5
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.
Set the box into the opening and fasten with
screws or nails. Put the fi lter and return air
grille in place.
5. LOCATING AND INSTALLING THE
SUPPLY DAMPER(S)
CAUTION:
When a home is not equipped with a
make-ready kit means must be pro-
vided to prevent simultaneous opera-
tion of the heating and cooling units.
A heat/cool thermostat is available for
this purpose.
When installing this air conditioning
system in conjunction with a furnace,
a damper must be installed in the fur-
nace base assembly to prevent cold
air being discharged around the heat
exchanger. Damage to the heat ex-
changer and asphyxiation may occur
if a damper is not installed.
if the damp
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 fl oor joists and frame members that could
interfere with the installation of the damper or
fl exible 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. The round supply opening
in the slanted side of the damper should face
the side of the home where the air conditioner
is located. To locate the center of the heat duct,
fi rst cut a small hole in the fi berboard below the
duct at the desired location. After locating the
duct center, cut a hole approximately 3/4” larger
than the damper opening in the fi berboard. Cut
a 9-1/8” x 13-1/8” hole in the duct and bend
over all tabs fl at on the inside of the heat duct.
After inserting the damper into the duct, bend
over all tabs fl at on the inside of the heat duct.
Seal the opening between the fi berboard and
damper or fl exible duct.
DUCTING SYSTEM
DUCT REQUIREMENTS
The supply duct system, including the number
and type of registers, will have much more ef-
fect on the performance of an air conditioning
system than any other factor. The duct must be
suffi ciently large to conduct an adequate amount
of air to each register.
THE AIR CONDITIONING OUTPUT OF THE
SYSTEM WILL NOT COOL THE HOME IF THE
AIR IS LOST TO THE OUTSIDE THROUGH
LEAKS IN THE DUCT SYSTEM. ALSO, DUCTS
WHICH ARE COLLAPSED OR RESTRICTED
BY FOREIGN OBJECTS WILL PREVENT
ADEQUATE AIR FLOW.
Note: For highly resistive duct systems it may be
necessary to add an additional return air duct and
or supply to achieve maximum performance and
prevent coil icing and refrigerant fl ood back.
CONNECTING THE RETURN AND SUPPLY
AIR FLEXIBLE DUCTS
a. The supply duct for all units is twelve inches
in diameter. The return duct is 14” diameter
for all air conditioning units.
b. The fl exible ducts can be connected to the
corresponding fi ttings with the clamps pro-
vided with the ducts. Note: All connections
should be leak tight or a loss in cooling
capacity will result.
c. The fl exible ducts may be cut to the required
length, see instructions packed with duct.
Keep all ducts as short and straight as pos-
sible. Avoid sharp bends.
d. Ducts may be spliced with sheet metal
sleeves and clamps. (See Ducting Instal-
lation Accessories below.)
Figure 5. Supply Damper
