Outreach Energy and Water Efficiency Program · to Housing ACT for draught sealing and ceiling insulation top-ups. ... 8 Outreach Energy and Water Efficiency Program - Case study

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

2 OutreachEnergyandWaterEfficiencyProgram-Casestudyreport

Further informationForfurtherinformationonthisreport,pleasecontact:

EnvironmentandSustainableDevelopmentDirectorate

Telephone:132281

Facsimile:62072316

Website:www.environment.act.gov.au/water

©AustralianCapitalTerritory,Canberra2013

Thisworkiscopyright.ApartfromanyuseaspermittedundertheCopyright Act 1968,nopartmaybereproducedwithoutthewrittenpermissionfromCustomerServicesandInformation,EnvironmentandSustainableDevelopmentDirectorate(ESDD),ACTGovernment,GPOBox158,CanberraCityACT2601

Disclaimer:ESDDdoesnotguaranteethatthedataisfreefromerrors.

PublishedbytheACTGovernmentEnvironmentandSustainableDevelopmentDirectorate

AcknowledgementsTheOutreachEnergyandWaterEfficiencyProgramforthesecasestudieswasdeliveredbyenergyefficiencyofficersonbehalfofthefollowingcommunitywelfareorganisations:

BelconnenCommunityService

Communities@Work

NorthsideCommunityService

SocietyofStVincentdePaul

YWCAofCanberra.

AssessorsandretrofittersfromC&JGroupandCoolPlanetprovidedenergyandwaterefficiencyassessments,educationandretrofittingfortheOutreachProgram.StafffromHousingACTcoordinatedtheenergyefficiencyimprovementsonHousingACTproperties.

Prepared byScinergy:theScienceofEnergyEfficiency

EditedbyBiotextPtyLtd,Canberra

The ACT Government is committed to making information, services, events and venues accessible to as many people as possible. If you have difficulty reading a standard printed document and would like to receive this publication on an alternative format – such as large print or audio – please telephone 02 6207 7307.

If English is not your first language and you require the translating and interpreting service please telephone 131 450. If you are deaf or hearing impaired and require the TTY typewriter service please telephone 02 6207 2622.

http://www.environment.act.gov.au/water


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.



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.



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.


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.

http://apps1.eere.energy.gov/buildings/publications/pdfs/building_america/26446.pdf

http://apps1.eere.energy.gov/buildings/publications/pdfs/building_america/26446.pdf


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.



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.


Retired,old-agepension

Participanthaslargewinterheatingbills.In2011,participanthadhealthconcerns,andasecondpersonwaslivinginthehome.Househaselectricheatinginslab.Electricityonly.

4 3 HousingACT

Single-parentpension

Motherofyoungchildrenwithrespiratoryhealthconcerns.Asecondadultmovedinduringthecasestudymonitoring.Extremelycoldhouse,withlimitedsolarheatgainbecauseofhouseorientation,andverydraughty.Electricresistanceheating.Electricityonly.



Insulationwasthinandpatchy,andthehousehadpermanentventsineveryroom.Gasheatinginlivingareas.Electricreverse-cyclesystemsinbedrooms.Electricityandgas.


Case study number

Number of occupants

Type of residence

Financial circumstances

Description

6 2 HousingACT

Singlemotherwithpart-timework

Houseverycoldinwinterandveryhotinsummer.Electricresistancewall-mountedheater.Electricityonly.


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


Threetenantswithdisabilities;1-2staffonsite24hoursperdaywithupto7peoplepresentatanyonetime.Tenantsdonothavedirectcontrolofenergyuseandrelyonstaffmembersforassistance.Gasheating.Electricityandgas.



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.

http://www.nathers.gov.au

http://www.solarlogic.com.au/bers-pro


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



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%.


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.


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


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.

http://www.bpi.org/documents/Yellow_Sheet.pdf


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.


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

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

Image 6. 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


Image 7 Electricity use and temperature data in case study 6Te

mpe

ratu

re (0 C)


50 50

40 40

30 30

20 20

10 10

0 0

Bedroom temperature External temperature Living room temperature

Electricity use

1 M

AY

1 JU

NELeakage

testingCeiling

insulationinstalled

Draught sealing 2

Postretrofit test

Educationdraught sealing 1

Electricity use

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


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).

http://www.bom.gov.au/climate/current/season/act/archive/201208.summary.shtml


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


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


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


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.


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.



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.


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.


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.



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


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


• 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


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.


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


Autumn* 7 13 +85%

Winter* 5 13 +160%

Electricity + gas usage


Autumn* 37 30 –19%

Winter* 45 35 –22%

*Autumn=billingperiodsbeginninginMarch–May;winter=billingperiodsbeginninginJune–August


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



Case study 2Communitywelfareorganisation:BelconnenCommunityService

Serviceprovider:CoolPlanet




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


Date Action

2April Temperatureandenergy-usedataloggersinstalled

16April Airleakageassessmentandthermographicinspection

20April Education

1May Draught-proofingexternalandinternaldoors

18May Curtainsandpelmetsinstalled

18May Post-retrofittestandcollectionoftemperatureandenergy-usedata

20June Furtherdraught-proofingcavitydoorsliderandwall–ceilingjoins




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


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.



Airchangesperhourat50Pa 13.3 11.8 –11%





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


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


Energy bills

Electricity usage


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.



Autumn* 294 312.08 44.60

Winter* 550 583.53 94.71


b Costsavingsforelectricitycalculatedusing15.15(autumn)and17.21(winter)centsperkilowatthour








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


Date Action18April Temperatureandenergy-usedataloggersinstalled20May Airleakageassessmentandthermographicinspection19May Education10June Draught-proofingexternalandinternaldoors22June Curtainsandpelmetsinstalled



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


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



Airchangesperhourat50Pa 7.72 – –

Notes: Casestudy3wasnotretestedforairleakageafterdraughtsealingbecauseitwasalreadybelowthetargetlevelof10airchangesperhourat50Pa,andfundswerebetterspentonhomesthatwerefurtherfromthistarget.




Old 2.1 766 812

New 0.92 329 349 –57%



Temperature and electricity useEnergyconsumptionclearlydroppedfollowingtheeducationsessionandexplanationoftheenergy-usemonitor.


Educationre in-slabheating

Leakagetest

Tem

pera

ture

(0 C)


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


Autumn* 44 18 –60%

Winter* 65 18 –73%


Actualenergyconsumptiondatafromquarterlybillsdemonstratea73%reductioninoverallhouseholdenergyuse(i.e.notjustheatingandcoolingbutalsoappliances,lighting,hotwaterheating,etc.)betweenwinter2011andwinter2012.Thissuggeststhateducationandassociatedbehaviourchangecouldaccountformostofthereductioninenergyconsumption.In2011,theclienthadbeenunwellandhadanotherfamilymemberstayinginthehouse.Asaresult,theinefficientelectricslabheatingsystemhadbeenusedthroughoutthewholehouseratherthanbeingzonedforuseintheendofthehouseoccupiedbytheresidentonhisown.



Autumn* 2395 2538.76 326.87

Winter* 4269 4525.82 685.84


b Peak/off-peakrateisusedtocalculatecostsavingsforelectricityusage.



Case study 4Communitywelfareorganisation:SocietyofStVincentdePaul



Category Homeisdraughty,withnocurtainsorblinds,andtheclienteitherhashighbillsorislivinginimpoverishedconditions.Clientwouldbenefitgreatlyfromanassessment,educationandbasicretrofit.


Financial circumstance Centrelink—singleparent

Type of residence ACTHousing

Products to be replaced Refrigeratorandwashingmachinealreadyreplaced


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



Date Action


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



Star rating

Heating (MJ/m2)

Cooling (MJ/m2)

Total (MJ/m2)


Actual cost ($)


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


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.







Air Leakage points

Unsealed exhaust fan in kitchen Ceiling vent in bedroom Between architrave and gyprock


InsulationThermalimagingshowedthatthewallswereuninsulated.Ceilinginsulation,althoughpresent,appearedtobethinandpatchyinsomeareas.Onamild,sunnydayinMarch,thewallsofthemasterbedroomwereatapproximately13°C;theceilingwasat14.5°C.


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.


Tem

pera

ture

(0 C)


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


Energy bills

Electricity usage


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.



Autumn* 1056 1119.80 133.41

Winter* 2780 2947.20 418.30


b Peak/off-peakrateisusedtocalculatecostsavingsforelectricityusage.



Case study 5Communitywelfareorganisation:NorthsideCommunityService







Products to be replaced Washingmachine,refrigeratorandfreezer


Couldbenefitfrompelmets.Sensorlightstaysonallthetime.Gasheatingsettingsarefaulty.Insulationinceilingisalmostnon-existent,andthereisnoinsulationinwalls.


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



Date Action

9May Temperatureandenergy-usedataloggersinstalled

21May Education


29May Draught-proofing

31May Top-upinsulation,curtainsandpelmetsinstalled

17June Post-retrofittestandcollectionoftemperatureandenergy-usedata




Star rating

Heating (MJ/m2)

Cooling (MJ/m2)

Total (MJ/m2)


Actual cost ($)


Startingconditions:•CeilingsR2,walls/floorsR0•Multipleceilingvents(eachroom)

•Openexhaustfaninkitchen•Lightcurtains/blinds

2.8 396 34 430


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


• arounddoorsandwindowframes

• aroundceilingandwallpenetrations,suchasroofaccessholeandwall-mountedair-conditioningsystems.


Therateofairleakagewasreducedby41%byinstallingaDraftStoppa®inthekitchen,sealingoffunnecessaryceilingventsandsealingaroundexternaldoors.

Thepermanentventsandotherpenetrationsintheceilingseriouslycompromisedthepotentialofthehousetostaywarm.Heatedairfromwithinthehomewasrisingandrapidlyescapingintotheroofspaceviatheholesintheceiling.

Thereductioninairleakageachievedinthishome,byfocusingmainlyontheholesintheceiling,isequivalenttoclosinga31cmx31cmwindowinthebuildingenvelope.







Air Leakage points

Gap through architrave and around door

One of many ceiling vents Leakage around roof access hole

InsulationTheroofhadrockwoolinsulationthatwasthinandunevenlyinstalled.Thiscausedsignificantfluctuationsinceilingtemperaturethroughoutthehouse.Thermalimagingindicatedthatnowallinsulationwaspresent(asexpectedinahouseofthisage).


Living area, no wall insulation Lounge area, patchy ceiling insulation


Temperature and electricity usePassiveventilationthroughoutthishomeviamultipleceilingventsandotherunsealedpenetrationsisresponsibleforthelargefluctuationsininternaltemperature.Datafromthethermochronshighlightthefollowing:

• Beforetheretrofit,internaltemperatureswereregularlyonly8°Cwarmerthantheexternaltemperature.Aftertheretrofit,theywereregularly10°Cwarmerthantheexternaltemperature.

• Thekitchen/diningareaiswarmerafterretrofittingandreachesamaximumtemperatureabove20°Cmoreoften.

• Followingtheretrofit,thehomemaintainshighertemperaturesandexperienceslessfluctuationintemperature,butenergyusehasdecreased.


Tem

pera

ture

(0 C)


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


Autumn 19 22 +14%

Winter 18 19 +5%

Gas usage


Autumn 112 98 –12.5%

Winter 120 87 –27.5%



Autumn 131 120 –8%

Winter 138 106 –23%




Actualenergyconsumptiondatafromquarterlybillsdemonstratea23%reductioninoverallhouseholdenergyuse(i.e.notjustheatingandcoolingbutalsoappliances,lighting,hotwaterheating,etc.)betweenwinter2011andwinter2012.Thissuggeststhateducationandassociatedbehaviouralchangecouldaccountfortheextrareductioninenergyconsumption.



Autumn* 1038 –14.84 61.18

Winter* 2921 467.85 213.82


b Costsavingsforgasusagecalculatedusing2.113centspermegajoule








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.


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



Date Action



6June Ceilinginsulationinstalled

11June Draught-proofing

12June Education

20June Draught-proofingbathroom,newextractorfaninstalled,andinvestigationofdampinchild’sbedroom

22June Post-retrofittest,andcollectionoftemperatureandenergy-usedata



Star rating

Heating (MJ/m2)

Cooling (MJ/m2)

Total (MJ/m2)


Actual cost ($)


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.


Therateofairleakagewasreducedby75%afterdraughtsealingtheventedskylightsandaroundtheexternaldoors.Thereductioninairleakageachievedinthishome,byfocusingmainlyontheholesintheceiling,isequivalenttoclosinga25cmx25cmwindowinthebuildingenvelope.







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).


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


feelingofwarmthinherhomeornotbeingfullyawarethatheatingisstillbeingusedandtheneedtolowerthethermostat.Thishighlightstheneedforfollow-upeducationsessionsfollowingretrofittingmeasuressothatclientsareawareofhowtheycanreducetheirenergyuse.


Tem

pera

ture

(0 C)


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


Autumn* 23 14 –40%

Winter* 67 44 –35%


Actualenergyconsumptiondatafromquarterlybillsdemonstratea35%reductioninoverallhouseholdenergyuse(i.e.notjustheatingandcoolingbutalsoappliances,lighting,hotwaterheating,etc.)betweenwinter2011andwinter2012.Thissuggeststhateducationandassociatedbehaviouralchangecouldaccountfortheextrareductioninenergyconsumption.



Autumn* 845 895.79 128.03

Winter* 2103 2229.09 345.65


b Actualratesforautumnandwinter2012wereusedtocalculatethecostsavingsforelectricityusage.



Case study 7Communitywelfareorganisation:Communities@Work





Financial circumstance Low-incomehousehold


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


Date Action


7June Airleakageassessmentandthermographicinspection

12July Draught-proofing

24July Education

27July Post-retrofittestandcollectionoftemperatureandenergy-usedata

July–September Furtherdraught-proofingcavitydoorsliderandwall–ceilingjoins(exactdateunclear)

19September Curtainsandpelmetsinstalled




Star rating

Heating (MJ/m2)

Cooling (MJ/m2)

Total (MJ/m2)


Actual cost ($)


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


• permanentopeningabovefridge

• unsealedopen-shaftskylight

• cavityslidingdoor

• wall-mountedpanelheater

• roofaccesshole.


Airleakagewasreducedby:

• sealingbetweentheinternalbrickwallandadjoiningwallsandcornicing

• installationofaDraftStoppa®abovethetoiletfan

• sealingarounddoorframesandcatches

• sealingaroundarchitravesanddoorframes

• sealingtheskylightinthebathroom.







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.



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


Autumn* 7 8 14%

Winter* 9 15 62%

Gas usage


Autumn* 19 16 –16%

Winter* 43 36 –16%



Autumn* 28 24 –14%

Winter* 52 51 –2%


Energy saving (kWh) CO2-e saving (kg)a Cost savings ($)b

Autumn* 176 –52.25 6.1

Winter* 117 –434.05 –38.47


b Costsavingsforgasusagecalculatedusing2.113centspermegajoule*Autumn=billingperiodsbeginninginMarch–May;winter=billingperiodsbeginninginJune–August


Case study 8Communitywelfareorganisation:Communities@work





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


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


Date Action


7June Airleakageassessment

7July Draught-proofing

12July Draught-proofingofbathroomexhaustfan/skylight

27July Post-retrofittestandcollectionoftemperatureandenergy-usedata

5December Curtainsandpelmetsinstalled




Star rating

Heating (MJ/m2)

Cooling (MJ/m2)

Total (MJ/m2)


Actual cost ($)


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.










Old 2.3 839 889

New 0.91 334 354 –61%



Energy bills

Electricity usage


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.



Autumn* 291 308.19 44.05

Winter* 804 852.23 138.62


b Autumnandwinter2012rateisusedtocalculatecostsavingsforelectricityusage.



Case study 9Communitywelfareorganisation:YWCAofCanberra





Financial circumstance Centrelink

Type of residence ACTHousing

Products to be replaced Refrigerator


RecommendedtoclienttocontactSpotless.Draughtsealingrequiredandinsulationcheck.Houselooksdraughty.

Client concerns Draughtyhouse,whichgetshotandcold.Curtainsexistbutaredirty;theclientisconcernedaboutprivacy,becauselivingroomwindowsfaceontoamajorroad.Possiblycouldalsoimprovethecurtaincurrentlyusedtozonethelivingarea.


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


Date Action


11May Education

11May Airleakageassessment

25June Curtains,pelmets,lightinganddraughtsealingcompleted

13July Finalcollectionofdata


Air leakage resultsApressuredifferenceof4Pabetweeninsideandoutsideisclosetothenormalpressuredifferentialexperiencedinthehomeoncold,windyCanberradays.

Theoverallleakagerateofthisbuildingwaslowcomparedwithothercasestudyhousesbecausetheexternalwallandroofareawasrelativelysmallasaresultofitsthree-storey,multi-unitconstruction.Becausetheairleakageratewasalreadybelowourtargetof10airchangesperhourat50Pa,anditwasdifficulttotestinaconfinedentrancewayinthethree-storeyapartment,apost-retrofittestwasnotconducted.However,thereweresignificantleaksthatcouldbesealed,including:


• permanentopeningsinwallsabovewindowsinkitchen,bathroomandlivingareas

• plumbingandelectricalpenetrationsbehindkitchenjoinery

• arounddoorsandsurroundingarchitrave,particularlyinthestaircase

• aroundoldwall-mountedheater

• betweenwindowsandgyprock,walljunctionsandroofbeams.

Measurestoaddresssomeoftheseleaksincluded:

• usingperspextosealaroundplumbingpenetrationsunderthekitchensink(althoughtherewerestillnoticeableleaksaroundthesepenetrations)

• addingsomesealantaroundarchitraves

• sealingvariousdoors.

Themainlivingareasdownstairshadapermanentopendoorframe,allowinganywarmairtoriseupthestairsandventouttheupstairspermanentopenings.

Therooflackedinsulation,andhenceanywarmaircontainedwasquicklycooledbythesurroundingcoldwalls.



Airchangesperhourat50Pa 9.4 – –


25cm×25cm – –

Notes: Casestudy9wasnotretestedforairleakageafterretrofittingbecauseitwasalreadybelowthetargetlevelof10airchangesperhourat50Pa,andfundswerebetterspentonhomesthatwerefurtherfromthistarget.


Temperature and electricity useThisapartmentusesaveryinefficientheatingsystemtokeepinternaltemperatures10°Chigherthanexternaltemperatures.


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


Autumn* 27.3 23 –16%

Winter* 146 89 –39%



Autumn* 399 422.84 60.43

Winter* 5185 5496.05 928.10


b Variableratesareusedtocalculatecostsavingsforelectricityusage.







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.


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)


Date Action


21May Education


18June Draught-proofingandcurtaininstallation

13July Follow-upairleakage,anddatacollection


Air leakage resultsTheinternalbuildingenvelopeofthisrecentlybuilthousewasrelativelywellsealedtobeginwith.

Theareaswhereleakagewasoccurringincluded:

• aroundslidingdoorframes

• exhaustventsinthebathroomandlaundry

• openventilationbehindrefrigeratorandoven

• smallgapsinandaroundwindowsanddoorframes

• ceiling-mountedair-conditioningvents.

Thelaundrydoorwassealedusingbrushstripping,andfoamwasusedtosealaroundthesidesoftherefrigeratortolimitaircirculationtotheareabehindtherefrigeratorwhereitismosteffective.

Significanteffortandbudgetwouldberequiredtofurthersealahouseofthissize.Itisalsounlikelytoreturnsignificantbenefits.Theenergyusageofthehousecouldbebetterreducedwithfurtherattentiontoinsulation,heatingmanagementandenergy-efficientwhitegoods.







Energy billsThisisnotatypicalhouseintermsofenergyusebecausetheresidentsrequireconstantassistance.Thereareusually4–7peopleinthehouseatanyonetime.

Electricity usage


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%



Autumn* 1602 582.57 149.59

Winter* –1817 –412.76 –145.71


b 2012rateisusedtocalculatecostsavingsforgasusage.



Case study 11Communitywelfareorganisation:NorthsideCommunityService






Type of residence Homeowner

Products to be replaced –

Draught sealing required? Yes.Gapsindoorsandwindows,vents,down-lights.

Client concerns Clientgetsverycoldinwinter.Possibleupgradeofinsulation.Windowcoveringsareinadequateinpartsofthepropertywhereheatislost.


The house, its thermal performance and timeline of retrofitting activitiesFour-bedroom,brick-veneerhouse.

Thermalperformancesimulation(energy efficiencyrating)ofproposedretrofitmeasures Thermalperformancesimulationwasnotconductedforcasestudy11becauseoftimeconstraints.

Aerial view ↑North


Date Action



6June Education

8June Draught-proofing

19July Follow-upairleakage,anddatacollection

23August Curtainandpelmetinstalled


Air leakage resultsThethermalperformanceofthehousewassignificantlycompromisedbyarangeofpenetrationsandopeningsinthebuildingenvelope,including:

• severalunsealedexhaustfansinkitchen,toiletandbathroom

• permanentventsinthewallsinmostrooms

• recessedlightinginceiling


• leakagearounddoorsandsurroundingarchitraveinfrontextensionroom,aswellasbetweenthebrickwallandceilinggyprock

• leakagearoundandthroughwindowframes

• leakagebetweenwindowarchitravesandgyprock

• permanentopeningsintoiletdoor

• leakagethroughslidingdooropeningsinbathroom

• gapsaroundceilingvents

• gapsthroughandarounddoorways

• gapsaroundslidingdoorinbathroom.

Measurestoreduceairleakageincluded:

• placingDraftStoppas®overthebathroomandkitchenfans

• sealingthepermanentwallvents(therecessedlightingwasunabletobesealedasthelightfittingsweretoolarge)

• siliconingceilingvents,wherepossible

• sealingdoorwayswithsealingtapeanddoorstops.

Theretrofitmadeasmalldifferencebut,giventhesizeofthehouseandthenumberofproblems,itwouldgreatlybenefitfromfurthertimeandbudgetbeingallocatedtoreducefurtherairleakage,particularlythroughthebathroomviatheunsealedTastic.Therecessedlightsshouldberemoved,andtheevaporativecoolingsystemshouldhaveventsplacedoverthesystembecauseitisparticularlyleaky.








Temperature and electricity useThehouseusescentralgasheatingtomaintainverycomfortabletemperaturesrelativetoexternaltemperatures.Thepoorhealthoftheresidentsandthefactthattheyarehomealldayincreasestheirenergyrequirements.


Tem

pera

ture

(0 C)


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


Autumn* 29 22 –25%

Winter* 28 24 –16%

Gas usage


Autumn* 121 136 +12%

Winter* 142 133 –6%



Autumn* 150 158 +5%

Winter* 170 157 –8%



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


Documents

Outreach Energy and Water Efficiency Program · to Housing ACT for draught sealing and ceiling insulation top-ups. ... 8 Outreach Energy and Water Efficiency Program - Case study