06 Building Energy Retrofits in Social Housing Dr …...• Energy retrofits can have a positive,...
Transcript of 06 Building Energy Retrofits in Social Housing Dr …...• Energy retrofits can have a positive,...
BuildingEnergyRetrofitsinSocialHousing20thAnnualBuildingScienceCamp
August2nd2016MarianneTouchie
ImageCredit:UniversityofToronto
Outline
• CharacteristicsofsocialhousingMURBs
• Driversofandapproachtoretrofit• It’snotallaboutenergy• Casestudiesandresearch
ImageCredit:UniversityofToronto
CharacteristicsofSocialHousingBuildings
• Theyareold1
• Theyuselotsofenergy2
• Theyaren’twellmaintained3
• Theyhavepoorqualityindoorenvironments4
• Therearealotofthem!5
1HarvardUniversityGraduateSchoolofDesign2003,Somerville&Mayer20032DepartmentofEnergy20113AbtAssociates20104Jacobsetal.,2007,Northridge20105https://www.ucalgary.ca/cities/files/cities/toronto-report.pdf
Meanageofmetropolitanaffordablehousing46years
19%
4%
PublicHousing
NationalAverage
Energycostrelativetoannualincome
$26Bbacklog29%ofallrentalunitsinToronto
Add vintage graph, pie chart with energy, $26B backlog, % of housing provided?
MURBEnergyUseishighlyvariableEn
ergyIntensity
(ekW
h/m2)
0
150
300
450
600
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39
LowestDecile
HighestDecile
3.4times
SampleofTorontoMURBs
MURBEnergyuse-NYC
ImageCredit:NewYorkCityMayor’sOffice2012,p14
GreatpotentialtoimproveMURBenergyperformance
ImageCredit:NewYorkCityMayor’sOffice2012,p181Brownetal.2015
18%reduction↓
↑31%reduction
RyersonStudy:57%heatingand84%coolingvariabilitybecauseofoccupants1
Whatpromptsanenergyretrofits?
• Emergencyreplacementoffailingequipment
• Anticipatingequipmentatend-of-life(tryingtoavoidemergencies!)
• Needtoreduceoperatingexpenses• Incentiveprograms
Lowesthangingfruit
• Lightingretrofits• Waterfixturereplacement(toilets,showerheads)
Imagecredits:TorontoAtmosphericFund
Caseforcomprehensiveenergyretrofitsinsocialhousing• Takeadvantageofblendedpayback• Piecemealapproachtakeslonger,moreexpensive,limitedabilityforimprovedurability
• Reducevulnerabilitytochangingutilityprices• Limitsonequipmentefficiency
EnergyEndusesintypicalU.S.MURB
Imagecredit:USEIA2008
HeatingenergyuseMon
thlyNaturalGas
Consum
pHon
(ekW
h)
0
500,000
1,000,000
1,500,000
2,000,000
MonthlyHeaHngDegreeDays(°C·day)
0 200 400 600 800
• VariableLoadComponent
•BaseLoadComponent
Imagecredit:Touchieetal.2013
DHWequipmentefficiency
Buildingenvelope+HVACequipmentefficiency
EnvelopeThermalResistance
NaturalGasHeaHngIn
tensity
(ekW
h/m²)
0
100
200
300
400
FenestraHonRaHo
20% 35% 50% 65% 80%
R²=0.6875
R²=0.4124
SingleGlazedDoubleGlazed
• Oftenlittletonoinsulation• Thermalbridgingthroughbalconyslabs
• Single-glazedwindows,sliders
Imagecredit:Touchieetal.2013,TowerRenewalGuidelines
Airleakage
• Highlyuncertain,complex,negativeimpacts• Corridorpressurizationineffective• Canadianapartmentstudy:Measured31%to81%ofdesignventilationrates1
• Significantimpactonenergyuse• InOntario,25-40%ofpeakheatingdemand1
• Vancouverstudy:69%ofspaceheatingenergytoconditionventilationairbutaslittleas13%ofthatairgottothesuites.Largepressuredifferencesacrossinteriorpartitions.21Edwards1999
2RDH2012ImageCredit:Touchie
Stack
WindMechanical
Wind
Mechanical
Stack
HVACequipment
• Manyfactorsinfluenceefficiency
• Torontostudy:Poorcorrelationbetweenefficiencyandenergyuse• Can’trelyonestimatedefficiencies(TAFstudytotherescue)
Variab
leNaturalGas
Intensity(ekW
h/m2)
0
75
150
225
300
BoilerEfficiency
60% 95%
y=-165.76x+289.89R²=0.0837
Imagecredit:TorontoAtmosphericFund;Touchieetal.2013
Stepstodesigninganenergyretrofitstrategy
• Establishbaselineperformance
• Developacalibratedmodel
• Determinepotentialsavingsandsettargets
• Evaluateretrofitoptions• Selectastrategythatmeetstargetsandbudgetconstraints
Establishyourbaselineperformance
• Buildingconditionassessmentandhistoricalenergybills
• Targetedassessmentofmajorfactorsinfluencingenergyperformance:• Assessenvelopeperformancethroughairleakagetesting,infraredimaging• Performancemonitoringofboilers,chillers,make-upairunits,pumps• Electricitysub-metering
• Lookforrecommissioningopportunities• LBNLstudy:retro-commissioningcostsapprox.$0.30/ft2,reducedenergyconsumptionby16%,paybackof1.1years1
1RockyMountainInstitute2013
Developacalibratedenergymodel
• Beawareofmodeluncertainties
AverageSuiteTem
perature
(°C)
17
20
23
25
28
1 2 3 4 5 6 7 8 9 10 11 12
TradioonalModel ActualSuiteAverage RefinedModel
HeatingSeason HeatingSeasonCoolingSeason
Imagecredits:Touchie2014
Determinepotentialandsettargets
Imagecredit:http://www.rmi.org/retrofit_depot_the_blueprint_enacting_a_deep_energy_retrofit
RockyMountainInstitute:Howmuchcouldyousaveiftherewerenoeconomicornon-technicalconstraints?
Modelandselectenergyretrofitstrategies
• Passive:Windowreplacement/overcladding,Airsealingmeasures
• Active:Equipmentreplacement/refurbishment
• Synergies?
• Considerincrementalcostofhigherperformancecomponentsandpotentialenergysavings
• Considerthecapitalcostsavingsofdownsizingequipmentifloadisreduced
Andyou’redone!
• Contracting,Construction,Commissioningandstartsavingenergy!
Savingenergyisgood,right?
• Itis!Butitshouldnotbeattheexpenseoftheindoorenvironmentalquality(IEQ)
• Buildingsareforpeople:comfortandhealthofresidentsshouldbeparamount
• Energyretrofitscanhaveapositive,neutralornegativeinfluenceonIEQ:shouldconsidertheseinfluencesearlyinthedesignstage
Occupanthealth
• Spend90%oftimeindoorsandmorethan65%timeinresidentialbuildings1,2
• Movementofodors(cooking,tobaccosmoke)isacommoncomplaintinMURBs3
• Environmentalexposuredependsonmanyfactors
1Klepeisetal.20012Leechetal.20023CMHC2003
Occupantexposureinsocialhousing
• Prevalenceofasthma2-4timeshigherinvulnerablepopulations,thanthegeneralpopulation1
• Reductioninasthmamorbidityamongchildrenwhencomparingnewsocialhousingunitstoolderbuildings1
• BostonHousingAuthority:concentrationofmultipleindoorpollutantsarehigherinlow-socioeconomichouseholds,comparedtogeneralpopulation2
1Coltonetal.20152Adamkiewiczetal.2011
Occupantexposureinsocialhousing
Occupantcomfort
• Lotsofattentioninthecommercialsector(Productivity=$$$)
• Under-heatinginsomeareas• Fuelpovertyandpoorenvelopeperformancecanleadtounder-heating1
• Chronicoverheatingevenincoldclimates• Serioushealthimplicationsofoverheating• NYC:46heatstrokedeathsin2006,mostdidnothaveworkingA/C,andmorethan80%wereexposedathome2
1A.Powers,personalcommunication2ExtremeheatawarenessandprotectivebehaviorsinNYC,2013
StudyofoverheatinginToronto’ssocialhousing
• Over50%ofresidentsreportedfeeling“TooWarm”duringsummer
• Averagesummerairtemperatureindoors27.7°C(82°F)
• Thermaldissatisfactionandbuildingheight:Stackeffect?
• Mechanicalsolutionsmaynotbetheonly/bestapproach
Increasingthreatofoverheating
• Heat-relateddeathsexpectedtodoubleovernext30years1
• Lowerincomehousingisathigherrisk:• Poorqualityhousing• Nocentralcooling• Higherlikelihoodofpre-existingillness
• Withoutcoolingmeasures,buildingsaccumulateheat1
• Montrealstudy:averageapartmenttemp4°Chigherthanoutside• NYCstudy:averageindoortemp2.8°Chigherthanoutside
1CityofTorontoStaffReport2015
ConsiderEnergyandIEQfromthestart…
Co-benefits• BetterIAQ• Betterthermalcomfort• Betterdurability
RevisedstepstodesigningE+IEQRetrofit
• Determineresidentsneeds(surveys,focusgroups)andcapabilitiesofon-sitestaff• Establishcomprehensivebaselineperformance(includingtemperatureandIAQassessments)• Developacalibratedmodel• EstablishenergysavingstargetsandgoalsforIEQimprovement• ModelsretrofitstrategiestodeterminepotentialforE+IEQimprovements• SelectstrategiesthateitherimproveorhavenoimpactonIEQ• Construction,commissioning,testing,monitoring,surveys…
Residentengagement
• Communitymeetings
• Surveys,Focusgroups• Designcharrettes• Providestatusupdates• Movevulnerableresidentsoffsite
• Considerhowinformationispresented
Establishcomprehensiveperformancebaseline
• Consider• shorttermtemperaturemonitoringduringsummer/winter• Indoorairqualitymonitoring• Airtightnesstesting• Airflowmeasurements
Establishtargets
• Energyreductiontarget• Reductioninairleakage?• Bettertemperaturecontrol?
• Lowerpollutantlevels?
ChooseretrofitstrategiesforE+IEQbenefits
• EPA:HealthyIndoorEnvironmentalProtocolsforHomeEnergyUpgrades1
• EPIQR:Energyperformanceindoorenvironmentalqualityretrofit
• Norisetal.2013:points-basedapproachtoscorepotentialretrofitmeasuresonenergyandIEQperformanceperdollarvaluemeasure
1https://www.epa.gov/sites/production/files/2014-12/documents/epa_retrofit_protocols.pdf)
Norisetal.2013
Norisetal.2013
• 16low-incomeapartments
• Suite-basedretrofits• Pre-andpost-retrofitmonitoring
• Occupantsurveys• IEQparametersappearedtoimprovewithcontinuousbalancedventilation
SwedishPublicHousingRetrofit
• Linköping,Sweden(avgannualoutdoortemp6.9°C)
• Sixmid-rise1970’sapartmentbuildings,oneretrofitted• Overcladding,windowreplacement• in-suitecontrolofheatingsystem• Heatrecovery
Imagecredit:Luietal.2015
SwedishPublicHousingRetrofit
• Monitoring• TempandRH• Suiteelectricityuse• Heatingenergy(retrofitonly)
• ModelingwithIDAICE• Calibratedtotempandspaceheating
• Surveys
Imagecredit:Luietal.2015
Non-retrofitted
Retrofitted
AirQuality
Imagecredit:Luietal.2015
IndoorTemperature
Noise HealthIssues
SwedishPublicHousingRetrofit
MoresatisfiedwithIEQand39%reductioninspaceheatingenergy
WilmcoteHouseRetrofit
• 1968CouncilHousing,PortsmouthUK
• 100homes,mostly3bedroomunits
• Concretepanels,25mminsulation,
• Electricheat• Widespreadfuelpoverty
• Thermalcomfortissues
Imagecredit:http://www.building.co.uk/wilmcote-house-thermal-vision/5077130.article
WilmcoteHouseRetrofit
• Semi-structuredquestionnaires,interviewsbefore,duringandafter
• Meterreadings
• Whattheresidents’say:• “thewindowsarerubbish.”• “theheatersarerubbish”• “Ihadlikelittlemushroomsgrowingonthewindow…intheinside”
• “Therentis₤430amonth…sotheenergycostishalftherent”
A.Belotti,PersonalCommunicationImagecredit:http://www.building.co.uk/wilmcote-house-thermal-vision/5077130.article
WilmcoteHouseRetrofit
• R43Overcladding,newtripleglazedwindows• Measurestoimproveairtightness
• Heatrecoveryventilatorsineachapartment
Imagecredit:http://www.building.co.uk/wilmcote-house-thermal-vision/5077130.article
BelmontRetrofit
• BelmontCondominium(Notsocialhousing)
• 13-storey,37suites• Impactofover-claddingandwindowreplacementonairtightness
• Comprehensiveassessmentofairflow• PFTgastestingforinterzoneairflow• AirflowmeasurementsatMAUandcorridor• Airtightnessofenclosureandbetweensuites
BelmontRetrofit
• Overandunderventilation• HRVs?Compartmentalization?
ImageCredit:RickettsandFinch
CompartmentalizationStudy
• ModelingBelmontinEnergyPlustoexploretheenergyimpactofcompartmentalization
• Preliminaryresultsarean80%reductioninMAUnaturalgasconsumption
TorontoSocialHousingRetrofitStudy
• 3sites,7buildings,74suites• Pre-andpost-retrofit• in-suitemonitoring:
• Long-termcontinuousmonitoringoftemp,RH,MRT,CO2
• Short-termmonitoringofRadon,FormaldehydeandPMsampling
• Boilerefficiencymonitoring• Residentsurveys
MeasurestoimproveE+IEQ
• Passive→Reducedemand• Over-cladding,windowreplacement,airsealing
• Active→mechanicalventilation• Balanced,heatrecovery• Improveefficiency
• Controlstrategies• Demand-based
ImageCredit:RDH2012
Whydon’twejustdoit?
• Needagoaltoworktowards• Split/noincentive• Capacityconstraintsatthepublichousingauthority• Funding:• Otherprioritiesforavailablefunding• Separatecapitalandoperatingbudgets• Lackofawarenessaboutfundingprograms
• Inappropriateuseofenergymodeling
• Previousbadexperience
Referencesolutionstohurdlesreportwherenecessary
Onthehorizon
• Effectsofclimatechangeovertheservicelifeofthebuilding
• Energyandcarbonpricing• Energyreporting• Valuinghealthandcomfortimpactsofbuildingretrofits
Referenceshttp://blog.rmi.org/blog_2013_08_19_affordable_housing_with_unaffordable_energy_bills
RockyMountainInstitute–SolutionstoHurdlesreport
HarvardUniversityGraduateSchoolofDesign2003
Somerville&Mayer2003
DepartmentofEnergy(2011)."BuildingEnergyDataBook“;U.S.HUD’sPublicHousingProgram.Available:http://www.hud.gov/renting/phprog.cfm.Accessed12/28/2007.)
AbtAssociates2010.
JacobsDE,KellyT,SobolewskiJ.Linkingpublichealth,housing,andindoorenvironmentalpolicy:successesandchallengesatlocalandfederalagenciesintheUnitedStates.EnvironHealthPerspect2007;115:976e82. [3]NorthridgeJ,RamirezOF,StingoneJA,ClaudioL.Theroleofhousingtypeandhousingqualityinurbanchildrenwithasthma.JUrbanHealth2010;87:211e24.
https://www.ucalgary.ca/cities/files/cities/toronto-report.pdf
NewYorkCityMayor’sOffice,NewYorkCityLocalLaw84Bench-markingReport,2012,http://www.nyc.gov/html/gbee/downloads/pdf/nycll84benchmarkingreport2012.pdf–pg14
Touchie,M.F.,Binkley,C,Pressnail,K.D.“CorrelatingEnergyConsumptionwithMulti-UnitResidentialBuildingCharacteristicsintheCityofToronto,”EnergyandBuildings66(2013)pp.648-656.
Edwards,C.(1999).ModellingofVentilationandInfiltrationEnergyImpactsinMidandHigh-RiseApartmentBuildings.
A-RockyMountainInstitute,SuperefficientAffordableHousing:SolutionstoHurdles,2013
http://www.rmi.org/retrofit_depot_the_blueprint_enacting_a_deep_energy_retrofit