Broan 331H 安装指南

1. Choose a position on the outside wall. Make sure

that no wall studs, pipes or wires run through the
opening area.

2. Drill a guide hole at the center of the opening area.

3. Mark a 25" by 29-1/2" rectangle on wall located

from guide hole as shown in Figure 3.

4. Cut a rectangular hole in the siding only. Do not cut

the sheathing. Nail down all siding ends.

5. Mark an 11" diameter circle centered on the guide

hole and mark the center of the 1-1/4" diameter
electrical wiring hole.

6. Cut the 11" diameter hole in the sheathing and drill

the 1-1/4" hole as marked.

1. Unpack the blower assembly.

2. Remove the cover and screws.

3. Remove and discard cardboard from blower wheel.

4. Remove the wiring box cover and screws.

5. Attach an appropriate U.L. approved cable con-

nector in the hole at the rear of the wiring box.

1. Locate the blower on the rear slope of the roof.

Place it in a location to minimize duct run. The
location should be free of obstacles (T.V. leads,
electrical lines, etc.). Bear in mind, if the blower top
is level with the roof peak, it will not be seen from
the street. Keep this approximate location in mind
as you work from within the attic.

2. Mark a point halfway between rafters.

3. Drill a guide hole through the roof at this point.

4. From the outside, use the guide hole as a starting

point and mark the rectangular cutout and remove
only the shingles in this area. See Figure 1.

5. Mark an 11" diameter circle centered on the guide

hole and mark the center of the 1-1/4" diameter
electrical wiring hole. See Figure 1.

6. Cut out the roof board(s) along the 11" diameter

circle and drill a 1-1/4" hole as marked.

7. For flat roof installations, build a curb that will

mount the blower at a minimum pitch of 2/12. See
Figure 2. Discharge end of the blower should be
pointed away from prevailing winds.