Whole House Fans: Installation

http://edis.ifas.ufl.edu/ ( Publisher's URL )
MISSING IMAGE

Material Information

Title:
Whole House Fans: Installation
Physical Description:
Fact sheet
Creator:
Cook, Gary D.
Publisher:
University of Florida Cooperative Extension Service, Institute of Food and Agriculture Sciences, EDIS
Place of Publication:
Gainesville, Fla.
Publication Date:

Notes

Acquisition:
Collected for University of Florida's Institutional Repository by the UFIR Self-Submittal tool. Submitted by Melanie Mercer.
Publication Status:
Published
General Note:
"Publication date: November 1992"
General Note:
"EES-33"

Record Information

Source Institution:
University of Florida Institutional Repository
Holding Location:
University of Florida
Rights Management:
All rights reserved by the submitter.
System ID:
IR00004845:00001


This item is only available as the following downloads:


Full Text

PAGE 1

FactSheetEES-33 November1992 WholeHouseFans:Installation1 GaryD.Cook2Aproperlysizedwholehousefanisdesignedto pulllargequantitiesofoutsideairthroughscreened windowsanddoorsandpushitthroughtheattic. Whenthereisinsufficientclearanceinatticexhaust areas,thewholehousefancanbeinstalledtoexhaust directlyoutsidethroughthewall.Maximumbenefitis obtainedwhenthefanexhauststhroughtheattic becauseitcoolsboththeatticandtheoccupants. Thisdiffersfromatticfanswhicharedesignedtocool theatticonlyandarenotcosteffectiveiftheatticis wellinsulated.(SeeFigure1).SIZINGAwholehousefanshouldbesizedtoprovidean airflowratebetween1.5and4cubicfeetperminute (CFM)persquarefoot(SF)offloorareaoftheresidence.A2000SFhomeshouldhaveafancapableof deliveringbetween3000and8000CFM.Twosmaller fansofthesamesizeproperlylocatedandinstalled maybeused,butcaremustbetakentooperatethem atthesametimetoavoidreverseflow.Thehighend ofthescalewillprovidethebestreturninsavings. (RefertoTable1.) Fanscaneitherbedirectorbeltdrive.Belt drivenfansareusuallyoflargersizeswithgreater capacities,andtheymayrequiremoremaintenance. Afeatureyoushouldinsistonineithercaseisahigh temperatureswitchwhichautomaticallyshutsthefan Figure1.ExhaustFansvs.AtticFans offincaseoffire. TheFloridaModelEnergyEfficiencyCodeallows 5creditpointsforawholehousefanprovidingat least1.5CFM/SF.Thisisasignificantbonusfor residentialbuilderslookingforwaystoreducetheir EnergyPerformanceIndex(EPI).ThelowertheEPI thebettertheenergyperformanceofaresidence. BonuspointsaresubtractedfromthegrossEPI points. 1.ThisdocumentisFactSheetEES-33,aseriesoftheFloridaEnergyExtensionService,FloridaCooperativeExtensionService,InstituteofFood andAgriculturalSciences,UniversityofFlorida.Publicationdate:November1992. 2.GaryD.Cook,EnergyExtensionSpecialist,SchoolofBuildingConstruction,CooperativeExtensionService,InstituteofFoodandAgricultural Sciences,UniversityofFlorida,GainesvilleFL32611. TheFloridaEnergyExtensionServicereceivesfundingfromtheFloridaEnergyOffice,DepartmentofCommunityAffairsandisoperated bytheUniversityofFlorida'sInstituteofFoodandAgriculturalSciencesthroughtheCooperativeExtensionService.Theinformation containedhereinistheproductoftheFloridaEnergyExtensionServiceanddoesnotnecessarilyreflecttheviewsoftheFloridaEnergyOffice. TheInstituteofFoodandAgriculturalSciencesisanequalopportunity/affirmativeactionemployerauthorizedtoprovideresearch,educational informationandotherservicesonlytoindividualsandinstitutionsthatfunctionwithoutregardtorace,color,sex,age,handicap,ornational origin.Forinformationonobtainingotherextensionpublications,contactyourcountyCooperativeExtensionServiceoffice. FloridaCooperativeExtensionService/InstituteofFoodandAgriculturalSciences/UniversityofFlorida/ChristineTaylorStephens,Dean

PAGE 2

WholeHouseFans:Installation Page2 Figure2.RequiredClearencesINSTALLATIONGUIDELINESThesearegeneralguidelinesforlocationand placementofawholehousefan.Ifthesegeneral guidelinescanbemet,thefanmaybepurchased,and thespecificinstallationinstructionsofthe manufacturershouldthenbefollowed. Thewholehousefanshouldbelocatedproperly withinthehouseandhaveenoughclearancebehind thebladestoreducebackpressure.Thereshouldbe ampleexhaustopeningsintheattictominimizeback pressure. Tobemosteffective,thefanshouldbeplaced horizontallyintheceiling,providedthereisavertical spaceofatleast20inchesabovetheblades(Figure 2).Obstructionssuchastherooforachimneycreate abackpressure.Thiswillreducethefanefficiency andincreasethenoise.Thefanshouldbelocatedin ornearacentralhallway(Figure3)orcentralportion ofthehousesothatitcanventilatetheentirehouse. Generally,the24"fanswillfitbetweenceiling joists.Thelargerfans(30"-42")muststraddlethe joistsinthemannershowninFigure4. CAUTION:Itisveryimportantthatstructural members(ceilingjoistsortrusses)notbecuttothe pointtheyareweakened. Ifceilinginstallationisfoundtobeunsuitable, youmayconsiderinstallationthroughanoutsidewall. Beforeattemptingthisalternative,consulta knowledgeablefansupplierorbuilder. Figure3.FanLocation. Shuttersthatopenautomaticallywhenthefanis Figure4.CeilingFansandJoists. turnedonshouldbeinstalledtoreduceinfiltration andheatexchangetoandfromtheatticwhenthefan isnotinoperation.Somebuilderswillinstall prefinishedsheetsoffoaminsulationthatwillslideon atrack.Thissheetfitsinfrontoftheshuttersand mustbeslidoutofthewaybeforethefanisturned on.Thisismoreeffectiveatreducingheattransfer thantheshuttersaloneanditcanbemadetolook moreattractive.

PAGE 3

WholeHouseFans:Installation Page3 HouseSize(SF) WholeHouseFan Capacity1.5CFM/SF Range4CFM/SF FanSizeDia.HP 1000 1500 4000 24"(1/4HP) 1200 1800 4800 24"-30"(1/4-1/3HP) 1400 2100 5600 24"-30"(1/4-1/2HP) 1600 2400 6400 24"-36"(1/4-1/2HP) 1800 2700 7200 24"-36"(1/4-1/2HP) 2200 3300 8800 30"-36"(1/2-1/2HP) 2600 3900 10,400 30"-42"(1/2-3/4HP) Atticexhaustopeningsmusthaveenoughopen Figure5.AtticExhaustOpenings. areatoallowtheairtogetoutoftheattic.Openings maybeacombinationofseveraltypes:louvered shutteredopeningsatgableendsordormersand soffitoreavevents.Metallouversgivelessresistance toairflowthanwoodslotsorlouvers. Wholehousefanmanufacturersrequireacertain amountoffreeorunobstructedexhaustareato minimizebackpressureandfanoverload.Sincemost atticopeningsareobstructedwithscreenandlouvers, extragrossareamustbeprovided.Table2isa generalguidelinefordeterminingthenetscreened Table2..Netscreenopeningrequirements. FanDiameter MinimumScreened Area(SF) 24" 5.8 30" 8.2 36" 11.5 42" 16.2 Note:Only 50% ofthegrossareaofwoodlouvers isconsideredfreearea.Only64%ofthegross areaofmetallouversisconsideredfreearea. Remember,thesearegeneralguidelinestodetermineifyourresidencewillsuitablyaccommodatea wholehousefan.Themanufacturer'sspecificinstallationinstructionstakeprecedenceoverthese guidelinesandshouldbefollowed.openingrequired.BIBLIOGRAPHYCook,GaryD.,"AGuideToResidentialEnergy EfficiencyinFlorida,"EES7,EnergyExtension Service,InstituteofFoodandAgricultural Sciences,UniversityofFloridaincooperation withtheGovernor'sEnergyOffice,1981. Cook,GaryD.,"Design,MarketingandOperationof EnergyEfficientBuildings,"EnergyExtension Service,InstituteofFoodandAgricultural Sciences,UniversityofFloridaincooperation withtheGovernor'sEnergyOffice,1982(limited edition). Emerson,R.,"OwnersManual:VariableSpeed WholeHouseFan,"EmersonEnvironmental

PAGE 4

WholeHouseFans:Installation Page4Products,Bennettsville,SouthCarolina, December1980. Farber,E.A.,Wiggins,D.B.,Podris,F.I.,Murdoch, J.A.,"AtticVentilation,"TechnicalReport, FloridaGovernor'sEnergyOfficeincooperation withSolarEnergyandEnergyConversion Laboratory,UniversityofFlorida.