Page 9
G60DF Series
Downflow Installation
Downflow unit installs in three ways: on non−combustible
flooring, on combustible flooring using an additive base, or
on a reverse−flow cooling cabinet. Do not drag the unit
across the floor.
Installation on Non−Combustible Flooring
1 − Cut floor opening keeping in mind clearances listed on
unit rating plate. Also keep in mind gas supply connec-
tions, electrical supply, flue and air intake connections
and sufficient installation and servicing clearances.
See table 1 for correct floor 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.
3 − Ensure that the seal is adequate.
TABLE 1
NON−COMBUSTIBLE FLOOR OPENING SIZE
Model No
Front to Rear
Side to Side
Model No.
in
.
mm
in.
mm
A Cabinet (14.5")
19 − 3/4
502
13 − 1/4
337
B Cabinet (17.5")
19 − 3/4
502
16 − 1/4
413
C Cabinet (21")
19 − 3/4
502
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
1 − When unit is installed on a combustible floor, an addi-
tive base must be installed between the furnace and
the floor. The base must be ordered separately for the
following cabinet sizes:
D
A cabinet 14.5" − # 11M59
D
B cabinet 17.5" − # 11M60
D
C cabinet −21" # 11M61
See table 2 for opening size to cut in floor.
CAUTION
The furnace and additive base shall not be installed
directly on carpeting, tile, or other combustible ma-
terial other than wood flooring.
TABLE 2
ADDITIVE BASE FLOOR OPENING SIZE
Model No
Front to Rear
Side to Side
Model No.
in.
mm
in.
mm
A Cabinet (14.5")
22
559
15 − 3/4
400
B Cabinet (17.5")
22
559
18 − 3/4
476
C Cabinet (21")
22
559
22 − 3/4
578
NOTE − Floor opening dimensions listed are 1/4 inch (6 mm) larger than
unit opening. See unit dimensions on page 2.
2 − After opening is cut, set additive base into opening.
3 − Check fiberglass strips on additive base to make sure
they are properly glued and positioned.
4 − Lower supply air plenum into additive base until ple-
num flanges seal against fiberglass strips.
NOTE − Be careful not to damage fiberglass strips.
Check for a tight seal.
5 − Set the furnace over the plenum.
6 − Ensure that the seal between the furnace and plenum
is adequate.
G60DF(X)UNIT
SUPPLY AIR PLENUM
ADDITIVE BASE
PROPERLY
SIZED FLOOR
OPENING
FIGURE 6
Installation on Cooling Cabinet
1 − Refer to reverse−flow coil installation instructions for
correctly sized opening in floor and installation of cabi-
net.
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.
Return Air Opening −− Downflow Units
The following steps should be taken when installing ple-
num:
1 − Bottom edge of plenum should be flanged with a
hemmed edge (See figure 7).
SECURE FROM
OUTSIDE CABINET
HEMMED EDGE
PLENUM
FIBERGLASS
SEALING STRIP
(Field Provided)
CABINET SIDE PANEL
Side View
FIGURE 7
2 − Fiberglass sealing strips should be used.
3 − In all cases, plenum should be secured to top flanges
of furnace with sheet metal screws.
