Dacor Millenia DHW301 Installation Instructions Manual - page 7
5
Calculating the Maximum Duct Run Length
Themaximumstraightductlengthforthehoodis50
feet.Foreachelbowandtransitionaddedtotheduct
work,acertainnumberoffeetmustbesubtractedfrom
themaximumstraightlengthtocompensateforwind
resistance.Todeterminethelengththeductworkcannot
exceed,subtractalloftheequivalentlengthsoftheelbows
andtransitionslistedbelowfrom50feet.
Duct Work Equivalent Lengths
DUCT PIECE
SUBTRACT
90°elbow(8”Dia.)
7feet
45°elbow(8”Dia.)
3feet
31/4”x10”to8”round
4foot
Wallcapwithdamper
30feet
Roofcap
30feet
Duct Work Design Tips
Whereverpossible,reducethenumberoftransitions
•
andturnstoasfewsharpanglesaspossible.Two
staggered45°anglesarebetterthanone90°.
Keepturnsasfarawayfromthehoodexhaustas
•
possible,withasmuchspacebetweeneachbendas
possible.
Forbestperformance,useroundductinsteadof
•
rectangular,especiallywhenelbowsarerequired.
Ifmultipleelbowsareused,trytokeepaminimumof
•
24”ofstraightductbetweenthem.
Avoid“S”or“backtoback”configurationsofadjacent
•
elbows.
Inregionswheretheweathergetsextremelycold,
•
thermalbreaks,suchasashortsectionofnon-metallic
duct,shouldbeusedtoavoidindoorheatloss.The
breakshouldbelocatedasclosetothepassthrough
pointtotheoutsideaspossible.
Donotuseflexiblemetalduct.
•
Donot
•
useductworkthatissmallerincross-sectional
areathantherecommendedsizeduct(8”round).
Duct Work Installation
Install all of the duct work, except for the portion that
will be located inside the hood chimney:
Determinetheverticalcenterlinefortherangehood.
1.
Thecenterlineforthehoodisusuallythesameasthe
centerlineoftherangeorcooktop.
Usingapencil,marktheverticalcenterlineonthewall
2.
fromwherethebottomofhoodwillbelocatedtowhere
thetopofthechimneywillbelocated.
Drawahorizontalline24incheslongat90°tothe
3.
verticalcenterlinewherethebottomofthehoodwillbe
located.Theminimumallowabledistancefromthetop
ofthecooktoptothebottomofthehoodis30”.
Installtheductworksothattheconnectiontothehood
4.
willbecenteredonthehood’scenterline.Alsoallow
fora1”clearancebetweentheductworkandthewall
wherethehoodwillbemounted.The1”clearancewill
allowroomforthechimneymountingbracketonthe
ceiling.
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reparIng
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