Open as PDF
INSTALL FURNACE DOORS
Install the lower door first by slidingthe bottom of the door
down until the tabs on the casing base engage the slots in the
bottom door end cap. Then push the top of the lower door in
until the door clips snap into place. Install the upper door in a
similarmanner, first engaging the slots in the top of the upper
door on the tabs on the casing top. Then snap the bottom of
the upper door into place against the casing.
FINISH AND TRIM
Alcove and Closet Installations may now be finished and
trimmed as necessary.
NOTE: FOR BEST AIR DELIVERY INSTALL DAMPER
WITH BLADES PARALLEL TO SUPPLY DUCT.
FIGURE 24 : Anti-Backflow Damper
FURNACE AND AIR CONDITIONER
Ifan air conditioner is installed which does not use the blower
for air distribution and operates completely independent of
the furnace, the thermostat system must have an interlock to
prevent the furnace and air conditioner from operating at the
same time. This interlock system usually contains a heat-cool
switch which must be turned to either HEAT or COOL to acti-
vate either heating or cooling operation, or a positive OFF
switch on the cooling thermostat.
When used in connection with a cooling unit the furnace shall
be installed parallel with or on the upstream side of the cool-
ing unit to avoid condensation in the heat exchanger.
For installations with a parallel flow arrangement, the furnace
must be equipped with a damper to prevent cold air from
being discharged up around the heat exchanger. Cold air
causes condensation inside the exchanger and can cause it
to rust out which can allow products of combustion to be cir-
culated into the living area by the furnace blower resulting in
possible asphyxiation. An air flow activated automatic
damper, PIN 7900-6771, is available from furnace manufac-
turer. See Figure 24.
NOTE: See label on coil panel for conversion and lighting
instructions. Obtain a temperature rise within the ranges
specified on the name plate.
20 Unitary Products Group