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PAGE 1 Florida Energy Extension Service TheInstituteofFoodandAgriculturalSciencesisanEqualOpportunity/AffirmativeActionEmployerauthorizedtoprovideresearch,educational informationandotherservicesonlytoindividualsandinstitutionsthatfunctionwithoutregardtorace,color,sex,ornationalorigin. FloridaCooperativeExtensionService/InstituteofFoodandAgriculturalSciences/UniversityofFlorida/JohnT.Woeste,DeanSelectingaCeilingFan1RonaldJarnagin2Analternativetoconsiderwhenattemptingto reduceair-conditioningcostsisaceilingfan.Ceiling fansareavailableinvarioustypes,sizes,andstylesto suityourneeds.Theuseofaceilingfanwillallow youtooperateyourairconditioneratahigher thermostatsettingthanusual,sincetheairmovement createdbyafanproducesacoolingeffectonthe body.COMFORTTherehavebeenmanyattemptstodeterminethe conditionsthatmakeapersonfeelcomfortable.The factorsthatinfluencehumancomfortareasvaried andcomplexastheindividualsthemselves.However, themajorfactorsthataffectpersonalcomfortinthe homeareairtemperature,relativehumidity,andair movement. Aceilingfanhasnoeffectonthefirsttwofactors. Onlythehomeairconditionercanaffectboththe temperatureandthehumidityinthehouse.The ceilingfan,ontheotherhand,canincreaseair movementinaroom,thuscreatingacoolingbreeze thatwillhelptoincreaseyourlevelofcomfort. Airmovementhelpstokeepyoucoolprimarilyby increasingtherateofevaporationofmoisturefrom yourskin.Increasingtheamountofairmovement willallowyoutofeelcomfortableathigherthan normaltemperatures.However,higherhumidity levelswillmakeitmoredifficultforthefantohave abeneficialeffect. 1.ThisdocumentwaspublishedasFactSheetEES-31,FloridaEnergyExtensionService.Formoreinformation,contactyourcountyCooperative ExtensionServiceoffice.2.MechanicalEngineeringSpecialistforFloridaEnergyExtensionService,InstituteofFoodandAgriculturalSciences,UniversityofFlorida, Gainesville. TheFloridaEnergyExtensionServicereceivesfundingfromtheGovernor'sEnergyOffice.Theinformationcontainedhereinistheproductof theFloridaEnergyExtensionServiceanddoesnotnecessarilyreflecttheviewsoftheGovernor'sEnergyOffice. PAGE 2 SelectingaCeilingFan Page2 Mostpeopleareawareofairvelocitiesofaround 200feetperminute,whichcorrespondstoabreezeof 2-1/2mph.Ceilingfansarecapableofproducingair velocitiesintherangeof200to700feetperminute, dependingonthespeedsetting.Ofcoursethe comfortyoureceivefromairmotionoverthebodyis strictlyanindividualmatter.CEILINGFANEFFICIENCYTheefficiencyofafanmaybedeterminedifthe powerconsumptioninwattsandtheairflowratingin cubicfeetperminute(cfm)areknown.This informationisusuallycontainedinthemanufacturer's literaturethataccompaniesthefan.Forfansthat havevariablespeeds,youmayfinddifferent efficienciesdependinguponthespeedsetting(fan efficiency=airflow(cfm))powerrequiredwatts.Be surewhencomparingtwofanstousetheefficiency calculatedatthesamefanspeed(usuallythehighest speed). Tocalculatetheefficiencysimplydividethe airflowratingincfmbythepowerconsumptionin watts.Thehigherthecfmperwatt,thehigherthe efficiencyofthefan.Higherefficienciesrelate directlytoloweroperatingcosts.Typicalfiguresfor fanefficiencyshouldrangefrom150to200cfmper watt,whencalculatedatthehighestfanspeed.In general,alargerdiameterfanwillbemoreefficient thanasmallerdiameterfan.FANSIZINGCeilingfansizesaredeterminedbythediameter ofthefanblades.Youcanfindfansrangingin diameterfrom24inchesupto60inches,withseveral sizesinbetween.Themostcommonandreadily availablefansizesare36inchesand52inches.A largerfanwillbeabletomovemoreairthana smallerfanandthuswouldbesuitableforlarger rooms. Choosingthepropersizeceilingfanforyour homerequiresalittlethoughtaboutyourparticular application.Doyouwantacentrallylocatedfanto helpkeepyoucoolinalargefamilyorlivingroom? Ifso,thenthe52inchfanshouldbeyourchoice.If youonlywishtoprovidebreezesforasmall10by10 footbedroom,thenthe36inchfanshoulddojust fine.Rememberthatthelargerfanwillmovemore airthanthesmallerone,sowhenindoubtchoosethe 52inchfan. A36inchfanoperatingathighspeedmovesthe sameamountofairasa52inchfanoperatingata lowerspeed.Operatingatalowerspeedreduces boththeoperatingcostandthenoiselevel.Itisno wonderthatthe52inchfanismostoftenchosenfor economicalwhisper-quietoperation.OPERATINGCOSTSCeilingfansrequireverylittleenergytooperate. Forexample,atypicalceilingfanusesonlyaboutas muchenergyasanincandescentlightbulb.Ifyou weretooperateyourceilingfanfor10hoursdaily,it wouldonlycostyouabout6to8centsperday.For comparisonpurposes,atypical3tonairconditioning unitoperatedfor10hoursdailycouldcostyouabout $3.00to$5.00perday. Thepreviousexampleisnotmeanttoimplythat aceilingfancanreplaceanairconditioningunit.In timesofmoderatetemperatureandhumidity,the ceilingfanmayprovideallthecoolingthatisneeded. Thisisespeciallytrueinthefallandspringseasons. However,mostofthetimetheceilingfanwillbeused inconjunctionwiththeairconditioningsystemto providecomfort. Inordertoachieveasavingsthroughuseofthe fan,youmustraisetheairconditioningthermostat settingwhileusingthefan.Raisingthethermostat PAGE 3 SelectingaCeilingFan Page3 settingwillcausetheairconditionertooperateless, thussavingyoumoney.Theceilingfanwillprovide thegentlebreezestokeepyoucoolsothatyoudo notrequireasmuchairconditioning.INSTALLATIONHINTSCeilingfaninstallationkitsgenerallycomeintwo types.Thefirsttypeofinstallationkitisonethat mountsthefantoanelectricaloutletboxoverhead. Thesetypesofmountingsfrequentlytaketheplaceof anexistinglightfixture.Oneadvantageofthistype ofinstallationisthatitcanreducewiringcosts. However,becarefulwhenusingelectricalboxessince theyarenotusuallyadequatelybracedtoholdthe weightofaceilingfan.Iftheelectricalboxhasbeen wellsecuredwithadditionalbracing,thisisan excellentmethodofmounting.Rememberthatyou mayhavetoaddalightkittothefaninorderto replaceanylightfixturesthatwereremoved. Asecondmethodofmountingaceilingfanis withalargewoodscrewthathasahookontheend. Thesescrewsarespeciallydesignedtoholdtheweight ofthefan.Thescrewislongenoughsothatitcan passthroughtheceilingpanelsandbesecuredinthe woodenstudsthatformtheceilingjoists.Sincethese screwsserveaspecialfunction,youshouldnever substituteahardwarestorereplacement.Useofthis typeofmountingrequiresthatastudbelocated whereyouwishtohangthefan.Fansarefrequently hunginthismannerinapartmentsandotherhousing wherethereisnoaccesstotheattic.Electricalwiring isusuallyprovidedthroughtheuseofaswagkit. Fansshouldbemountedatleast7feetabovethe floorinordertominimizethehazardtoindividuals fromcomingcontactwiththemovingblades.In placeswherethisisnotpractical,youmightwantto considerarrangingfurnituresothatsomeonecannot standdirectlyunderthefan.Placingafanoverthe bed,diningroomtable,orlargecoffeetablecan frequentlysolvefanheightproblems.The"ceiling hugger"fansthatattempttosolvethisproblemby eliminatingthedownrodarenotasefficientas conventionallyhungfans.AVAILABLEFEATURESWhenselectingyourceilingfanyouwillfindthat therearemanyavailablefeaturesfromwhichto choose.Someofthesefeaturesarefunctionaland somearedecorative.Manyfeaturesmaybeavailable onlyatextracost.Youshoulddeterminewhich featuresarethemostimportanttoyousothatyou canmakeintelligentcomparisonswhenshopping. MotorSpeed .Youwillneeddifferentspeedsin ordertoobtainacomfortablesettingundervarying conditions.Atleastthreespeedsaredesirable. Continuouslyvariablespeedsofferthemaximum control. MotorType.Themotorshouldbeoftheballbearingtypeandmaybepermanentlylubricatedor requireperiodiclubrication. Blades.Mostresidentialfanshavefourbladesof eitherplastic,metal,orwoodconstruction.Metal bladesmayhavesharperedgesandcansometimesbe noisyinoperation.Ifusednearsaltwater,metal PAGE 4 SelectingaCeilingFan Page4 bladescancorrode.Woodbladesmustbetreatedto resistabsorbingmoistureandwarping. ReverseAirFlow .Thisfeatureallowsthedirection ofairflowtobereversed.Suchafeaturemaybe desirablewhenfansarelocatedoverbedsordining tables,sincetheseareareasinwhichyoumaynot wanttohaveairblowingdirectlyonyou.The frequentlyquotedwinterbenefitsofreverseairflow areprobablynotsignificantinsouthernclimates. Warranty.Awarrantymaycoveraperiodfrom oneyearuptothelifetimeofthefan.Youshould investigatethetermsofthewarrantytofindout exactlywhatiscoveredandwherethewarrantyclaims willbeserviced.Somefansmustbereturnedtothe manufacturerratherthanthedealerforservice. |