12
18-CD33D1-4
Installer’s Guide
RETURN AIR FILTERS FOR UPFLOW FURNACE IN
HORIZONTAL CONFIGURATION
When the Upflow Furnace is installed in the horizontal
configuration, the return air filters must be installed ex-
terior to the furnace cabinet. Remote filter grilles may be
used for homeowner convenience or the filters may be
installed in the duct work upstream of the furnace. See
Figure 17.
Conversion kits for horizontal filters are BAYFLTR203 for
17 1/2" width cabinets, BAYFLTR204 for 21" width cabi-
nets, and BAYFLTR205 for 24" width cabinets. These in-
clude filters and brackets necessary for horizontal filters.
See Figure 19, Downflow/Horizontal.
ALTERNATE FILTER RACK INSTALLATION FOR SIDE
RETURN AIR ON UPFLOW FURNACES (Left or Right)
BAYRACK960
The following checklist should be used when installing a
right or left side return filter on an upflow furnace:
a. Remove the filter.
b. Leave the bottom panel in place.
c. Make side cutout by following the directions in the
“Return Air Duct Connections” section on page 10.
d. Compress the filter rack and reinstall in the side
position on the furnace. Confirm that the upper
retaining pin/screw locks into the engagement
hole in the blower deck and the lower pin/screw
rests against the side of the bottom panel. See
Figures 13-16.
e. Reinstall the furnace filter in the side position by
inserting the chamfer end first into the filter rack.
RETAINING
PIN
(Both Sides)
SPRINGS
SIDE
CUTOUT
FILTER
RACK
RAILS
BOTTOM
PANEL
INSTALLED
Airflo
w
r
Typical Upflow Right Side Return Filter Rack Installation
RETAINING
PIN
(Both Sides)
SPRINGS
SIDE
CUTOUT
FILTER
RACK
RAILS
BOTTOM
PANEL
INSTALLED
Airflo
w
Typical Upflow Left Side Return Filter Rack Installation
e
BLOWER
DECK
Filter
Rack
Assembly
Furnace
Blower
Deck
Filter Rack
Retaining
Screw/Pin
Engagement Hole
For
Return
Filter Rack
Installation With
Side
Furnace
Cabinet
Side
u
Typical Horizontal Filter Installation
Airflo
w
t
y
Bottom Panel
Filter
Rack
Furnace
Cabinet
Side
Filter Rack
Retaining
Screw/Pin
Engagement Hole
For
Bottom Return
Filter Rack
Installation With
Accessory filter kit
BAYFLTR203, 204, or
205 used for Upflow
Horizontal furnaces
