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- Always keep ducts clean to ensure proper air flow.
- It is recommended that the range hood be vented vertically through
the roof through 15 cm (6 in.) round metal/aluminium vent work. The
size of the vent should be uniform.
- Use no more than three 90
degree elbows. Do not install two elbows
together.
- Make sure there are a minimum of 61 cm (24 in.) of straight vent
between the elbows if more than one elbow is used. The length of the
vent system and number of elbows should be kept to a minimum for
effective performance.
- The vent system must have a damper. If roof or wall cap has a damper,
Do not use damper supplied with the range hood.
- Use duct tape to seal all joints in the vent system.
- Fasten all connections with sheet metal screws and tape all joints with
certified Silver Tape or Duct Tape.
Calculate the duct run length:
If ducted with the required minimum of 15 cm (6 in.) round duct work, the
duct run should not exceed 10.7 m (35 ft.). Calculate the length of the
duct work by adding the equivalent feet as below for each piece of duct
in the system.
If you must elbow right away, do it as far away from the hood’s exhaust
opening as possible.
45
o
Elbow
91.4 cm (36 in.)
90
o
Elbow
1.52 m (60 in.)
90
o
Flat Elbow
3.66 m (144 in.)
Wall Cap
0 cm (0 in.)
2.74 m (9 ft.) Straight Duct
2.74 m (108 in.)
2-90
o
Elbow
3.05 m (120 in.)
Wall Cap
0 cm (0 in.)
Total System
5.79 m (228 in.)
