18-CD33D1-4
11
Installer’s Guide
9.
The horizontal installation of the upflow furnace
requires an external filter section. Do NOT use
the bottom return filter within the furnace. Filter
kits are available for horizontal applications.
10. Connect duct work to furnace. See Outline Drawing
for supply and return duct size and location. Flexible
duct con nectors are recommended to connect both
supply and return air ducts to the furnace. If only the
front of the furnace is accessible, it is recommended
that both supply and return air plenums are
removable.
RETURN AIR FILTERS
TYPICAL UPFLOW RETURN
AIR FILTER INSTALLATIONS
furnaces require high velocity type air filters. The filters
may be installed within the furnace blower compartment
for UPFLOW furnaces in either a BOTTOM or SIDE (left
side or right side) return air inlet. Some filters may need
to be trimmed for side or bottom filter use.
UPFLOW FURNACE ONLY
*
SEE OUTLINE DRAWING
FRONT
of Furnace
LOCATING NOTCH-
ES PROVIDED FOR
SIDE RETURN
CUTOUT
0
CUT OUT FOR
SIDE FILTER
BOTTOM FILTER RACK INSTALLATION
Airflow
q
TABLE 3
NOTE: For upflow 5 ton airflow models where the air-
flow requirement exceeds 1800 CFM - Models will re-
quire return air openings and filters on: (1) both sides,
or (2)1 side and the bottom, or (3) just the bottom.
The furnace and the bottom filter rack, BAYRACK960, in-
stallation can be seen in Figure 11.
The furnace filter in the bottom or side configuration can
be removed by simply turning the two latches on the
blower door and tilting the door forward.
ALTERNATE FILTER RACK INSTALLATION FOR
BOTTOM RETURN - BAYRACK960
The following checklist should be used when installing a
bottom return filter on an upflow furnace:
a. Remove the filter.
b. Remove the bottom panel.
c. With the filter removed, the filter rack is com-
pressed and then inserted into the bottom of the
furnace. The retaining screw/pin on each side
inserts into engagement holes at the bottom of the
furnace cabinet side. See Figure 12.
d. Reinstall the furnace filter in the bottom position
by inserting the chamfer end first into the filter rack.
w
Filter
Rack
Furnace
Cabinet
Side
Filter Rack
Retaining
Screw/Pin
Engagement Hole
For
Bottom Return
Filter Rack
Installation With
UPFLOW FURNACE RETURN AIR FILTERS
CABINET
WIDTH
QTY*
CABINET
BOTTOM FIL-
TER
CABINET
SIDE FILTER
14-1/2"
1
14" X 25" X 1"
17-1/2" X 25" X 1"
17-1/2"
1
17" X 25" X 1"
17-1/2" X 25" X 1"
21"
1
20" X 25" X 1"
17-1/2" X 25" X 1"
24-1/2"
1
24" X 25" X 1"
17-1/2" X 25" X 1"
**NOTE: For upflow 5 ton airflow models where the airflow
requirement exceeds 1800 CFM - Models will require return air
openings and filters on: (1) both sides, or (2) one side and the
bottom, or (3) just on the bottom
