人体舒适度的温湿度指标

ütistr.50,CH-8712StäfaZH,Switzerland,Tel:[phone],Fax:[phone]SHTxxHumidity&TemperatureSensmitterApplicationNoteConditionsofThermalComfort1IntroductionThermalcomfortisdefinedasthatconditionofmindwhichexpressessatisfactionwiththethermalenvironment.Alotofempiricaldatahasbeencollectedonhowtheseconditionsaredefined.Thisapplicationnotegivesashortintroductiononthermalcomfortespeciallyinrespectofhumidityandtemperature.Thefactorsthathaverelevantinfluenceonthethermalcomfortofoccupant’sspacescanbegroupedinenvironmentalandpersonalfactors.Environmentalfactors:-temperature,thermalradiation,humidity,airspeedAirvelocityisnotinthescopeofthisdocument.Generally,itcanbesaid,thatairdraughtshouldbeavoidedaltogetherforsedentarypersons,sinceitisanunwantedlocalcoolingofthebodycausingdiscomfort.Personalfactors:-activity,clothingAcceptanceofthethermalenvironmentandtheperceptionofcomfortandtemperaturearerelatedtometabolicheatproduction,itstransfertotheenvironment,andtheresultingphysiologicaladjustmentsandbodytemperatures.Activityismeasuredastherateofenergyproductionofthebody.Metabolism,whichvarieswithactivity,isusuallyexpressedinmetunits.Onemetisdefinedas58.2W/m2,whichisequaltotheenergyproducedperunitsurfaceareaofaseatedpersonatrest.Thesurfaceareaofapersonisabout1.8m2.Conditionsforcomfortgiveninthisdocumentrefertoapersonwhoisdoinglightsedentaryactivity(≤1.2met).Clothing,throughitsinsulativeproperties,isanimportantmodifierofbodyheatlossandcomfort.Clothingischangingtoagreatextentbytheseasonandoutdoorweatherconditions.Duringthesummermonths,typicalclothingincommercialestablishmentsconsistsoflight-weightdresses,lightweighttrousers,short-orlong-sleevedshirtsandblouses,andoccasionallyasuitjacketorsweater.Duringwinterseason,peopleweargarmentsconstructedofthicker,heavier(warmer)fabricsandoftenaddmoregarmentlayerstoanensemble.Conditionsforcomfortgiveninthisdocumentrefertopersonsinsuchtypicalsummerandwinterclothings.Becauseofindividualdifferences,itisimpossibletospecifyathermalenvironmentthatwillsatisfyeveryone.Conditionsstatedinthisdocumentwillensurethat80%ormoreoftheoccupantswillfindtheenvironmentthermallyacceptable.TheconditionsofcomfortwerefoundbystudiesofNorthAmericanandEuropeansubjects.RecentstudieswithJapanesesubjectsledbasicallytothesameresults.Therefore,itcanbeassumedthattheseconditionsofcomfortcanappliedwithgoodapproximationinmostpartsoftheworld.SHTxxApplicationNoteStatusRegister:energycanbesavedwhenindoorspacesaremonitoredforbothhumidityandtemperature,becausee.g.whenhumidityislow,ahighertemperatureisacceptableandcoolingisnotnecessary.Incomparisonasystem,whichisonlycontrolledtoreachacertainsetpointfortemperature,willdounnecessaryheatingorcoolingforRH/Tcombinations,whichalreadylayinthecomfortzone.Theboundariesofthediagramsaredefinedthrough:Winter:temperaturet=19.5°Cto23.5°C(67.1°Fto74.3°F)at18°C(64°F)wetbulbtemperatureandt=20.5°Cto24.5°C(69°Cto76°C)at2°C(36°F)dewpoint.Theslantingsideboundariesofthewinterzonecorrespondto20°Cand23.5°C(68°Fand74.3°F)effectivetemperature,meaningiftheparametersmovealongthisline,comfortorthermalsensationsstayconstant.Summer:temperaturet=22.5°Cto26°C(73°Fto79°F)at20°C(68°F)wetbulbtemperatureandt=23.5°Cto27°C(74°Fto81°F)at2°C(36°F)dewpoint.Theslantingsideboundariesofthesummerzonecorrespondto23°Cand26°(73°Fto79°F)effectivetemperature.1Americansocietyofheating,refrigeratingandair-conditioningengineers,IncSHTxxApplicationNoteStatusRegister“summer”and“winter”comfortzones,atranslationcanbemadeintoanRH/Tdiagram,usinganapproximationbyjustcalculatingRHvaluesforthecornerpointsofthequadranglesgivenabove:TRH58.3%29.3%0%23.5°C74°F86.5%20.5°C69°F24.5°C76°F23.5°C74.3°F23%19.5°C67.1°F100%57.3%24.4%79.5%19.8%WinterSummer26°C79°F27°C81°F22.5°C73°FFigure2RH/TdiagrambasedoncomfortzoneaccordingtoASHRAE55-19923ComfortzoneaccordingtoISO7730AnotherapproachfordefiningthecomfortzoneistakenbythestandardISO7730.Itneglectsthefact,thathighertemperaturescanbebornebetterifhumidityislower.Thereforeitsupperandlowertemperaturelimitsarevertical.Thisapproachcanbeusedinlessdemandingapplicationsforsimplerimplementationofair-conditioningalgorithms.3.1TemperatureThetemperatureintheoccupant’sspaceshouldbe:Season°C°FWinter20-2468-75.2Summer23-2673.4–78.83.2HumidityTherelativehumidityshallbebetween30%and70%inwinteraswellassummertime.Thelimitsaresettodecreasetheriskofunpleasantlywetordryskin,eyeirritation,staticelectricity,microbialgrowthandrespiratorydiseases.SHTxxApplicationNoteStatusRegister°C/78.8°F24°C/75.2°F23°C/73.4°F20°C/68°FSummerWinter100%TFigure3RH/Tdiagrams