32
*Minimum filter area dictated by heating airflow requirement.
Upright Installations
Depending on the installation and/or customer preference, filters
can be installed in the central return register or a side panel
external filter rack kit (upflows). As an alternative, a media air filter
or electronic air cleaner can be used as the requested filter.
The following illustrations show possible filter locations.
Filter Locations—Possible Upright Upflow
Filter Locations—Possible Upright Counterflow
Horizontal Installations
Filters must be installed in either the central return register or in
the return air ductwork.
Minimum Filter Requirements Chart
Upflow—Cooling Airflow Requirement (CFM)—Permanent Minimum Filter Area (sq. in.) Based On 600 ft (182.9 m) Per
Minute Filter Face Velocity
Input Airflow
600
800
1,000
1,200
1,400
1,600
2,000
0453
376*
384
480
576
-
-
-
0704
-
-
627*
627*
672
768
-
0905
-
-
-
836*
836*
836*
960
1155
-
-
-
940*
940*
940*
960
Counterflow—Cooling Airflow Requirement (CFM)—Permanent Minimum Filter Area (sq. in.) Based On 600 ft (182.9 m)
Per Minute Filter Face Velocity
0704
-
-
320*
320*
336
384
-
0905
-
-
-
427*
427*
427*
480
A. Central return grille
B. Filter
C. Airflow
D. Side return external filter rack kit (either side)
A
B
C
D
B
A. Filter access door
B. Filter
C. Central return grille
D. Airflow
E. Filter support bracket (provided)
F. Return duct
A
B
B
B
C
F
E
D