4
Figure 2. Minimum Unit Clearances
Figure 3. Return and Supply Air Fittings Figure 4. Return Air Box
14” Duct Dimples
Transition Duct Screws
Supply Air
Return Air
3. INSTALL THE RETURN AND SUPPLY AIR
FITTINGS ON THE UNIT
The supply and return fi ttings are included with
select models. If supplied, the duct fi ttings are
shipped in the supply duct. They attach to the unit
openings with a fl ange and bead arrangement,
secured with two sheet metal screws. Note: For
ease of access, install fi tting before positioning
unit in fi nal location.
SUPPLY DUCT
Position the supply duct collar, if supplied, so the
edge of the unit opening fi ts between the fl ange
and the bead. Overlap the collar ends keeping the
small screw holes underneath. Align the holes in
the crimped area and install one screw.
Note: It may be necessary to loosen the four
screws that hold the transition duct in order to
install the supply fi tting. Re-tighten when instal-
lation is complete.
Tap collar as necessary to ensure engagement
with unit opening and install second screw.
Tighten fi rst screw. Rotate collar clockwise so
joint is near three o’clock position.
RETURN DUCT
Align the 14” return duct slots with the holes in
the collar and install two screws. Position the
collar over the opening and align the four notches
in the collar with the four dimples in the panel.
Using self-drilling screws (10-16x.5) attach the
collar to the rear panel.
4. LOCATING AND INSTALLING THE RE-
TURN AIR ASSEMBLY
To avoid complications, locate and install the
return air assembly fi rst. The return air box
with grille and fi lter (Figure 4) should not be
located in heavy traffi c areas like hallways or
center of rooms. A good spot is in a corner or
under a table, if a minimum two inch clearance
is available. If desired, the return opening can
be located inside a closet with louvered doors
that have an open area equal to or greater than
the 12” x 20” grille furnished. The return air grille
can be placed in the wall of a closet and the air
ducted into the fi lter box through a boxed-in area
at the closet fl oor level. Make sure the fi lter is
readily accessible.
After determining the location of the return air
opening, start the installation from under the
home by cutting a small hole in the fi ber under-
board to determine how the fl oor joist location
will affect cutting the opening needed for the box.
Floor joists generally are located on 16” centers,
leaving 14-3/8” between joists. After measuring
the return air box (approximately 12-1/4” x 14-
1/4”), cut the hole through the fl oor so that the
box will fi t between the fl oor joists. Care should
be taken when cutting through carpeting to avoid
snags. In most installations it will be necessary to
cut a similar hole in the fi berboard directly under
the hole in the fl oor. However, if the fl oor is more
6 ft.
24"
12"
12"
