Owner`s manual

Installation Preparation
DUCT FITTINGS
Use this chart to compute
maximum 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
extended 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 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.
Duct Piece Dimensions
Round.
straight
3-1/4" x 10"
straight
90° elbow
Equivalent
Length*
1 ft. (per
foot length)
1 ft. (per
foot length)
12 ft.
Quantity
Used
45° elbow 7 ft.
3-1/4" x 10" 14 ft.
3-1/4" x 12" 10 ft.
90 ° elbow
3-1/4" x 10" 8 ft.
3-1/4" x 12" 6 ft.
45 ° elbow
---_ 3-1/4" x 10" 33 ft.
3-1/4" x 12" 24 ft.
90° flat elbow
6" round to 2 ft.
rectangular
_,, Rectangular to 8" 2 ft.
round
3-1/4" x 10" 4 ft.
3-1/4" x 12" 4 ft.
6" round to rectangular
transition 90° elbow
3-1/4" x 10" 4 ft.
3-1/4" x 12" 4 ft.
Rectangular to 6" round
transition 90° elbow
Round wall cap
with damper
24 ft.
3-1/4" x 10" 24 ft.
3-1/4" x &2" 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 Evaluation
Engineering and reflect requirements for good
venting performance with any ventilation hood.
Total Duct Run,
Total
Equivalent
Length