资源描述：
《how air conditioning works外语英文电子书》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。
1、1HowairconditioningworksTheessentialingredientsinanairconditioningsystemareafantoblowairaround,acoldsurfacetocoolanddehumidifytheair,awarmsurfaceandasourceofwatervapour.Inalargesystemtherewillalsobeatangleoftubestodistributetheairandcollectitagain.Noticethatthecoldsurfacehastwoind
2、ependentjobstodo:itisusedtocooltheairanditisalsousedtodehumidify,bycondensingwaterfromtheair.Thismeansthattheairiscooledmorethanisnecessaryfortemperaturecontrol,sothatitmustbeheatedagainafterwards.Airconditioningwastesenergy.Italsowastesspace,becauseairhastobepumpedaroundinquitela
3、rgetubes,sothatitdoesn'tmakearushingnoise.Itdoes,nevertheless,generateadisturbingbackgroundnoiseiftheroomisotherwisequiet.Thereisworsenewstocome:airconditioningisspreadingtomoreandmorebuildingsinclimatesthatweoncethoughtweresomildthattheywouldbeimmune.Theoriginofthistechnologicale
4、pidemicisnotthesubjectofthisarticle.Iwillhowevermentionsomereasonswhicharerelevanttomuseumconservators.Modernmuseums,andoldonesaswell,areshowpiecesdesignedtobeadmiredforboldandoriginalarchitecture.Theytendtobemassive,andthoseoldmuseumswhichoriginallyhadcourtyardstogivelightandaira
5、renowglassedoverwithdomesandatria.Theheatandmoisturecannoteasilyescapetotheoutside:theyhavenowtobepumpedout.Thesubtleeleganceofbuildingsdesignedfortheirpurposecountsforlittlenowadays.GrandGesturesarefashionable,andairconditioninghidesthearchitects'andengineers'lackofunderstandingo
6、rrespectfornaturalventilation.Onemustsaythatconservatorshavereinforcedthistrend,becausetheyhavesetspecificationsforallowablevariationoftemperatureandrelativehumiditythatcanonlybeachievedbymechanicalairconditioning.2Thepurposeofthisarticleistoexplainhowairconditioningworks,inordert
7、oshowwhyonecannotjustpluckvaluesfromsomestandardorrecommendationwithoutriskingunexpectedpenaltiesinenergyuse,maintenancecostandnoise.Furthermore,oncethemessofsteelboxesandductsisinstalled,youcannotdialthetemperatureandhumidityexactlyasyouwantthemwithoutriskingsurprisinglyexpensive
8、sideeffectsofenergyconsumption,cl
