SystemAir Danvent TIME - I.2.8 Fitting the Ductwork; I.2.9 Risk of Stack Effect by Vertical Ducts and Wind Pressure on Louvers; I.2.10 Refitting of Guards

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i.2.8Fittingtheductwork
FlexibleductconnectionsbetweenAHUandductworkmustalwaysbeinstalled.Besurethatflexibleduct
connectionsarealmostfullystretched.(Flexibleconnectionsareorderedasaccessoriesandtheyareplaced
insidetheunit).Atthefanoutletonacentrifugalfan,theductsizeshouldbeascloseto
theoutletsizeas
possible.Avoidblockageandturbulenceatthefanoutlet.
i.2.9Riskofstackeffectbyverticalductsandwindpressureonlouvers
Onspecialoccasionsstackeffect–alsocalledchimneyeffect–intheductscreateairflowsthatdrivesthe
impellersbyturnedoffmotors.
Arotatingimpellerisapotentialhazardduringcleaningandmaintenanceoftheunit.
Eliminatethisairflowbydamperswithspringreturnmotorsforautomaticclosingof
thedampers‐evenby
powerfailure.
Important!TheSystemairairhandlingunitscanbeorderedanddeliveredwithoutdampers,andthe
installer/usermustcheckthatductsystemswiththedescribedriskofstackeffect(chimneyeffect)willbe
providedwithdampersandspringreturnmotors.
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i.2.10Refittingofguards
Theguardisasafetyguardinstalledinsidethedoor.Toolsarenecessaryfortheremovaloftheguard.Ifthe
guardhasbeendemountedduringtheinstallationonthesite,theguardmustberefittedbeforestartupof
theunit.
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