GE Island Vent Hood ZV421 ZV541 - Manual (Page 7)

Equivalent Quantity Total
Duct Piece Length* Used Length
Round, 1 ft.
straight (per foot
length)
1 ft.
3-1/4" x 24" (per foot
straight length)
90° elbow 15 ft.
45° elbow 9 ft.
3-1⁄4" x 12" or
3-1/4" x 24"
90° elbow
15 ft.
3-1/4" x 24"
45° elbow
9 ft.
3-1/4" x 24"
90° flat elbow
20 ft.
10" round to
3-1/4" x 24" transition
1 ft.
3-1/4" x 24" to 10"
round transition
5 ft.
10" round
to 3-1/4" x 24"
transition 90° elbow
5 ft.
3-1/4" x 24" to 10"
round transition 90°
15 ft.
elbow
Round
wall cap
with damper
30 ft.
3-1/4" x 24" wall cap
with damper
30 ft.
Round
roof cap
26 ft.
Round
roof vent
24 ft.
7
Advance Planning
DUCT FITTINGS
Use this chart to compute maximum
permissable lengths for duct runs to
outdoors.
Note: Do not exceed maximum permissable
equivalent lengths!
Maximum recommended duct
length for these hoods: 150 equivalent feet
Flexible ducting:
Flexible metal ducting is not
recommended. If it must be used, all
the equivalent feet values in the table
should be doubled. The flexible metal
duct should be straight and smooth
and extended as much as possible.
Semi-rigid flexible duct is preferred
when flexible duct must be used.
Do NOT use flexible plastic ducting.
Total Duct Run
Note: Any home ventilation system, such as a ventilation
hood, may interrupt the proper flow of combustion air and
exhaust required by fireplaces, gas furnaces, gas water
heaters and other naturally vented systems. To minimize
the chance of interruption of such naturally vented systems,
follow the heating equipment manufacturer’s guidelines and
safety standards such as those published by NFPA and
ASHRAE.
* Actual length of straight duct plus duct fitting
equivalent. Equivalent length of duct pieces are
based on actual tests conducted by GE Evaluation
Engineering and reflect requirements for good
venting performance with any ventilation hood.
Hoods Are Equipped
For 10" Round Duct
*Hoods are supplied with a 10"
round transition. A locally
supplied transition is required
for other sizes.
Note: Outlet on top of hood is
8-1/8" x 8".