Lennox ML180DF045P24A - Page 8

Page 8
Downow Installation
Downow unit installs in three ways: on non-combustible
ooring, on combustible ooring using a downow com-
bustible ooring base, or on a reverse-ow cooling cabi-
net. Do not drag the unit across the oor.
Installation on Non-Combustible Flooring (Figure 6)
1 - Cut oor opening keeping in mind clearances listed
on unit rating plate. Also keep in mind gas supply
connections, electrical supply, ue and air intake
connections and sufcient installation and servicing
clearances. See table 1 for correct oor opening
size.
2 - Flange warm air plenum and lower the plenum into
the opening.
3 - Set the unit over the plenum and seal the plenum
to the unit.
4 - Ensure that the seal is adequate.
SUPPLY AIR
PLENUM
OPENING
FIGURE 6
TABLE 1
NON-COMBUSTIBLE FLOOR OPENING SIZE
Cabinet
Width
Front to Rear Side to Side
in mm in mm
A (14.5”)
19-3/4 502
13-1/4 337
B (17.5”) 16-3/4 413
C (21”) 19-3/4 502
NOTE - Floor opening dimensions listed are 1/4 inch (6 mm) larger than
the unit opening. See unit dimensions on page 2.
Installation on Combustible Flooring (Figure 7)
1 - When unit is installed on a combustible oor,
a downow combustible ooring base must be
installed between the furnace and the oor. The
base must be ordered separately.
See table 2 for opening size to cut in oor.
CAUTION
The furnace and downow combustible ooring base
shall not be installed directly on carpeting, tile, or other
combustible material other than wood ooring.
SUPPLY AIR PLENUM
DOWNFLOW
COMBUSTIBLE
FLOORING BASE
PROPERLY
SIZED FLOOR
OPENING
FIGURE 7
TABLE 2
COMBUSTIBLE FLOOR OPENING SIZE
Cabinet
Width
Front to Rear Side to Side
in mm in mm
A (14.5”)
22 569
15-3/4 400
B (17.5”) 18-3/4 476
C (21”) 22-3/4
578
2 - After opening is cut, set combustible ooring base
into opening.
3 - Check sealing strips on combustible ooring base to
make sure they are properly glued and positioned.
4 - Lower supply air plenum into downow combustible
ooring base until plenum anges seal against the
strips.
NOTE - Be careful not to damage sealing strips.
Check for a tight seal.
5 - Set the furnace over the plenum.
6 - Ensure that the seal between the furnace and
plenum s adequate.
Installation on Cooling Cabinet (Figure 8)
1 - Refer to reverse-ow coil installation instructions for
correctly sized opening in oor and installation of
cabinet.
NOTE - Downow combustible ooring kit is not
used.
2 - When cooling cabinet is in place, set and secure
the furnace according to the instructions that are
provided with the cooling coil. Secure the furnace
to the cabinet.
3 - Seal the cabinet and check for air leaks.