6
Figure 4. Return Air Box Assembly
1. Start the installation from under the home by cutting a small
hole in the subfloor. Determine how the floor joist location
will affect cutting the opening needed for the return air box.
NOTE: Floor joists are generally located on 16” centers,
leaving 14-3/8” between joists.
2. After measuring the return air box (approximately 12-1/4” x
20-1/4”), cut the hole through the floor so that the box will fit
between the floor joists. Care should be taken when cutting
through carpeting to avoid snags.
NOTE: In most installations
it will be necessary to cut a similar hole in the fiberboard
directly under the hole in the floor. However, if the floor is
more than ten inches deep, it will only be necessary to cut
a hole for the collar on the return air box or for the insulated
duct.
3. Set the box into the opening and fasten with screws or nails.
4. Install the filter and return air grille in the air box.
Locating & Installing the Supply Damper(s)
CAUTION:
If installing this air conditioning system in
conjunction with a furnace, a damper must be
installed in the furnace base assembly to prevent
cold air from being discharged around the heat
exchanger. Damage to the heat exchanger
and asphyxiation may occur if a damper is not
installed.
Check with the furnace manufacturer for damper
requirements. Failure to install the required
furnace damper may invalidate code agency
listing and limited warranty on the furnace.
When locating the supply damper(s), carefully check floor joists
and frame members that could interfere with the installation
of the damper or flexible duct. Ideally, the damper should be
located in the bottom of the main duct, forward of center of the
home, at least three feet from the nearest register. See
. The round supply opening in the slanted side
of the damper should face the side of the home where the air
conditioner is located.
1. Locate the center of the heat duct by cutting a small hole in
the fiberboard below the duct at the desired location.
2. Cut a hole approximately 3/4” larger than the damper opening
in the fiberboard.
3. Cut a 9-1/8” x 13-1/8” hole in the duct and bend over all tabs
flat on the inside of the heat duct.
4. Insert the damper into the duct and bend over all tabs flat on
the inside of the heat duct.
5. Seal the opening between the fiberboard and damper or
flexible duct.
Connecting the Return & Supply Air Flexible Ducts
• Flexible ducts can be connected to the corresponding fittings
with the clamps provided with the ducts. See
NOTE: To prevent a loss in cooling capacity,
make sure all connections are tight.
• The flexible ducts may be cut to the required length, see
instructions packed with duct. Keep all ducts as short and
straight as possible. Avoid sharp bends.
• Ducts may be spliced with sheet metal sleeves and clamps.
• After the inner duct is connected to the proper fitting, the
insulation and plastic sleeve should be pulled over the
connection and clamped.
• Homes with multiple supply ducts (or special applications), a Y
fitting is available to divide the supply air so it can be ducted to
different areas of the home for more efficient cooling.
NOTE:
For maximum performance, insulate the Y fitting.
Condensate Drainage
A 3/4” condensate fitting extends out of the side of the unit
). The drain trap, shipped in the electrical compartment,
must be installed to prevent water from collecting inside the unit.
1. Thread the elbow provided with the unit into the drain
connection until hand tight.
2. Connect the condensate tubing onto the fitting, forming a trap
near the drain connection.
3. Route the condensate tube from the trap to a suitable drain.
NOTE: For proper drainage, make sure the trap is level to
the ground and tubing outlet is below trap level.
Figure 5. Supply Damper
AUTOMATIC DAMPER IS CLOSED
WHEN AC UNIT IS OFF
36” MIN.
REGISTER
Figure 6. Drain Trap
P-Trap
Elbow
