Venting Requirements
■Vent system must terminate to the outdoors.
■Do not terminate the vent system in an attic or other enclosed area.
■Do not use 4" (10.2 cm)
■Use metal vent only. Rigid metal vent is recommended. Plastic or metal foil vent is not recommended.
■The length of vent system and number of elbows should be kept to a minimum to provide efficient performance.
For the most efficient and quiet operation:
■Use no more than three 90° elbows.
■Make sure there is a minimum of 24" (61.0 cm) of straight vent between the elbows if more than 1 elbow is used.
■Do not install 2 elbows together.
■Use clamps to seal all joints in the vent system.
■The vent system must have a damper. If the roof or wall cap has a damper, do not use the damper supplied with the range hood.
■Use caulking to seal exterior wall or roof opening around the cap.
■The size of the vent should be uniform.
Cold weather installations
An additional back draft damper should be installed to minimize backward cold air flow and a thermal break should be installed to minimize conduction of outside temperatures as part of the vent system. The damper should be on the cold air side of the thermal break.
The break should be as close as possible to where the vent system enters the heated portion of the house.
Makeup air
Local building codes may require the use of makeup air systems when using ventilation systems greater than specified CFM of air movement. The specified CFM varies from locale to locale.
Consult your HVAC professional for specific requirements in your area.
Venting Methods
Calculating Vent System Length
To calculate the length of the system you need, add the equivalent feet (meters) for each vent piece used in the system.
Vent Piece | Equivalent Length |
45° elbow | 2.5 ft |
| (0.8 m) |
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90° elbow | 5.0 ft |
| (1.5 m) |
The maximum equivalent vent lengths are:
10" (25.4 cm) round vents - 60 ft (18.3 m)
Example vent system
90 elbow |
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2ft
(0.6 m)
The following example falls within the maximum recommended vent length.
1 | - 90° elbow | = 5.0 ft (1.5 m) |
1 | - wall cap | = 0.0 ft (0.0 m) |
8 ft (2.4 m) straight | = 8.0 ft (2.4 m) | |
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Length of system | = 13.0 ft (3.9 m) | |
A 10" (25.4 cm) round vent system is needed for installation (not included). The hood exhaust opening is 10" (25.4 cm) round.
NOTE: Flexible vent is not recommended. Flexible vent creates back pressure and air turbulence that greatly reduce performance.
Vent system can terminate either through the roof or wall.
Roof Venting | Wall Venting |
A
B* 
B*
A
A. Roof cap | A. Wall cap |
B. 10" (25.4 cm) round vent* | B. 10" (25.4 cm) round vent* |
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