienthasrecentlyconnectedsolarpanels,andthesolarfeed-intariffisoffsettinganybills.
Thethermalperformancesimulationindicatedthatdraughtsealingwouldprovidea16%reductioninenergyuseforalowcost.
Aerial view ↑North Modelled in BERS4.2 thermal simulation software Pink: kitchen/dining; red: living; blue/purple: bedrooms; green: laundry/bathroom; yellow: corridor
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Timeline of testing and retrofitting activities
Date Action
9May Temperatureandenergy-usedataloggersinstalled
21May Education
23May Airleakageassessmentandthermographicinspection
29May Draught-proofing
31May Top-upinsulation,curtainsandpelmetsinstalled
17June Post-retrofittestandcollectionoftemperatureandenergy-usedata
22June Finalblowerdoortestanddatacollection
Thermal performance simulation (energy efficiency rating) of proposed retrofit measures
Simulation and specifications
Star rating
Heating (MJ/m2)
Cooling (MJ/m2)
Total (MJ/m2)
Predicted reduction (%)
Actual cost ($)
Cost per MJ reduction ($)
Startingconditions:•CeilingsR2,walls/floorsR0•Multipleceilingvents(eachroom)
•Openexhaustfaninkitchen•Lightcurtains/blinds
2.8 396 34 430
Startingconditionsplus:•Draughtsealing
3.2 329 34 363 16 675 10
Startingconditionsplus:•InsulationR2inceiling
2.7 385 27 412 4 1920 106
Startingconditionsplus:•Curtainsandpelmetstolounge,diningandkitchen
2.8 386 34 420 2 2720 272
Completeretrofit:•Sealedexhaustfans•Sealedvents•Draughtsealed•R4inceiling•Curtainsandpelmetstolounge,diningandkitchen
3.4 313 26 339 21 5315 58
Air leakage results
Sourcesofairleakageincluded:
• permanentceilingventsineveryroom,includinglargeceilingventdirectlyabovefluedgasheaterinlivingroom
• openexhaustfaninkitchen
• unsealed‘Tastic’inbathroom
• arounddoorsandwindowframes
• aroundceilingandwallpenetrations,suchasroofaccessholeandwall-mountedair-conditioningsystems.
environment.act.gov.au 51
Therateofairleakagewasreducedby41%byinstallingaDraftStoppa®inthekitchen,sealingoffunnecessaryceilingventsandsealingaroundexternaldoors.
Thepermanentventsandotherpenetrationsintheceilingseriouslycompromisedthepotentialofthehousetostaywarm.Heatedairfromwithinthehomewasrisingandrapidlyescapingintotheroofspaceviatheholesintheceiling.
Thereductioninairleakageachievedinthishome,byfocusingmainlyontheholesintheceiling,isequivalenttoclosinga31cmx31cmwindowinthebuildingenvelope.
Result from air leakage testing
Pre-retrofit Post-retrofit Difference
Airchangesperhourat50Pa 21.02 12.46 –41%
Effectiveleakageareaat4Pa(equivalentopensquarewindow)
49cmx49cm 38cmx38cm 31cmx31cm
Note: Apressuredifferenceof4Pabetweeninsideandoutsideisclosetothenormalpressuredifferentialexperiencedinthehomeoncold,windyCanberradays.
Air Leakage points
Gap through architrave and around door
One of many ceiling vents Leakage around roof access hole
InsulationTheroofhadrockwoolinsulationthatwasthinandunevenlyinstalled.Thiscausedsignificantfluctuationsinceilingtemperaturethroughoutthehouse.Thermalimagingindicatedthatnowallinsulationwaspresent(asexpectedinahouseofthisage).
Inadequate insulation
Living area, no wall insulation Lounge area, patchy ceiling insulation
52 OutreachEnergyandWaterEfficiencyProgram-Casestudyreport
Temperature and electricity usePassiveventilationthroughoutthishomeviamultipleceilingventsandotherunsealedpenetrationsisresponsibleforthelargefluctuationsininternaltemperature.Datafromthethermochronshighlightthefollowing:
• Beforetheretrofit,internaltemperatureswereregularlyonly8°Cwarmerthantheexternaltemperature.Aftertheretrofit,theywereregularly10°Cwarmerthantheexternaltemperature.
• Thekitchen/diningareaiswarmerafterretrofittingandreachesamaximumtemperatureabove20°Cmoreoften.
• Followingtheretrofit,thehomemaintainshighertemperaturesandexperienceslessfluctuationintemperature,butenergyusehasdecreased.
Electricity use and temperature data in case study 5
Tem
pera
ture
(0 C)
Electricity use (kWh)
50 50
40 40
30 30
20 20
10 10
0 0
Bedroom temperatureExternal temperatureKitchen temperatureElectricity use
1 JU
NE
1 JU
LYEducation and leakage test
Draught sealing and curtains/pelmets
and top-up insulation
Electricity use
Post retrofit
test
Energy billsAgasheaterisusedtomaintainthelivingareasatcomfortabletemperatures.Electricreverse-cyclesystemsareusedinthebedrooms.Gasconsumptiondecreased,butelectricityconsumptionwasstable.
Electricity usage
Energy use 2011 (kWh/day) Energy use 2012 (kWh/day) Difference
Autumn 19 22 +14%
Winter 18 19 +5%
Gas usage
Energy use 2011 (kWh/day) Energy use 2012 (kWh/day) Difference
Autumn 112 98 –12.5%
Winter 120 87 –27.5%
Electricity + gas usage
Energy use 2011 (kWh/day) Energy use 2012 (kWh/day) Difference
Autumn 131 120 –8%
Winter 138 106 –23%
*Autumn=billingperiodsbeginninginMarch–May;winter=billingperiodsbeginninginJune–August
environment.act.gov.au 53
Predicted versus actual reductions in energy useThermalsimulationsuggestedthatreductionsinenergyuseof21%forheatingandcoolingcouldbeachievedviathedraught-sealingandwindow-dressingmeasuresimplemented.
Actualenergyconsumptiondatafromquarterlybillsdemonstratea23%reductioninoverallhouseholdenergyuse(i.e.notjustheatingandcoolingbutalsoappliances,lighting,hotwaterheating,etc.)betweenwinter2011andwinter2012.Thissuggeststhateducationandassociatedbehaviouralchangecouldaccountfortheextrareductioninenergyconsumption.
Total energy, greenhouse gas and cost savings
Energy saving (kWh) CO2-e saving (kg)a Cost saving ($)b
Autumn* 1038 –14.84 61.18
Winter* 2921 467.85 213.82
a Scope2+Scope3emissionfactorforelectricityis1.06kgCO2-e/kWh.Emissionfactorfornaturalgasis51.33kgCO2-e/GJ(source:AustralianGovernmentDepartmentofClimateChangeandEnergyEfficiency,National Greenhouse Gas Accounts factors,July2012).
b Costsavingsforgasusagecalculatedusing2.113centspermegajoule
*Autumn=billingperiodsbeginninginMarch–May;winter=billingperiodsbeginninginJune–August
54 OutreachEnergyandWaterEfficiencyProgram-Casestudyreport
Case study 6Communitywelfareorganisation:BelconnenCommunityService
Serviceprovider:CoolPlanet
Background information from Energy Efficiency Officer
Category Clientwouldbenefitfromanassessment,educationandbasicretrofit,suchascurtains,blindsanddraughtsealing
Household occupants 2
Financial circumstance Youngsinglemotheronpartpensionandpart-timework;largeenergybills
Type of residence HousingACTsinglestorey,2bedrooms,brickveneer,northfacing
Products to be replaced Refrigeratorandwashingmachinealreadyreplaced
Draught sealing required? Contractorengaged
Client concerns Theclienthaslivedinthishomeforoneyear.Shereportsthatthehomeisverycoldinwinterandveryhotinsummer.Thereisawall-mountedelectricheater,whichshetriesnottousebecauseofcosts.Therearelightblock-outcurtainsinallrooms,butnopelmets.Therearethreelargeventsthroughoutthehome:twoareforventilationandtheotherisaskylight.Theclientreportsmassivedraughtsfromthese.Therearealsogapsaroundandunderdoors,whichsheblockswith‘doorsnakes’.Shehasenergy-efficientlightinginherhomeandisawareofenergyefficiency,butwouldlikefurthereducationandinformationtomakechoicesaboutherheating.EnergyEfficiencyOfficertalkedabouttheuseofpassiveheatingthroughnorth-facingwindows,aheatedthrowrugandcolumn-heateruse,aswellashighlightingthepotentialfortheretrofittoincreasethecomfortofherhome.
Date of referral 6April2012
The house, its timeline of retrofitting activities and thermal performanceTwo-bedroom,brick-veneertownhouse.
Thepotentialforpassivesolarheatgaintothishouseisgoodasaresultofthelargeareaofnorth-facingglazinginthelounge/living/kitchenarea.Thetwobedroomshavesouth-facingwindows.Themainissuewiththishouseistheventedskylightsusedinthekitchenandbathroomsforventilationandlight.
Thethermalperformancesimulationindicatesthatdraughtsealingceilingventsandfittingdamperstoexhaustfansisthesinglemosteffectiveretrofitmeasureforthishome,withapredicted21%reductioninenergyrequirementsforheatingandcooling.
Thebestallocationoftheretrofitbudgetwas$700—draughtseal;$1700—draughtsealandtop-upinsulationinceiling.
Aerial view ↑North Modelled in BERS4.2 thermal simulation software Pink: kitchen/dining/living; brown: garage; blue: bedrooms; green: laundry/bathroom; yellow: corridor
environment.act.gov.au 55
Timeline of testing and retrofitting activities
Date Action
18April Temperatureandenergy-usedataloggersinstalled
10May Airleakageassessmentandthermographicinspection
6June Ceilinginsulationinstalled
11June Draught-proofing
12June Education
20June Draught-proofingbathroom,newextractorfaninstalled,andinvestigationofdampinchild’sbedroom
22June Post-retrofittest,andcollectionoftemperatureandenergy-usedata
Thermal performance simulation (energy efficiency rating) of proposed retrofit measures
Simulation and specifications
Star rating
Heating (MJ/m2)
Cooling (MJ/m2)
Total (MJ/m2)
Predicted reduction (%)
Actual cost ($)
Cost per MJ reduction ($)
Startingconditions:•CeilingsR3.5,wallsR1.5•Openexhaustfan•Draughtsealed•Nopelmets,lightdressing•Open-shaftskylightsx3
4.2 252 16 268
Startingconditionsplus:•Pelmetsx6
4.4 237 16 253 6 720 48
Startingconditionsplus:•Sealedexhaustfan•Sealedskylights
4.9 204 17 221 18 1578 34
Completeretrofit:•Sealedexhaustfans•Sealedskylights•Pelmetsx6
5.2 189 17 206 23 2298 37
Air leakage resultsTheoverallconditionandbuildofthehousewasreasonablygood,asexpectedforahouselessthan10yearsold.TheinitialairleakagedatashowedhigherthanaverageairexchangeratesforCanberrahomes.Thiswasmainlyduetothreevented-shaftskylightsinthebathroomsandtheopen-plankitchen/livingarea.Thesewereventedtotheroofcavityandallowedlargevolumesofairtoriseandescape.
Thissimplebuildingoversightanddesignflawwaseasilyrectifiedbyaddingsealedexhaustfansineachbathroomandsealingtheshaftswithremovableperspex.
Theimagesbelowshowtheairexchangeoccurringthroughtheskylights.Itisinterestingtonotethedifferenceintemperaturebetweentheairintheskylightshaftandthesurrounds—theairintheshaftiswarmer,partlyasaresultofthestackeffect,aswellasthesolarheatgainthroughtheshaftfromthemorningsun.
Airinfiltrationcanalsobeseenaroundtheroofaccessholeanddoors.Thesegapsaccountforthebulkoftheremainingunwantedairexchange.
56 OutreachEnergyandWaterEfficiencyProgram-Casestudyreport
Therateofairleakagewasreducedby75%afterdraughtsealingtheventedskylightsandaroundtheexternaldoors.Thereductioninairleakageachievedinthishome,byfocusingmainlyontheholesintheceiling,isequivalenttoclosinga25cmx25cmwindowinthebuildingenvelope.
Result from air leakage testing
Pre-retrofit Post-retrofit Difference
Airchangesperhourat50Pa 28.2 7.1 –75%
Effectiveleakageareaat4Pa(equivalentopensquarewindow)
48cmx48cm 23cmx23cm 42cmx42cm
Note: Apressuredifferenceof4Pabetweeninsideandoutsideisclosetothenormalpressuredifferentialexperiencedinthehomeoncold,windyCanberradays.
Air Leakage points
Vented skylight in kitchen Vented skylight and fan in bathroom
Leakage around roof access hole in laundry
InsulationTheroofwasreasonablyinsulated,butthewallshadnoinsulation.Theimagesbelowindicatethetemperaturedifferencesbetween:
• thewallsandtheceiling(showingtheeffectofinsulation)
• insulatedanduninsulatedsectionsoftheceiling
• internalandexternalwalls(wheretheinternalwallsareprotectedfromlargetemperaturefluctuationsbythesemi-conditionedspaceofthegarage).
Inadequate insulation
Insulated ceiling and uninsulated wall
Patchy ceiling insulation 5 October 2012, 10:36:38am
Internal and external walls 5 October 2012, 10:45:31am
Temperature and electricity useThedatagatheredshowthatenergyusestayedthesame(around40kWh/day)followingretrofitting.
Passiveventilationthroughoutthishomeviamultipleventedskylightsandotherunsealedpenetrationsisresponsibleforthelargefluctuationsininternaltemperature.Theenergyuseisthesamefollowingretrofit,buttheinternaltemperatureofthehomehasdramaticallyincreased.Thismaybeduetotheclientenjoyingthe
environment.act.gov.au 57
feelingofwarmthinherhomeornotbeingfullyawarethatheatingisstillbeingusedandtheneedtolowerthethermostat.Thishighlightstheneedforfollow-upeducationsessionsfollowingretrofittingmeasuressothatclientsareawareofhowtheycanreducetheirenergyuse.
Electricity use and temperature data in case study 6
Tem
pera
ture
(0 C)
Electricity use (kWh)
50 50
40 40
30 30
20 20
10 10
0 0
Bedroom temperature External temperature Living room temperature
Electricity use1
MAY
1 JU
NELeakage
testingCeiling
insulationinstalled
Draught sealing 2
Postretrofit test
Educationdraught sealing 1
Electricity use
Energy bills
Electricity usage
Energy use 2011 (kWh/day) Energy use 2012 (kWh/day) Difference
Autumn* 23 14 –40%
Winter* 67 44 –35%
Predicted versus actual reductions in energy useThermalsimulationsuggestedthatreductionsinenergyuseof23%forheatingandcoolingcouldbeachievedviathedraught-sealingandwindow-dressingmeasuresimplemented.
Actualenergyconsumptiondatafromquarterlybillsdemonstratea35%reductioninoverallhouseholdenergyuse(i.e.notjustheatingandcoolingbutalsoappliances,lighting,hotwaterheating,etc.)betweenwinter2011andwinter2012.Thissuggeststhateducationandassociatedbehaviouralchangecouldaccountfortheextrareductioninenergyconsumption.
Total energy, greenhouse gas and cost savings
Energy saving (kWh) CO2-e saving (kg)a Cost saving ($)b
Autumn* 845 895.79 128.03
Winter* 2103 2229.09 345.65
a Scope2+Scope3emissionfactorforelectricityis1.06kgCO2-e/kWh(source:AustralianGovernmentDepartmentofClimateChangeandEnergyEfficiency,National Greenhouse Gas Accounts factors,July2012).
b Actualratesforautumnandwinter2012wereusedtocalculatethecostsavingsforelectricityusage.
*Autumn=billingperiodsbeginninginMarch–May;winter=billingperiodsbeginninginJune–August
58 OutreachEnergyandWaterEfficiencyProgram-Casestudyreport
Case study 7Communitywelfareorganisation:Communities@Work
Serviceprovider:CoolPlanet
Background information from Energy Efficiency Officer
Category Homeisdraughty,withnocurtainsorblinds,andtheclienteitherhashighbillsorislivinginimpoverishedconditions.Clientwouldbenefitgreatlyfromanassessment,educationandbasicretrofit.
Household occupants 3
Financial circumstance Low-incomehousehold
Type of residence Owner–occupier
Products to be replaced Refrigeratorandwashingmachine
Draught sealing required? Requiresdraught-proofingtoaddressairleakage.Requireswindowfurnishing,includingpelmets,toreducecurrenthighlossthroughaluminium-framedsingle-glazedwindows.Insulationtoceilingandwallsrequiressurveyandsubsequentrectification—minimumR5toceilings,R3towalls.
Client concerns Coldinwinter,hotinsummer
Date of referral 5May2012
The house, its timeline of retrofitting activities and thermal performanceTwo-bedroom,brick-veneertownhouse.
Thethermalperformancesimulationindicatesthatdraughtsealingshouldbetwiceascost-effectiveaswindow-dressingupgradesinthishouse.
Aerial view ↑North Case study 7 is the unit in the centre
Modelled in BERS4.2 thermal simulation software Pink: kitchen/dining/living; blue/purple: bedrooms; green: laundry/bathroom; yellow: corridor
Timeline of testing and retrofitting activities
Date Action
18May Temperatureandenergy-usedataloggersinstalled
7June Airleakageassessmentandthermographicinspection
12July Draught-proofing
24July Education
27July Post-retrofittestandcollectionoftemperatureandenergy-usedata
July–September Furtherdraught-proofingcavitydoorsliderandwall–ceilingjoins(exactdateunclear)
19September Curtainsandpelmetsinstalled
environment.act.gov.au 59
Thermal performance simulation (energy efficiency rating) of proposed retrofit measures
Simulation and specifications
Star rating
Heating (MJ/m2)
Cooling (MJ/m2)
Total (MJ/m2)
Predicted reduction (%)
Actual cost ($)
Cost per MJ reduction ($)
Startingconditions:•CeilingsR3.5•Down-lightsx4•Openexhaustfaninkitchen,open-shaftskylightinbathroom
•Verydraughty
3.3 290 18 309
Startingconditionsplus:•Curtainstolivingareas•Blindtokitchen
4.3 244 19 260 16 1720 35
Startingconditionsplus:•Exhaustfancover•Down-lightcoversx4•Sealedskylight•Draughtsealing2xdoors/windows
4.2 256 19 274 11 561 16
Completeretrofit•Curtainstolivingareas•Blindtokitchen•Exhaustfancover•Down-lightcoversx4•Sealedskylight•Draughtsealing2xdoors/windows
4.9 207 15 222 28 2282 26
Air leakage resultsThehousewasbuiltinthelast10–20yearsandisinreasonablecondition.Ithasagoodnortherlyaspecttothelivingroomandtwobedrooms.Thehouseperformedreasonablywellduringinitialtestingwithrespecttoairleakage.However,giventhesmallsizeofthehouseandtheorientation,therewasplentyofscopeforimprovement.
Initialtestingofthebuildingshowedareasonablytightbuildingenvelope,withsomemajorpitfalls.Themainleakagewasaresultofanopen-shaftskylight,wall-mountedpanelheaterandventedrefrigeratorspace.Otherareasofleakageinclude:
• betweeninternalbrickandplasterboardinternalwalls
• betweenbricksandwindowframes,aswellassliding-doorframe
• throughinternal-wallsliding-doorframe
• gapswherebrickworkmeetsceiling
• unsealedexhaustfaninkitchen
• permanentopeningabovefridge
• unsealedopen-shaftskylight
• cavityslidingdoor
• wall-mountedpanelheater
• roofaccesshole.
60 OutreachEnergyandWaterEfficiencyProgram-Casestudyreport
Airleakagewasreducedby:
• sealingbetweentheinternalbrickwallandadjoiningwallsandcornicing
• installationofaDraftStoppa®abovethetoiletfan
• sealingarounddoorframesandcatches
• sealingaroundarchitravesanddoorframes
• sealingtheskylightinthebathroom.
Result from air leakage testing
Pre-retrofit Post-retrofit Difference
Airchangesperhourat50Pa 16.8 10.19 –40%
Effectiveleakageareaat4Pa(equivalentopensquarewindow)
34cmx34cm 23cmx23cm 25cmx25cm
Note: Apressuredifferenceof4Pabetweeninsideandoutsideisclosetothenormalpressuredifferentialexperiencedinthehomeoncold,windyCanberradays.
Air Leakage points
Leakage between architrave and gyprock
Leakage around roof access hole Leakage through sliding cavity door
Temperature and electricity useTheresultssuggestthatenergyusedecreased,andinternaltemperaturesincreasedinmid-Julyfollowingdraughtsealing.Theresultsareveryerratic,however,andthisisthoughttoberelatedtothehomeownerfrequentlygoingawayforextendedperiods.
environment.act.gov.au 61
Electricity use and temperature data in case study 7
Draught sealing 1
Draught sealing 1
Education Curtains and pelmets
Postretrofit
test
Tem
pera
ture
(0 C)
1 AU
G
1 SE
PT
5 5
10 10
15 15
20 20
25 25
30 30
35 35
0 0
1 JU
NE
1 JU
LY
Hallway temperatureExternal temperatureKitchen temperatureElectricity use Electricity use
Leakage test
Energy bills
Electricity usage
Energy use 2011 (kWh/day) Energy use 2012 (kWh/day) Difference
Autumn* 7 8 14%
Winter* 9 15 62%
Gas usage
Energy use 2011 (kWh/day) Energy use 2012 (kWh/day) Difference
Autumn* 19 16 –16%
Winter* 43 36 –16%
Electricity + gas usage
Energy use 2011 (kWh/day) Energy use 2012 (kWh/day) Difference
Autumn* 28 24 –14%
Winter* 52 51 –2%
Total energy, greenhouse gas and cost savings
Energy saving (kWh) CO2-e saving (kg)a Cost savings ($)b
Autumn* 176 –52.25 6.1
Winter* 117 –434.05 –38.47
a Scope2+Scope3emissionfactorforelectricityis1.06kgCO2-e/kWh.Emissionfactorfornaturalgasis51.33kgCO2-e/GJ(source:AustralianGovernmentDepartmentofClimateChangeandEnergyEfficiency,National Greenhouse Gas Accounts factors,July2012).
b Costsavingsforgasusagecalculatedusing2.113centspermegajoule*Autumn=billingperiodsbeginninginMarch–May;winter=billingperiodsbeginninginJune–August
62 OutreachEnergyandWaterEfficiencyProgram-Casestudyreport
Case study 8Communitywelfareorganisation:Communities@work
Serviceprovider:CoolPlanet
Background information from Energy Efficiency Officer
Category Homeisdraughty,withnocurtainsorblinds,andtheclienteitherhashighbillsorislivinginimpoverishedconditions.Clientwouldbenefitgreatlyfromanassessment,educationandbasicretrofit.
Household occupants 3
Financial circumstance Low-incomehousehold
Type of residence HousingACTtenant
Products to be replaced Nil—awaitingcasestudy
Draught sealing required? Draughty,highairleakagehome,requiresdoor-baseanddoor-framesealing
Client concerns Coldinwinter,hotinsummer,highenergybills
Date of referral 17May2012
The house, its timeline of retrofitting activities and thermal performanceFour-bedroom,brickveneertownhouse,approximately40yearsold.
Thethermalperformancesimulationindicatesthatdraughtsealingwouldbefivetimesmorecost-effectivethanwindow-dressingupgradesinthishouse.
Aerial view ↑North Modelled in BERS4.2 thermal simulation software Pink: kitchen/dining; red: living; blue/purple: bedrooms; green: laundry/bathroom; yellow: corridor
Timeline of testing and retrofitting activities
Date Action
24May Temperatureandenergy-usedataloggersinstalled
7June Airleakageassessment
7July Draught-proofing
12July Draught-proofingofbathroomexhaustfan/skylight
27July Post-retrofittestandcollectionoftemperatureandenergy-usedata
5December Curtainsandpelmetsinstalled
environment.act.gov.au 63
Thermal performance simulation (energy efficiency rating) of proposed retrofit measures
Simulation and specifications
Star rating
Heating (MJ/m2)
Cooling (MJ/m2)
Total (MJ/m2)
Predicted reduction (%)
Actual cost ($)
Cost per MJ reduction ($)
Startingconditions:•CeilingsR3•Unsealedexhaustfaninkitchenandbathroom
•Verydraughty
2.8 318 28 346
Startingconditionsplus:•Curtainstolivingareas
2.9 303 25 328 5 1570 87
Startingconditionsplus:•Exhaustfancovers•Draughtsealing
3.1 282 28 310 10 575 16
Completeretrofit:•Curtainstolivingareas•Exhaustfancovers•Draughtsealing
3.4 267 25 291 16 2145 39
Air leakage resultsThishousehadasurprisinglytightbuildingenvelopeforitsage,mainlyasaresultofitslackofceilingandwallvents,whichcanbecommoninthesehouses,anditsarchitravesandcornicing,whichwereinreasonablecondition.
Measurestoreduceairleakageincluded:
• sealingtwoexhaustfansusingDraftStoppas®
• resealingsomearchitravesusingsealant
• sealingexternaldoorwaysaroundthesidesandatthebottom.
Withthesefairlyminormodifications,thehousereachedcloseto10airchangesperhourat50Pa.Tofurtherreduceairleakage,thehousewouldrequirenewwindowsthatsealmoreeffectively.
Result from air leakage testing
Pre-retrofit Post-retrofit Difference
Airchangesperhourat50Pa 16.03 10.42 –36%
Effectiveleakageareaat4Pa(equivalentopensquarewindow)
40cmx40cm 33cmx33cm 23cmx23cm
Note: Apressuredifferenceof4Pabetweeninsideandoutsideisclosetothenormalpressuredifferentialexperiencedinthehomeoncold,windyCanberradays.
Refrigerator replacement
Energy usage results for old and new refrigerators
Energy use (kWh/day) Energy use (kWh/year) CO2-e (kg/year)a Difference
Old 2.3 839 889
New 0.91 334 354 –61%
a Scope2+Scope3emissionfactorforelectricityis1.06kgCO2-e/kWh(source:AustralianGovernmentDepartmentofClimateChangeandEnergyEfficiency,National Greenhouse Gas Accounts factors,July2012).
64 OutreachEnergyandWaterEfficiencyProgram-Casestudyreport
Energy bills
Electricity usage
Energy use 2011 (kWh/day) Energy use 2012 (kWh/day) Difference
Autumn* 54 51 –6%
Winter* 67 58 –13%
Predicted versus actual reductions in energy useThermalsimulationsuggestedthatreductionsinannualenergyforheatingandcoolingof16%couldbeachievedviathedraught-sealingandwindow-dressingmeasuresimplemented.
Actualenergyconsumptiondatafromquarterlybillsdemonstratea13%reductioninoverallhouseholdenergyuse(i.e.notjustheatingandcoolingbutalsoappliances,lighting,hotwaterheating,etc.)betweenwinter2011andwinter2012.Thedifferencebetweenactualandpredictedenergysavingsislikelytobeduetoclientbehaviour.
Total energy, greenhouse gas and cost savings
Energy saving (kWh) CO2-e saving (kg)a Cost saving ($)b
Autumn* 291 308.19 44.05
Winter* 804 852.23 138.62
a Scope2+Scope3emissionfactorforelectricityis1.06kgCO2-e/kWh(source:AustralianGovernmentDepartmentofClimateChangeandEnergyEfficiency,National Greenhouse Gas Accounts factors,July2012).
b Autumnandwinter2012rateisusedtocalculatecostsavingsforelectricityusage.
*Autumn=billingperiodsbeginninginMarch–May;winter=billingperiodsbeginninginJune–August
environment.act.gov.au 65
Case study 9Communitywelfareorganisation:YWCAofCanberra
Serviceprovider:C&JGroup
Background information from Energy Efficiency Officer
Category Clientwouldbenefitfromanassessment,educationandbasicretrofit,suchascurtains,blindsanddraughtsealing
Household occupants 1
Financial circumstance Centrelink
Type of residence ACTHousing
Products to be replaced Refrigerator
Draught sealing required?
RecommendedtoclienttocontactSpotless.Draughtsealingrequiredandinsulationcheck.Houselooksdraughty.
Client concerns Draughtyhouse,whichgetshotandcold.Curtainsexistbutaredirty;theclientisconcernedaboutprivacy,becauselivingroomwindowsfaceontoamajorroad.Possiblycouldalsoimprovethecurtaincurrentlyusedtozonethelivingarea.
Date of referral 10April2012
The house, its timeline of retrofitting activities and thermal performanceTwo-bedroom,three-storey,brick-veneerapartment,withneighbourstothenorthandsouth,approximately50yearsold.Casestudy9wasnotmodelledinBERS4.2thermalsimulationsoftwarebecauseitwasrecruitedlatetotheprogramandwasalreadya6-starhouse.
Thermal performance simulation (energy efficiency rating) of proposed retrofit measuresThermalperformancesimulationwasnotperformedbecauseofthecomplexity,anddifficultyinaccessingallareas,oftheoldthree-storeyunit.
Aerial view ↑North
Timeline of testing and retrofitting activities
Date Action
18April Temperatureandenergy-usedataloggersinstalled
11May Education
11May Airleakageassessment
25June Curtains,pelmets,lightinganddraughtsealingcompleted
13July Finalcollectionofdata
66 OutreachEnergyandWaterEfficiencyProgram-Casestudyreport
Air leakage resultsApressuredifferenceof4Pabetweeninsideandoutsideisclosetothenormalpressuredifferentialexperiencedinthehomeoncold,windyCanberradays.
Theoverallleakagerateofthisbuildingwaslowcomparedwithothercasestudyhousesbecausetheexternalwallandroofareawasrelativelysmallasaresultofitsthree-storey,multi-unitconstruction.Becausetheairleakageratewasalreadybelowourtargetof10airchangesperhourat50Pa,anditwasdifficulttotestinaconfinedentrancewayinthethree-storeyapartment,apost-retrofittestwasnotconducted.However,thereweresignificantleaksthatcouldbesealed,including:
• unsealedexhaustfaninkitchen
• permanentopeningsinwallsabovewindowsinkitchen,bathroomandlivingareas
• plumbingandelectricalpenetrationsbehindkitchenjoinery
• arounddoorsandsurroundingarchitrave,particularlyinthestaircase
• aroundoldwall-mountedheater
• betweenwindowsandgyprock,walljunctionsandroofbeams.
Measurestoaddresssomeoftheseleaksincluded:
• usingperspextosealaroundplumbingpenetrationsunderthekitchensink(althoughtherewerestillnoticeableleaksaroundthesepenetrations)
• addingsomesealantaroundarchitraves
• sealingvariousdoors.
Themainlivingareasdownstairshadapermanentopendoorframe,allowinganywarmairtoriseupthestairsandventouttheupstairspermanentopenings.
Therooflackedinsulation,andhenceanywarmaircontainedwasquicklycooledbythesurroundingcoldwalls.
Result from air leakage testing
Pre-retrofit Post-retrofit Difference
Airchangesperhourat50Pa 9.4 – –
Effectiveleakageareaat4Pa(equivalentopensquarewindow)
25cm×25cm – –
Notes: Casestudy9wasnotretestedforairleakageafterretrofittingbecauseitwasalreadybelowthetargetlevelof10airchangesperhourat50Pa,andfundswerebetterspentonhomesthatwerefurtherfromthistarget.
environment.act.gov.au 67
Temperature and electricity useThisapartmentusesaveryinefficientheatingsystemtokeepinternaltemperatures10°Chigherthanexternaltemperatures.
Electricity use and temperature data in case study 9
Tem
pera
ture
(0 C)
1 JU
NE
20 20
40 40
60 60
80 80
100 100
120 120
140 140
160 160
0 01
JULY
Electricity use
Hallway temperatureExternal temperatureElectricity use
Leakagetest and education
Draught sealingand curtains
Energy bills
Electricity
Energy use 2011 (kWh/day) Energy use 2012 (kWh/day) Difference
Autumn* 27.3 23 –16%
Winter* 146 89 –39%
Total energy, greenhouse gas and cost savings
Energy saving (kWh) CO2-e saving (kg)a Cost saving ($)b
Autumn* 399 422.84 60.43
Winter* 5185 5496.05 928.10
a Scope2+Scope3emissionfactorforelectricityis1.06kgCO2-e/kWh(source:AustralianGovernmentDepartmentofClimateChangeandEnergyEfficiency,National Greenhouse Gas Accounts factors,July2012).
b Variableratesareusedtocalculatecostsavingsforelectricityusage.
*Autumn=billingperiodsbeginninginMarch–May;winter=billingperiodsbeginninginJune–August
68 OutreachEnergyandWaterEfficiencyProgram-Casestudyreport
Case study 10Communitywelfareorganisation:BelconnenCommunityService
Serviceprovider:CoolPlanet
Background information from Energy Efficiency Officer
Category Clientwouldbenefitfromanassessment,educationandbasicretrofit,suchascurtains,blindsanddraughtsealing
Household occupants Threetenantswithmoderatetoprofounddisabilities;1–2staffon24/7,andothercasualstaffthroughouttheday
Financial circumstance AlltenantsondisabilitysupportpensionType of residence ACTHousing,single-storeybrick-veneerfour-bedroomnewhome;sideofhouseis
northfacing,butthereisalargehomenextdoor,andaverandablocksmostofsun.Products to be replaced Monitorsplacedonsecondrefrigeratorandwashingmachine.(Appliancesmay
bereplacedbutarerelativelynew.)EarthSmartpowerboard,electricthrowandoutdoorclotheslinetobeprovided.ClotheslinependingapprovalfromEnvironmentandSustainableDevelopmentDirectorate.
Draught sealing required? Inadequateinsulation;contractorhascheckedandwillupgradeinsulation.Client concerns Concernsraisedaboutthehighcostofenergybills.Thefamilyoftheclientsissure
thatenergyusecanbedecreased.Thereisgasductedheatingthroughoutthehome.Itisdifficulttochangetheheatingsituationbecausethetenantshavevaryingdegreesofphysicaldisability.Block-outcurtainsareonmostofthewindows,buttherearenopelmets.Thewashingmachineisusedseveraltimesperday.Staffandfamilyareveryopentofurthereducationandretrofitting,andhaveagreedtobepartofacasestudy.
Date of referral 4May2012
The house, its timeline of retrofitting activities and thermal performanceFour-bedroom,brick-veneerhousebuiltin2009.Excellentsolaraccesstomainlivingareas.
Thermal performance simulation (energy efficiency rating) of proposed retrofit measures Thermalperformancesimulationwasnotconductedforcasestudy10because,whenthehousewasbuiltin2009,thedesignwasrequiredtomeetminimum6-starstandards.Thecertifiedenergyratedplanswereprovidedandshowedthatthetotalpredictedheatingandcoolingloadforthehousewasjust146MJ/m2.
Aerial view ↑North (at 45-degree angle)
Timeline of testing and retrofitting activities
Date Action
15May Temperatureandenergy-usedataloggersinstalled
21May Education
31May Airleakageassessment
18June Draught-proofingandcurtaininstallation
13July Follow-upairleakage,anddatacollection
environment.act.gov.au 69
Air leakage resultsTheinternalbuildingenvelopeofthisrecentlybuilthousewasrelativelywellsealedtobeginwith.
Theareaswhereleakagewasoccurringincluded:
• aroundslidingdoorframes
• exhaustventsinthebathroomandlaundry
• openventilationbehindrefrigeratorandoven
• smallgapsinandaroundwindowsanddoorframes
• ceiling-mountedair-conditioningvents.
Thelaundrydoorwassealedusingbrushstripping,andfoamwasusedtosealaroundthesidesoftherefrigeratortolimitaircirculationtotheareabehindtherefrigeratorwhereitismosteffective.
Significanteffortandbudgetwouldberequiredtofurthersealahouseofthissize.Itisalsounlikelytoreturnsignificantbenefits.Theenergyusageofthehousecouldbebetterreducedwithfurtherattentiontoinsulation,heatingmanagementandenergy-efficientwhitegoods.
Result from air leakage testing
Pre-retrofit Post-retrofit Difference
Airchangesperhourat50Pa 9.99 9.60 –4%
Effectiveleakageareaat4Pa(equivalentopensquarewindow)
48cmx48cm 47cmx47cm 10cmx10cm
Note: Apressuredifferenceof4Pabetweeninsideandoutsideisclosetothenormalpressuredifferentialexperiencedinthehomeoncold,windyCanberradays.
Energy billsThisisnotatypicalhouseintermsofenergyusebecausetheresidentsrequireconstantassistance.Thereareusually4–7peopleinthehouseatanyonetime.
Electricity usage
Energy use 2011 (kWh/day) Energy use 2012 (kWh/day) Difference
Autumn* 36 32 –10%
Winter* 25 26 +4%
Gas usage
Energy use 2011 (kWh/day) Energy use (kWh/day) Difference
Autumn* 128 114 –11%
Winter* 65 84 +30%
Total energy, greenhouse gas and cost savings
Energy saving (kWh) CO2-e saving (kg)a Cost saving ($)b
Autumn* 1602 582.57 149.59
Winter* –1817 –412.76 –145.71
a Scope2+Scope3emissionfactorforelectricityis1.06kgCO2-e/kWh(source:AustralianGovernmentDepartmentofClimateChangeandEnergyEfficiency,National Greenhouse Gas Accounts factors,July2012).
b 2012rateisusedtocalculatecostsavingsforgasusage.
*Autumn=billingperiodsbeginninginMarch–May;winter=billingperiodsbeginninginJune–August
70 OutreachEnergyandWaterEfficiencyProgram-Casestudyreport
Case study 11Communitywelfareorganisation:NorthsideCommunityService
Serviceprovider:C&JGroup
Background information from Energy Efficiency Officer
Category Clientwouldbenefitfromanassessment,educationandbasicretrofit,suchascurtains,blindsanddraughtsealing
Household occupants 2
Financial circumstance Disabilitysupportpension
Type of residence Homeowner
Products to be replaced –
Draught sealing required? Yes.Gapsindoorsandwindows,vents,down-lights.
Client concerns Clientgetsverycoldinwinter.Possibleupgradeofinsulation.Windowcoveringsareinadequateinpartsofthepropertywhereheatislost.
Date of referral 27April2012
The house, its thermal performance and timeline of retrofitting activitiesFour-bedroom,brick-veneerhouse.
Thermalperformancesimulation(energy efficiencyrating)ofproposedretrofitmeasures Thermalperformancesimulationwasnotconductedforcasestudy11becauseoftimeconstraints.
Aerial view ↑North
Timeline of testing and retrofitting activities
Date Action
9May Temperatureandenergy-usedataloggersinstalled
25May Airleakageassessment
6June Education
8June Draught-proofing
19July Follow-upairleakage,anddatacollection
23August Curtainandpelmetinstalled
environment.act.gov.au 71
Air leakage resultsThethermalperformanceofthehousewassignificantlycompromisedbyarangeofpenetrationsandopeningsinthebuildingenvelope,including:
• severalunsealedexhaustfansinkitchen,toiletandbathroom
• permanentventsinthewallsinmostrooms
• recessedlightinginceiling
• unsealed‘Tastic’inbathroom
• leakagearounddoorsandsurroundingarchitraveinfrontextensionroom,aswellasbetweenthebrickwallandceilinggyprock
• leakagearoundandthroughwindowframes
• leakagebetweenwindowarchitravesandgyprock
• permanentopeningsintoiletdoor
• leakagethroughslidingdooropeningsinbathroom
• gapsaroundceilingvents
• gapsthroughandarounddoorways
• gapsaroundslidingdoorinbathroom.
Measurestoreduceairleakageincluded:
• placingDraftStoppas®overthebathroomandkitchenfans
• sealingthepermanentwallvents(therecessedlightingwasunabletobesealedasthelightfittingsweretoolarge)
• siliconingceilingvents,wherepossible
• sealingdoorwayswithsealingtapeanddoorstops.
Theretrofitmadeasmalldifferencebut,giventhesizeofthehouseandthenumberofproblems,itwouldgreatlybenefitfromfurthertimeandbudgetbeingallocatedtoreducefurtherairleakage,particularlythroughthebathroomviatheunsealedTastic.Therecessedlightsshouldberemoved,andtheevaporativecoolingsystemshouldhaveventsplacedoverthesystembecauseitisparticularlyleaky.
Result from air leakage testing
Pre-retrofit Post-retrofit Difference
Airchangesperhourat50Pa 20.24 17.14 –15%
Effectiveleakageareaat4Pa(equivalentopensquarewindow)
48cmx48cm 46cmx46cm 14cmx14cm
Note: Apressuredifferenceof4Pabetweeninsideandoutsideisclosetothenormalpressuredifferentialexperiencedinthehomeoncold,windyCanberradays.
72 OutreachEnergyandWaterEfficiencyProgram-Casestudyreport
Temperature and electricity useThehouseusescentralgasheatingtomaintainverycomfortabletemperaturesrelativetoexternaltemperatures.Thepoorhealthoftheresidentsandthefactthattheyarehomealldayincreasestheirenergyrequirements.
Electricity use and temperature data in case study 11
Tem
pera
ture
(0 C)
Electricity use (kWh)
40 45
30 30
35 35
25 25
20 20
15 15
10 10
5 5
0 0
Kitchen temperatureExternal temperatureLounge temperatureElectricity use
1 JU
NE
1 JU
LY
Electricity use
Leakagetest
Draughtsealing
Education Postretrofit
test
Energy bills
Electricity usage
Energy use 2011 (kWh/day) Energy use 2012 (kWh/day) Difference
Autumn* 29 22 –25%
Winter* 28 24 –16%
Gas usage
Energy use 2011 (kWh/day) Energy use 2012 (kWh/day) Difference
Autumn* 121 136 +12%
Winter* 142 133 –6%
Electricity + gas usage
Energy use 2011 (kWh/day) Energy use 2012 (kWh/day) Difference
Autumn* 150 158 +5%
Winter* 170 157 –8%
Total energy, greenhouse gas and cost savings
Energy saving (kWh) CO2-e saving (kg)a Cost saving ($)b
Autumn* –704 448.19 –12.08
Winter* 1237 595.07 130.81a Scope2+Scope3emissionfactorforelectricityis1.06kgCO2-e/kWh.Emissionfactorfornaturalgasis51.33kgCO2-e/GJ(source:
AustralianGovernmentDepartmentofClimateChangeandEnergyEfficiency,National Greenhouse Gas Accounts factors,July2012).b Costsavingsforgasusagecalculatedusing2.113centspermegajoule
*Autumn=billingperiodsbeginninginMarch–May;winter=billingperiodsbeginninginJune–August