4
AIR FLOW
NOT TO EXCEED 20
FURNACE
OPENING
FURNACE AIR CLEANER DUCTWORK
AIR FLOW
THIS CABINET
CAN ACCEPT
ELECTRONIC
AIR CLEANER
OPTION
(SEE PAGE 7)
AIR CLEANER
OPENING
TRANSITION SECTION (IF NEEDED)
Figure 3
Figure 4

LOCATING THE AIR FILTER

Your air filter must be mounted in the return air duct of a
central forced-air system, on the air entering side of your
furnace. (See Figure 3 for example.)
Select a location that meets the following:
1. The face of the filter will be at a right angle to the air
stream.
2. Allow 25” of clearance in front of the air filter compart-
ment door to permit removal of filters.
See figure 4 for complete compartment dimen-
sions.
3. The air filter is not to be placed in the discharge of
either the heating or cooling unit.
4. IMPORTANT: If atomizing spray type humidifier is
used, it must be installed downstream from the air
filter.
If furnace opening cannot be enlarged to required size, a
transition sheet metal section must be used. Transition
must be planned for each job. Reduction should not be
more than 4 inches per linear foot, approximately 20
angular degrees (Figure 3).
PREINSTALLATION
Model No. A B C D E
ACB/ACM1000 20-1/4 12-5/8 13-9/16 16-7/16 19-1/16
ACB/ACM1400 26-1/4 23-5/8 13-9/16 16-7/16 19-1/16
ACB/ACM1600 20-1/4 12-5/8 17-3/4 20-5/8 23-3/8
ACB/ACM2000 26-1/4 23-5/8 17-3/4 20-5/8 23-3/8