Calculating Vent System Length; Venting Methods - CombiSteel 7227.0005 Mode D'emploi

Calculating vent system length

To calculate the length of the system you need, deduct the equivalent feet for each vent piece used in the system
from the recommended maximum duct run.
Duct Run Calculation
Recommended maximum run
8" or 3-1/4 x 10" duct
Each 90º elbow used
Each 45º elbow used
Each 7" to 3/14 x 10" transition used
Side wall cap with damper
Roof cap
Duct Run Calculation example:
One roof cap, two 90º elbow, and one 45º elbow used:
0ft + 9ft + 9ft + 5ft = 23ft used.
Deduct 23ft from 50ft, 27ft maximum available for straight duct run.

Venting methods

•
This range hood is factory set for venting
through the roof or wall.
•
Vent work can terminate either through
the roof or wall. To vent through a wall, a
90° elbow is needed.
IMPORTANT:
•
NEVER exhaust air or terminate duct
work into spaces between walls, crawl
spaces, ceiling,
All exhaust must be ducted to the
outside.
•
Use metal/aluminum duct work only.
•
Fasten all connections with sheet metal
screws and tape all joints with certified
Silver Tape or Duct Tape.
•
Use caulking to seal exterior wall or roof
opening around the cap.
50 ft
Vent piece deduction
9 ft
5 ft
7 ft
0 ft
0 ft
attics or garages.
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