ASHRAE.HandBook_29-2007 VENTILATION OF THE INDUSTRIAL ENVIRONMENT

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1、RelatedCommercialResourcesCHAPTER29VENTILATIONOFTHEINDUSTRIALENVIRONMENTVentilationDesignPrinciples.......................................................................................................29.1GeneralComfortandDilutionVentilation.......................................................

2、............................29.2HeatControl..................................................................................................................................29.4EnergyConservationandRecovery...........................................................................................

3、....29.6NDUSTRIALenvironmentsrequireventilationtoreduceexpo-guidelines.Thestandardlevelsformostchemicalandheatexpo-Isuretoexcessheatandcontaminantsthataregeneratedinthesuresaretime-weightedaveragesthatallowexcursionsabovetheworkplace;insomesituations,coolingmayalsoberequired.Venti-limitaslongasth

4、eyarebalancedbyequivalentexcursionsbelowlationisprimarilyusedtocontrolexcessheat,odors,andhazardousthelimitduringtheworkday.However,exposurelevelstandardsparticulateandchemicalcontaminantsthatcouldaffectthehealthforheatandcontaminantsarenotlinesofdemarcationbetweenandsafetyofindustrialworkersor,i

5、nsomecases,beignitedorsafeandunsafeexposures.Rather,theyrepresentconditionstobecomecombustiblewhenallowedtoaccumulatebeyondtheirwhichitisbelievednearlyallworkersmaybeexposeddayafterlowerflammablelimit(LFL).Excessheatandcontaminantscandaywithoutadverseeffects(ACGIH2006a).Becauseasmallbestbecontrol

6、ledbyusinglocalexhaustsystemswheneverpossi-percentageofworkersmaybeoverlystressedatexposurelevelsble.Localexhaustsystemsexhaustheatedairandcontaminantsatbelowthestandards,itisprudenttodesignforexposurelevelsthesourceoftheheatandcontaminantsandmayrequirelowerair-belowthelimits.flowsthangeneral(dil

7、ution)ventilation.Formoreinformation,seeInthecaseofexposuretotoxicchemicals,thenumberofcon-Chapter30.taminantsources,theirgenerationrates,andtheeffectivenessofGeneralventilationcanbeprovidedbymechanical(fan)systems,exh