12 18-CD34D1-5-EN
INSTALLER’S GUIDE
TABLE 5
CABINET
WIDTH
FILTER
SIZE
FILTER BRACKET
LOCATION *
14-1/2"
2 - 14X20X1
12-7/8"
17-1/2"
2 - 16X20X1
14-3/8"
21"
2 - 16X20X1
13-1/8"
24-1/2"
2 - 16X20X1
11-5/8"
* Location dimension is from end of duct to the screw holes for the
bracket.
t
r
Important: When using the supplied high velocity
filters, the filter support base must be installed into
the furnace duct flange prior to ductwork installation.
Remove the brackets from the blower compartment. They are
wrapped in foam and taped to the side of the downflow unit.
Remove the four screws securing the top panel. Save screws.
Slide the top panel forward approximately 1”.
With support tabs facing up, install the filter base by inserting
one end tab into the duct flange at the rear of the furnace.
Slide the top panel back to its original position, engaging the
other end tab in the slot. Replace screws.
Remove
brackets
Screw
locations
Flanges
upward
TABLE 6
CABINET
WIDTH
RETURN
DUCT
WIDTH
FILTER ACCESS
OPENING -
DIMENSION "A"
FILTER
ACCESS
OPENING -
DIMENSION
"B"
14-1/2"
13-1/4"
12"
14"
17-1/2"
16-1/4"
15"
14"
21"
19-3/4"
19-1/2"
14"
24-1/2"
23-1/4"
22"
14"
GENERAL VENTING INSTRUCTIONS
VENT PIPING
These furnaces have been classified as Fan-Assisted Combustion
System, Category I furnaces under the “latest edition” provisions
of ANSI Z21.47 and CAN/CGA 2.3 standards. Category I
furnaces operate with a non-positive vent static pressure and with
a flue loss of not less than 17 percent.
NOTE: If desired, a side wall termination can be accomplished
through the use of an “add-on” draft inducer. The inducer
must be installed according to the inducer manufacturer’s
instructions. Set the barometric pressure relief to achieve
-0.02 inch water column.
NOTE: When the downflow furnace is vented through the
left side of the furnace cabinet using the provided cutout,
Type B vent piping must be used.
Airflo
w
DOWNFLOW/
HORIZONTAL
DOWNFLOW
Airflow
