5
Downflow Application
Installation Considerations
•
No downflow sub-base is required with this air
handler, however, local codes may require the use
of a non-combustible sub-base when used with
electric heater kit.
•
An “L” or “T” shaped duct enclosure MUST be used
as a supply plenum. No registers or outlets SHALL be
located directly below the air handler supply outlet.
• Size and frame the floor opening as shown in Figure 5.
Refer to the Dimension drawing on page 10. Care
MUST be taken not to overcut the floor opening.
• Caulk around the floor opening with a non-
flammable caulk such as silicone. Set the air handler
in place and secure the air handler properly.
• Allow access to the low voltage connection by
building the platform so that there is a minimum of
51/2" between the floor and the unit flange.
Return Air Filter Clearance
On downflow applications, certain coil models will
protrude from the top of the air handler (coils greater
than 15" tall on A24 through A36 air handlers and coils
greater than 18" on A42 through A60 air handlers). On
these models, the return air filter may be removed and
a separate filter grille may be installed for closet
applications.
If this method is not desirable, cabinet extension kit No.
65-1647 for A24, A30, and A36; or No.65-1649 for A42,
A48, and A60 may be ordered. The extension kit screws
to the side of the air handler and extends the length of
the air handler coil cabinet. In addition, the kit includes
a filter compartment and door.
Emergency Drain Opening
The indoor coil emergency drain opening must be used
for this application. Refer to page 8 for instructions on
condensate tubing.
1. Remove coil access door.
2. Slide coil out of air handler.
3. Remove coil rack from air handler by removing
screws from side of air handler.
4. Relocate rack in air handler as shown in Figure 4
using screws from side of air handler.
5. Turn air handler into downflow position.
6. Slide refrigerant coil into air handler.
7. Reverse and replace air handler door(s).
Relocating Coil
Remove the three
screws on both sides.
Flip over and replace
in new position using
pre-punched holes.
UPFLOW
POSITION
SUPPLY
OPENING
RACK
POSITION
FILTER
DOOR
DOWNFLOW
POSITION
SUPPLY
OPENING
FILTER
DOOR
Relocating Coil for Downflow Position
UNIT
FLANGE
5 1/2”
FLOOR
FLOOR
PLENUM
AIR HANDLER
2 X 6 BOTH
SIDES AND BACK
11
4
11
5
Supply Plenum Floor Opening
CAUTION
The coil MUST be relocated for downflow
application.
