Lesson1GlobalWarming公開課比賽一等獎(jiǎng)

DESIGNINGANDBUILDINGANEWHOUSE

Didyouknowthatanenergy-efficienthousecoulduse90percentlessenergythanonedesignedconventionally?

Beingenergy-efficientispartofabiggerpicture,thatis,‘ecologicallysustainabledevelopment’.Thismeanstakingcareofourplanet:conservingscarceandvaluableresources,ensuringthehealthofalllivingcreaturesandvaluingandcaringforournaturalenvironments.Whenwetalkabout‘ecologicallysustainabledevelopment’wemeanusingresources,buildingcitiesandfactories,producinggoodsandchangingenvironmentsinwaysthatarenotthreateningtooursurvivalandourplanet.

ThemajorityofhomesinurbanareasofAustraliauseenergyfromoneortwosources:electricityandgas.Energyisusedinthreemainways:tolightourhouses,torunappliancesandtoheatorcoollivingareasorwater.Theseenergysourcesarefairlyinexpensiveineconomicterms,thatis,indollarsspentbytheconsumer,andincoststothecommunitytoestablishpowerstations.Bothofthesesourceshavenegativeimpactsontheenvironment.Thenegativeimpactsoccuratthesiteswheretheyareextractedfromtheearth,andatthepowerstationswheretheyareburnedtoproduceelectricity.

InAustraliaweusesomewherebetween10and15percentofthetotalenergyweproduceinourhomessoitisveryimportantwedoallwecantobemoreenergy-efficient.Ifwecanmakeourhousesmoreenergy-efficient,itmeansthatwewilluselessnon-renewableenergy.Burninglesscoalandgaswillreducethegreenhousegasesreleasedintotheenvironment.Wehavegreatopportunitiestobemoreenergy-efficientwhenwedesignandbuildnewhomes.Howcannewhousesbedesignedtobemoreenergy-efficient?

What’simportantinhousedesign?

Housescanbedesignedsothattheycanbeheatedandcoolednaturally.Itcanbeassimpleastrappingthesun’sheatinwintertowarmthehouse.Ahousecanalsobedesignedtokeepthesummerheatoutandtousenaturalbreezestokeepthehousecool.Therearetwoimportantthingsaboutthesuntorememberwhendesigningahouse:

Asitrisesandsetseachday,thesunmovesacrossanorthernpathinthesky;

Thepositionofthesunintheskyinsummerishigherthaninwinter.

Tokeepyourhomewarminwinteryoucanuseallthesedesignfeatures:

Planasmanywindowsaspossibleonthenorthernwallstotrapthesun’sheat

Arrangethelivingareasonthenorthernsideofthehouse

Buildtheinternalwallsofbrickorconcretetoabsorbtheheatduringthedayandwarmthehouseduringthenight

Hangthickcurtainstopreventheatbeinglostthroughwindowsatnight

Installinsulationinthewallsandceilingstohelpstopheatlosstotheoutside

InsomepartsofQueensland,suchasthetropics,winterheatingisrarelyneeded.

Whatarethefinancialandecologicalfactors–costsandbenefits–ofthesefeatures?

Tokeepyourhomecoolinsummeryoucanuseallthesedesignfeatures:

Shadethenorthernwindowsofthehousewitheaves,awnings,orapergola

Plantdeciduoustreesonthenorthernsideofthehouse–whentheylosetheirleavesinwinterthesunshinewillenterthehouseandinsummertheleaveswillshadethehousefromtheheat.Consultyourlocalcouncilandnurseriesforsuitabletrees.

Shadewindowsontheeasternandwesternsidesofthehouse

Insulatethewallsandceilingtocutdownonheatenteringthehouse.

Whatarethefinancialandecologicalfactors–costsandbenefits–ofthesefactors?

Howimportantisinsulationinahouse?Veryimportant.Lookatthesefigures.Thissketchshowsyoutheapproximateheatgainsinsummerandheatlossesinwinterintheaverageuninsulatedhome.Thesefiguresvaryaccordingtotheseasonoftheyear,theconstructionmaterialsusedandthedesignofthehouse.

Whendesigningnewhousesgreaterenergyefficiencycanbeobtainedifthedesignincludes:

Apassivesolardesign;and

Anactivesolardesign.

Apassivesolardesignuseswindowsize,locationandshading,alongwiththegeneralorientationordirectionofthehouse.

Anactivesolardesigninvolvesheatingandcoolingappliancesthatusethesun’senergy.

Solarenergymakessenseinnewhousedesignsandforexistinghouses.

Itispossibletoprovideelectricityforawholehousefromphotovoltaicsolarcells–youcouldevenpoweryourtelevisionsetwithsolarelectricity.‘Photo’meanslightand‘voltaic’meanselectricity.Atpresentitismoreexpensiveineconomic,ordollar,termstoinstallsolarcellsforelectricity,butrunningcostsarerelativelylowcomparedtopurchasingcoal-orgas-firedelectricity.Thecostofproducingsolarcellsisgettingcheaper.

Solarcellscancauseenvironmentaldamagewhentheyarebeingmade.Siliconisfoundinthesandandminingsuchsandcandamagelocalhabitats.Also,energyisneededtomakethemetal,glassandplasticpartsofthesolarcells.

Apartfromsomenegativeimpactsoftheproductionofsolarcellsontheenvironment,solarenergydoesmakegoodsenseecologically.Whydoesn’teveryoneinstallone?Whatotherfactorsmustpeopletakeintoaccount?

Someconsumersinneworexistinghomesareinstallingsolarhotwatersystems.Thesearedifferentfromsolarcells.Theydonotproduceelectricitybutheatthewaterusingsolarenergy.Again,thesesolarpanelsareinitiallyexpensiveto