Installation Manual

8
9
Exhaust requiremen
ts
Use this section if you plan to vent your microwave outside (top or back exhaust). If you plan
to recirculate the air back into the room, skip to “Removing your microwave” on page 9.
When installing exhaust vents:
• Use the most direct route with as few elbows/transitions as possible. This helps prevent
blockages and ensures
that the exhaust is being vented correctly.
• Your microwave is designed to mate with a standard 3-1/4” × 10” rectangular duct. If a
round duct is required, a
rectangular-to-round transition adapter must be used. Do not use a duct with a diameter
less than 6”.
• Elbows, transitions, and wall/roof caps add resistance to airflow. Each of these pieces are equivalent to a section
of straight duct that is longer than their actual physical size. When calculating your duct length, add the
equivalent lengths of all the pieces together. For proper airflow, the equivalent airflow should not exceed 120 ft.
For example:
Note
If a rectangular-to-round transition adapter is used, you must cut the bottom
corners of the damper wih tin snips to let the damper have free movement.
Note
Equivalent lengths of duct pieces are based on actual tests and reflect
requirements for good venting performance with any vent hood.
Use the “Equivalent duct length table” on page 9 to calculate
the equivalent duct-work length for your setup.
T
o calculate your equivalent duct length:
1 Write the number of sections used for each of the duct pieces.
2 Multiply the number used by the equivalent length for each duct piece.
3 Add the total equivalent lengths together. This number must be less than 120 ft.
Duct Pieces
Equivalent
Length
× Number Used =
To ta l
Equivalent
Length
5 ft. × ( ) = ft.
40 ft. × ( ) = ft.
10 ft. × ( ) = ft.
5 ft. × ( ) = ft.
25 ft. × ( ) = ft.
5 ft. × ( ) = ft.
24 ft. × ( ) = ft.
1 ft. × ( ) = ft.
Total ductwork =
ft.
(For proper airflow, this
number should not
exceed 120 ft.)
Rectangular-to-
round transition
adapter
Wall cap
90° elbow
45° elbow
90° elbow
45° elbow
Roof cap
Straight duct 6” round
OR
3-1/4” × 10” rectangular
Equiv
alent duct length table