INSTALLATION INSTRUCTIONS
DUCT PIECES
EQUIVALENT
LENGTH
X NUMBER
USED
= EQUIVALENT
LENGTH
Rectangular
to round
transition
adapter
5 ft
X ( ) =
ft
Wall cap
40 ft
X ( ) =
ft
Round 90
°
elbow
10 ft
X ( ) =
ft
Round 45
°
elbow
5 ft
X ( ) =
ft
Rectangular
90
°
elbow
25 ft
X ( ) =
ft
Rectangular
45
°
elbow
5 ft
X ( ) =
ft
Roof cap
24 ft
X ( ) =
ft
Straight duct
6” round or
3 1/4” x 10”
rectangular
1 ft
X ( ) =
ft
TOTAL LENGTH
=
ft
DUCT LENGTH CALCULATOR
Use the chart below to calculate the total length of the duct work being
installed. The total length should not exceed 140 feet.
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