Installation Preparation; Duct Fittings - GE Monogram ZV30H Installation Instructions Manual

Installation Preparation
DUCT FITTINGS
Use this chart to compute maxi-
mum permissible lengths
for duct runs to outdoors.
NOTE: Do not exceed maximum
permissible equivalent lengths!
Maximum duct length:
100 foot for range hoods.
Flexible ducting:
If flexible metal ducting is used,
all the equivalent feet values in
the table should be doubled.
The flexible metal duct should
be straight and smooth and ex-
tended us much us possible.
DO NOT use flexible plastic
ducting.
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 heat-
ers and other naturally vented
systems.
To minimize the chance of
interruption of such naturally
vented systems, follow the heat-
ing equipment manufacturer's
guidelines and safety standards
such as those published by
NFPA and ASHRAE.
Duct Piece Dimensions
Round,
straight
%
3-1/4" x 10"
straight
Equivalent
Length*
1 ft. (per
foot length)
1 ft. (per
foot length)
90 ° elbow 12 ft.
Quantity
Used
45 ° elbow 7 ft.
3-i14" x i0"
3-i14" x 12"
90 ° elbow
14 ft.
i0 ft.
3-i/4" x i0" 8 ft.
3-i/4" x 12" 6 ft.
45 ° elbow
3-i/4" x i0" 33 ft.
3-i14" x 12" 24 ft.
90 ° flat elbow
8" round to 2 ft.
rectangular
Rectangular to 8" 2 ft.
round
3-i/4" x i0" 4 ft.
3-i/4" x 12" 4 ft.
8" round to rectangular
transition 90 ° elbow
3-i14" x i0" 4 ft.
3-i14" x 12" 4 ft.
Rectangular to 8" round
transition 90 ° elbow
Round wall cap
with damper
24 ft.
3-i/4" x i0" 24 ft.
3-i14" x 12" 18 ft.
Rectangular wall cap
with damper
Round roof cap 33 ft.
*Actual length of straight duct plus duct fitting
equivalent. Equivalent length of duct pieces are
based on actual tests conducted by GE Evalua-
tion Engineering and reflect requirements for good
venting performance with any ventilation hood.
Total Duct Run,
Total
Equivalent
Length