SOFFIT
ROUGH-IN
PLATE
MODEL 329
CONTROL
PACK
RANGE
OR
BARBEQUE
MODEL 331
OR
MODEL 332
EXTERIOR
BLOWER
HOOD
10" ROUND
DUCT
MODEL 453 OR MODEL 454
ELBOW TRANSITION
MODEL 421
IN-LINE
BACKDRAFT
DAMPER
ROUGH-IN
PLATE
SOFFIT
HOOD
MODEL 329
CONTROL
PACK
RANGE
OR
BARBEQUE
MODEL 331 OR MODEL 332
EXTERIOR BLOWER
10" ROUND
DUCT
MODEL 423
4½" x 18½"
TO
10" ROUND
TRANSITION
MODEL 421
IN-LINE
BACKDRAFT
DAMPER
ROUGH-IN
PLATE
SOFFIT
HOOD
MODEL 329
CONTROL
PACK
RANGE
OR
BARBEQUE
MODEL 331
OR
MODEL 332
EXTERIOR
BLOWER
10" ROUND
DUCT
MODEL 424
4½" x 18½" TO 10" ROUND
ELBOW TRANSITION
Horizontally
Ducted
(outside wall)
Vertically
Ducted
Horizontally Ducted
(inside wall)
TYPICAL HOOD CONSTRUCTION
Refer to the illustration, below, for the approximate dimensions of
a hood which should surround the control pack.
Note the size of the open area in the top of the hood.
24"
20"-21"
12"
11" x 24"
OPEN AREA
for rough-in plate
TYPICAL INSTALLATIONS
Three of the most typical installations are shown below.
For maximum ventilation efficiency:
• Use only 10” round duct.
• Keep duct as short and straight as possible.
• Use the fewest number of elbows as possible.
TYPICAL SOFFIT CONSTRUCTION
1. The soffit construction must be a minimum of 12” high (to ac-
commodate the duct transition). At least 10” of inside open
area is require (for 10” round duct). Make sure the soffit will
support the weight of the control pack and a hood.
2. Cut a piece of plywood 23½” wide x the depth of the soffit and
the same thickness as the finished drywall material.
3. Using the rough-in plate as a template, cut holes in the ply-
wood for the duct collar and electrical box.
4. Nail the plywood to the soffit.
2
12"
MINIMUM
PLYWOOD
(23½" x soffit depth
x drywall thickness)
SOFFIT
10"
MINIMUM
WALL
STUD
MODEL 331H OR MODEL 332H
EXTERIOR BLOWER
MODEL 329H
CONTROL
PACK
MODEL 329H
CONTROL
PACK
MODEL 331H
OR
MODEL 332H
EXTERIOR
BLOWER
MODEL 331H
OR
MODEL 332H
EXTERIOR
BLOWER
MODEL 329H
CONTROL
PACK
