FORM 145.26-IOM1 (908)
11
JOHNSON CONTROLS
12. FILTER RACK INSTALLATIONS FOR
SIDE RETURN
CAUTION:Air filters are required to keep
the heating coil, air conditioning coil,
and blower motor clean. A filter frame
has to be field installed, after snipping
out the prepunched opening in the side
of the unit.
Position the three-sided filter frame so that the short side
is towards the back of the furnace and the 1-inch duct
flange is facing outwards. The long sides of the frame
should be pulled slightly towards each other, so that the
continuous slip formed on the back of the frame clears
the opening in the cabinet. Push the frame towards the
back of the unit firmly until the short vertical part of the
frame clips onto the cabinet. Then insert the other verti-
cal side of the frame between the ends of the top and
bottom parts of the frame. This will keep the top and
bottom parts of the frame clipped into position.
If there is difficulty getting the front vertical piece in
-
stalled. Remove the entire filter frame and trim off any
burrs left where the opening was snipped out.
BOTTOM RETURN PLENUMS
When a bottom return plenum is used, snip out the
pre-punched 11 x 20 inch opening in the bottom of the
cabinet. Do not use this opening as a filter size. Bot
-
tom return units are provided with a wire mesh filter
rack, suitable for use with replaceable filter media. The
required media size for this factory provided rack is 24”
x 28” x 1” thick.
If desired, panel filters may be installed in the bottom
return plenum or in the return air duct.
RECOMMENDED FLAT PANEL FILTERS SIZES FOR
BOTTOM RETURN APPLICATION
Unit Size
Filter Size
1 Ton
12” x 20” x 1”
1-1/2 Ton
14” x 20” x 1”
2 Ton
16” x 25” x 1”
2-1/2 Ton
16” x 25” x 1”
There are no filters supplied with this unit. The installing
contractor must provide and install the recommended
size filters.
ALTERNATIVE FILTER ARRANgEMENTS
On 1 and 1 ½ ton units only, a filter frame to hold a 14
x 20 x 1 inch disposable filter may be fitted to the front
of the blower compartment, in place of the access door.
The filter frame and a section of the return duct con
-
nected to it must be easily removable, to allow room for
removal of the blower and motor assembly.
