Carrier 58MXA - Filter Arrangement; Bottom Closure Panel

Step 5—Filter Arrangement
Never operate unit without a filter or with blower access
panel removed.
Factory-supplied washable framed filters are shipped in blower
compartment. Determine location for filter and relocate filter
retaining wire if necessary. See Table 1 to determine correct filter
size for desired filter location. Table 1 indicates filter size,
location, and quantity shipped with this furnace. See Fig. 2 for
location and size of bottom and side return-air openings.
Air delivery above 1800 CFM requires that both sides, a
combination of 1 side and bottom, or bottom only of furnace
be used for return air.
NOTE: Side return-air openings can ONLY be used in UPFLOW
configurations. Install filter(s) as shown in Fig. 18.
Bottom return-air opening may be used with all 4 orientations.
Filter may need to be cut to fit some furnace widths. Install filter
as shown in Fig. 19.
NOTE: Remove and discard bottom closure panel when bottom
inlet is used.
Step 6—Bottom Closure Panel
These furnaces are shipped with bottom enclosure panel installed
in bottom return-air opening. This panel MUST be in place when
side return air is used.
To remove bottom closure panel, perform following:
1. Tilt or raise furnace and remove 2 screws holding front filler
panel. (See Fig. 20.)
2. Rotate front filler panel downward to release holding tabs.
3. Remove bottom closure panel.
4. Reinstall front filler panel and screws.
Table 1—Filter Information
FURNACE
CASING
WIDTH (IN.)
FILTER SIZE (IN.)*
FILTER TYPE
FRAMED
Side Return Bottom Return
17-1/2 (1) 16 X 25 X 1† (1) 16 X 25 X 1 Cleanable
21 (1) 16 X 25 X 1 (1) 20 X 25 X 1† Cleanable
24-1/2 (2) 16 X 25 X 1† (1) 24 X 25 X 1 Cleanable
* Filters can be field modified by cutting frame as marked and folding to desired
size. Alternate sizes can be ordered from your distributor or dealer.
† Factory-provided with furnace.
Fig. 18—Filter Installed for Side Inlet
FILTER
RETAINER
WASHABLE
FILTER
A93045
Fig. 19—Bottom Filter Arrangement
A96030
WASHABLE
FILTER
FILTER
SUPPORT
FILTER
RETAINER
24
1
⁄2-IN. WIDE 
CASINGS ONLY:
CUT AND FOLD
FACTORY-PROVIDED
FILTERS AS SHOWN
TO DESIRED SIZE.
17
1
⁄2-IN. WIDE 
CASINGS ONLY:
INSTALL FIELD-SUPPLIED
FILTER FILLER STRIP
UNDER FILTER.
1″
24
1
/
2
″
3″
Fig. 20—Removing Bottom Closure Panel
A93047
BOTTOM
CLOSURE
PANEL
FRONT FILLER
PANEL
15