Minimum Filter Requirements Chart
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
040_3BXA or
194*
045_3BXA
060_3BXA or
-
070_3BXA
070_4CXA
-
090_4CXA
-
080_5CXA or
-
090_5DXA
100_5DXA or
-
115_5DXA
Cooling Airflow Requirement (CFM)—Permanent Minimum Filter Area (sq. in.) Based On 300 ft (91.4 m) Per
Minute Filter Face Velocity
040_3BXA or
388*
045_3BXA
060_3BXA or
-
070_3BXA
070_4CXA
-
090_4CXA
-
080_5CXA or
-
090_5DXA
100_5DXA or
-
115_5DXA
*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
A
B
D
A. Central return grille
C. Airflow
B. Filter
D. Side return external filter rack kit (either side)
34
800
1,000
194
240
324*
324*
-
291*
-
432*
-
-
-
-
388*
480
647*
647*
-
583*
-
863*
-
-
-
-
C
B
1,200
1,400
288
-
324*
336
291*
336
432*
432*
388*
388*
486*
486*
576
-
647*
672
583*
672
863*
863*
777*
777*
971*
971*
Filter Locations—Possible Upright Counterflow
A
B
F
E
D
A. Filter access door
B. Filter
C. Central return grille
Horizontal Installations
Filters must be installed in either the central return register or in
the return air ductwork.
1,600
2,000
-
-
-
-
384
-
432*
-
388*
480
486*
486*
-
-
-
-
768
-
863*
-
777*
960
971*
971*
B
B
C
D. Airflow
E. Filter support bracket (provided)
F. Return duct