Amana ACO1860A Owner's Manual page 13

INSTALLATION
STEP 2: PREPARE THE VENTING SYSTEM
STANDARD FITTINGS
NOTE: If the existing duct is round, you must use a rectangular-to-round adapter, with a rectangular 3"
extension duct installed between the damper assembly and the adapter to prevent the exhaust
damper's sticking.
DUCT LENGTH
The total length of the duct system, including straight duct, elbows, transitions, and wall or roof caps must not
exceed the equivalent of 140 feet.
For best performance, do not use more than three 90 degree elbows, and keep length as short as possible.
Below are the standard fittings and their equivalent length in feet.
3 1/4"x10"
to 6"=5ft.
3 1/4"x10" roof
cap=24ft.
3
3 1/4"x10" 90 °
elbow=25ft.
90 ° elbow
= 1Oft.
5
3 1/4"x10"
wall cap
=40ft.
6
45 ° elbow
=5ft.
7
3 1/4"x10"
flat elbow
= 10ft.
Figure 9
To calculate the equivalent length of each ductpiece used, see the examples below.
For 3 1/4"x10" SYSTEMS
3 1/4"x10" _ 6ft. _ wall cap
90 ° elbow \_[_-_ 2ft. I
1-3 1/4" x 10" 90 ° elbow = 25 ft.
1-Wall Cap = 40 ft.
8 feet straight duct = 8 ft.
TOTAL LENGTH = 73 ft.
I
Examples
For 6" ROUND SYSTEMS
90° elbows _--_ 6ft. ---_S wall cap
transi_
1-transition = 5 ft.
2-90 ° elbows = 20 ft.
1-Wall Cap = 40 ft.
8 feet straight = 8 ft.
TOTAL LENGTH = 73 ft.
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