LaboratoryVentilationPolicyPurpose1.Thepurposeofthispolicyis:1.1.Toenableenergy,costandcarbonsavingswhilemaintainingorimprovingsafetyandcompliancewithinUniversityofEdinburghlaboratories1.2.TostandardisegoodpracticeinthedesignandoperationofthevariousventilationsystemswithinUniversityofEdinburghlaboratories.Overview2.Labventilationishighlyenergyintensiveduetotheexpulsionofheatedorcooledairfromthebuilding,requiringfresh‘make-up’airtobeheatedorcooledasitentersthebuilding.Airchangeratesforrooms,andflowratesforlocalisedextractventilation(e.g.fumecupboards,downdraughttables,biologicalsafetycabinets,extractsnorkels,etc.)areamajordeterminantoflabenergyconsumption,andshouldbesetbasedonevidence.Safetyofoccupantsmustbeprioritised,butshouldbeachievedwiththelowestenergyconsumptionpossible.3.Thispolicyseekstoensureprovisionofadequate,flexibleandsafeventilation,includingavoidingoperatingventilationsystemsatafixedratewhichisdesignedtocopewitha‘worst-case-scenario’chemicalspillallthetime.Thisisaninappropriatelycrudeapproachtotheissueofsafeandsustainableventilation,andresultsinunnecessaryconsumptionofenergyandresources.Scope4.Forthepurposesofthispolicy,theterm“laboratory”refersto“wetlabs”butcouldalsoincludeclinicalareas.Thefollowingareasareconsideredwithinthispolicy:4.1.Thefrequencyofairchangesperhour(ACH)generatedbyairhandlingsystemssupplyingairtolaboratoryrooms,andhowtoreachasafeandcomfortableminimumACH.4.2.Thespeed(facevelocityinm/s)andthereforealsovolumeofairbeingdrawnthroughfumecupboards,andhowtoreachasafeminimumfacevelocity.4.3.Thefrequencyofairchangesperhour(ACH)generatedbyairhandlingsystemssupplyingairtoanimalhousingfacilityrooms,andhowtoreachasafeandcompliantminimumACH.4.4.Theuseofindividuallyventilatedcagesinanimalhousingfacilities,andhowthisinteractswithroomventilationsystems.4.5.Thespeed(andcontrolthereof)offumecupboardexhaustairasitexitstheexhauststacks.ThePolicy5.Theoverarchingprinciplesofthepolicyaimtoreducethe‘consumption’ofheatedortreatedairwithinUniversityofEdinburghsciencebuildings,andassociatedenergy,carbonandcostimplications,whilstinnowaycompromisingsafetyandhealth.26.AppropriateventilationshallbeprovidedforeachscenarioacrosstheUniversityofEdinburghinordertodeliverappropriateconditionsforthesafetyandcomfortofoccupantsandeffectiveoperationofequipment.7.Anevidence-basedapproachshouldbeusedtoensureventilationratesshouldbesetastothelowestsafelevel(forbothgenerallabroomventilationandfumecupboardventilation).7.1.Withappropriatelydesignedsillsfumecupboardscanoftenoperatesafelyat0.35m/sfacevelocity.Higherfacevelocitiesmayberequiredforhighlyhazardousmaterialssuchasradio-isotopes.Facevelocitiesshouldbecheckedannuallyandmustbewithin±10%ofthecommissioningvelocity.7.2.Inanon-responsivesystemgenerallabventilationshouldset-backto4airchangesperhour(ACH)outsideofworkinghoursandshouldaimforaslowaspossibletoachievesafetyduringworkinghours.Numerouslabs1haveadopted6ACHwhenoccupied,others8ACH.Evidenceofneedshouldbeprovidedifalabistobeventilatedatarateexceeding12ACH.7.3.Alltasksundertakeninalabshouldberiskassessed(detailsprovidedinsupportingLabVentilationGuidance).Thiswilldeterminethelevelofventilationandcontrolmeasuressuchasfumecupboardsrequiredtoensuretasksareundertakensafely.7.3.1.GuidanceonriskassessmentsisavailableontheHealthandSafetywebsiteathttps://www.ed.ac.uk/health-safe...
