Buildingsuseabout40%ofthetotalU.S.energydemand.Waterheatersprovidehotwaterforavarietyofbuildingusesincludingsinks,showers,dishwashers,washingmachines,andspaceheaAng.Waterheatersarethesecondmostenergyintensiveappliancesinacommonhousehold.Typicallyahomewaterheater’senergysourceisnaturalgas.ThereareothertypesoftankwaterheatersincludeultralowNOx,andelectricresistance.Figure1displaysthedifferencesinwaterheatertypes.Electricresistancewaterheatersuseelectricalgridpower.BuildingownersburdenthecostofwaterheaAngthroughtheiniAalwaterheatercost,energybills,andthecommunalairpolluAontheybreathe.BurningandextracAngnon-renewablefuelsincludingnaturalgasleadstoclimatechange.WaterheatersnoAceablyaLributeairpolluAontowinterinversionshaveadverseaffectsonhumanhealth.CombustedairpollutantsincludeCarbonDioxide(CO2),Nitrogenoxides(N0x),andSulfuroxides(SOx).PushingtowardsthefutureSaltLakeCityhassetagoaltoreduce80%ofgreenhousegasesemissionsbytheyear2040seUngademandforwaterheateremissionsreducAon.
ImprovingWaterHeatersforSustainabilityNicholasMalinowskiUniversityofUtahDr.AmandaD.SmithUniversityofUtah
ThisresearchaimstoquanAfyenergyandemissionseffectsforvariouswaterheaters.EnergyPlusabuildingmodelingso[wareuAlizesacomprehensivebuildinginformaAonfileandlocaAonspecificweatherfiletoperformanannualenergydemandsimulaAonforabuildingshotwaterusagedeliveredbyawaterheaAngsystem.Modelkitso[warewasusedtoperformmulApleEnergyPluscalculaAonsatoncewithmodifiedvariablesforwaterheaterfuelsourcetype,andthermalefficiency.Matlabcodingso[wareinputsthewaterheaterenergydemanddatatonumericallyandgraphicallyanalyzeenergyusage,andemissionsonvariousAmescales.
Theresultsinfigure2and3showannualwaterheaterenergyconsumpAonandsavingsperweekforwaterheaterswithefficienciesrangingfrom90to95%.Alltrendsdisplaythematchingwaterheaterefficiencydeliveringthesameamountofenergytothewater.Week6duringwinteristhehighestdemandforwaterheaAngduringtheyearandweek34inthesummeristhelowestdemandforwaterheaAng.Figure4and5displayannualwaterheateremissionsandsavingsperweekforwaterheaterswithefficienciesrangingfrom90to95%.TheCO2emissionsarethedominaAngtrendsforbothwaterheatertypes.TheelectricwaterheatersgeneratemoreCO2withthecurrentSaltLakeCityelectricitygrid.EmissionsforNOx,andSOxappearinsmallamountsattheboLomofthegraphs.
Acase-by-casebasisisthebestwaytocorrectlysizetherightequipmentforabuildingshotwaterdemand.Thegraphsdemonstrateforbothwaterheaterfuelsourcestypesanincreaseofthermalefficiency,decreasestheenergyconsumpAon,decreasestheemissions,andincreasestheenergyandemissionsavings.ThewaterheatersCO2emissionsarerelaAvelyhighcomparedtoNOx,andSOxemissions.ElectricresistancewaterheatersproducemoreCO2withthecurrentelectricitygrid.IncreasingtheefficiencyofanelectricresistancewaterheaterhasalargereffectofreducingCO2emissionscomparedtoanaturalgas.ElectricwaterheatersgivetheopAonforbuildingelectrificaAon.
Acknowledgements/References:ThisworkwassupportedbytheUniversityofUtahOfficeofUndergraduateResearch.UseofdatawassupportedbytheU.S.DepartmentofEnergyforbuildingfilesandEnergyPlusforweatherfiles.TheModelkitprogram
usedwasdevelopedbyBigLadderSo[ware.Thewaterheaterdiagramwaslocatedfromwww.agendadepaznarino.com
Figure1–ElectricResistanceandNaturalGasWaterHeaters
Table1–WaterHeaterValues
NicholasMalinowskiUniversityofUtah
I. IntroducAon
II.Methods III.Results
IV.ConclusionsFigure2&3–AnnualWaterHeaterEnergyConsumpAonandSavingsPerWeek
Figure4&5–AnnualWaterHeaterEmissionsGeneratedandSavedPerWeek
ModelhybridtankwaterheaterequipmentwithEnergyPlus.UAlizerealbuildingwaterheaterenergyusagetoperformcalculaAonsforesAmateimplicaAonsofwaterheaterchoices.
V.FutureWork
