Supply Duct with Duct
Adapter Installed
Exhaust Duct Installed
Sealant
Step 5 Apply Sealant
Before installing fans, apply a sealant around
the perimeter of the exhaust and supply duct
adapter to isolate the fan and minimize
vibration.
Supply
Ductwork
by Others
Exhaust
Ductwork
by Others
Metal Cover
Equipment
Support
Roof Curb
Exhaust
Supply
1" Inside
Flange
Installation with Optional Combination Extension
Step 1 Roof Opening
Determine the position of the exhaust and
supply duct roof openings. See pgs. 25-27 for
recommended roof opening dimensions. These
sizes can be smaller based on codes and
ductwork sizes.
Step 2 Install Roof Curb and
Equipment Support
Center curb over roof openings and place on
the roof. Level the curb and shim if necessary.
Attach curb to roof and flash in place.
See pgs 25-27 for equipment support locations.
Attach to roof in the same manner as the curb,
remove metal cover, flash to wooden nailer and
reinstall cover.
Step 3 Install Combination
Extension
Install combination extension over curb, use
wood screws to lag in place. Prepunched holes
are provided. Locate extension so the tall
louvered side is over the exhaust opening, as
shown in illustration.
Step 4 Install Ductwork
Exhaust:
Exhaust ductwork must be built in accordance
with NFPA 96 and any local codes. Ductwork
terminating at the fan should be square in
shape or of smooth transition so as not to
affect the fan performance.
Supply:
The chart at left shows the duct sizes
recommended. Good duct practices
should be followed for the remaining
ductwork.
The use of a duct adapter with the supply duct
is strongly recommended to properly align the
ductwork with the supply fan discharge. The
duct adapter is only a guide and is not intended
to be used as support for the ductwork.
Before beginning this installation:
Make sure that there is room to access the unit from all sides.
The inlet must be located at least 10 feet away from any
exhaust vents.
This unit has a 6" clearance tolerance from the rear and a 24”
clearance tolerance from the sides to any combustibles.
A 48” clearance on the burner control side is recommended for
service and removal of the burner.
Units are for outdoor installation only!
5
Recommended Supply
Ductwork Sizes
IG
Duct
Size
Size
100 to 300
18x30
400 to 800
24x40
