LABVENTILATIONDESIGNBy:JohnC.Palasz,PE,HFDPPrimeraLabVentilationSystems1TableofContentsSECTIONIINTRODUCTION............................................................................................2SECTIONIIPROTECTINGPEOPLE(ANDEXPERIMENTS)..............................................3SECTIONIIIUNDERPRESSURE......................................................................................4SECTIONIVROOMCONSTRUCTION/ROOMLAYOUT....................................................5SECTIONVVERIFYINGSYSTEMOPERATION.................................................................6SECTIONVILABVENTILATIONSYSTEMOPTIONS.........................................................6SECTIONVIILABSPACEORCLASSROOMSPACE?.........................................................9SECTIONVIIICONCLUSION.............................................................................................11PrimeraLabVentilationSystems2I.IntroductionIfyouareaFacilitiesDirectoratanelementaryschool,highschool,oruniversityandhavebeentaskedwithconvertingastandardclassroomtoachemistrylabspace,howdoyoudecidewhattypeofventilationsystemtouse?Youmayknowyouwillneedlabhoodswithexhaustfansconnectedtothem,butwhereshouldthemakeupaircomefrom?Youknowthatprotectingusersfrompotentiallytoxicfumesisyourtoppriority,butdoyoualsoneedtoprotecttheexperimentsfromcontamination?Isa“cleanroom”environmentrequired?Youknowlaboratoryventilationsystemscanuselotsoffreshairandbeexpensivetooperate,butyoualsowanttousethespaceasaclassroom–canasystembedesignedtosatisfybothrequirements?Asyoumayhavealreadynoticedtherecanbealotofquestionsthatneedanswersanddecisionsthatneedtobemadewhenworkingwithlaboratoryventilationsystems.Inthefollowingpages,we’lltakeanin-depthlookatsomeoftheconsiderationstothinkaboutinplanningyournextlaboratorydesignproject.PrimeraLabVentilationSystems3II.ProtectingPeopleandExperimentsLaboratoryventilationisdifferentthanmostotherbuildingtypes.Forrenovationprojects,whereanoffice,classroom,orotherspaceisbeingtransformedintoalabspace,designofteninvolvesasignificantchangetotheventilationsystem.Whilealllabventilationsystemsaredesignedtoprotectpeople,therearealsootherendgoalsinmind,suchastheneedtoseparatecontaminantsandpreventexperimentsfrombeingcompromised.Inthisrespecttheventilationsystemisintendedtomaintaincleanareasaspositivepressurezonesandpotentiallytoxicareasasnegativepressurezones.Whendangerouschemicalsareused,thelabventilationsystemisessentialinhelpingkeepthedangerawayfromtheuser.Alabwilloftenincludeafumehood,abiosafetycabinet,orasimilardevicespecificallydesignedtoallowthesafehandlingofdangerouschemicalsortoxicsubstancesandlimittheriskofcontamination.Insomecases,alabmayrequireequipmentsuchasagloveboxtomaintainaverycleanandsterileenvironment.Diagram1:BiosafetyCabinetandLabHoodsPrimeraLabVentilationSystems4III.UnderPressureStandardventilationdesigntypicallydefinespositiveornegativepressuresrelativetoambient(outdoor)conditions.However,foralab,eachlabspacemustbedefinedatapositiveornegativepressurerelativetotheadjacentareas.Butwhenshouldalabbepositive,negative,orneutralpressuretoadjacentareas?Theanswerdependsonthefunctionoftheroomandthetypeoflab.Labventilationmayhavemultiplelevelsofpressurecontrol.Intheexamplebelow,RoomAispositivepressurecomparedtoCorridorC,whileRoomBisnegativetoCorridorC.Inthiscase,thepressuredifferencesma...
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