10
hand seamers to bend flange back and forth until it breaks off. Be
careful of sharp edges. (See Fig. 14)
Bottom Return Air Inlet
These furnaces are shipped with bottom closure panel installed in
bottom return--air opening. Remove and discard this panel when
bottom return air is used. To remove bottom closure panel,
perform the following:
1. Tilt or raise furnace and remove two screws holding bot-
tom filler panel. (See Fig. 9)
2. Rotate bottom filler panel downward to release holding
tabs.
3. Remove bottom closure panel.
4. Reinstall bottom filler panel and screws
PLENUM
OPENING
C
A
B
D
FLOOR
OPENING
A96283
Fig. 11 -- Floor and Plenum Opening Dimensions
DOWNFLOW
SUBBASE
SHEET METAL
PLENUM
FLOOR
OPENING
FURNACE
(OR COIL CASING
WHEN USED)
COMBUSTIBLE
FLOORING
A96285
Fig. 12 -- Furnace, Plenum, and Subbase Installed
on a Combustible Floor
APPROVED
COIL ASSEMBLY
OR
COIL BOX
FURNACE
SHEET METAL
PLENUM
FLOOR
OPENING
COMBUSTIBLE
FLOORING
A08556
Fig. 13 -- Furnace, Plenum, and Coil Assembly or
Coil Box Installed on a Combustible Floor
Table 4 – Opening Dimensions -- In. (mm)
FURNACE
CASING
WIDTH
APPLICATION
PLENUM OPENING
FLOOR OPENING
A
B
C
D
17–1/2
(445)
Upflow Applications on Combustible or Noncombustible Floor-
ing (KGASB subbase not required)
16
(406)
21---5/8
(549)
16---5/8
(422)
22---1/4
(565)
Downflow Applications on Noncombustible Flooring (KGASB
subbase not required)
15---7/8
(403)
19
(483)
16---1/2
(419)
19---5/8
(498)
Downflow applications on combustible flooring (KGASB sub-
base required)
15---1/8
(384)
19
(483)
16---3/4
(425)
20---5/8
(600)
Downflow Applications on Combustible Flooring with CNPV,
CNRV, CAR, or CAP Coil Assembly or KCAKC coil box
(KGASB subbase not required)
15---1/2
(394)
19
(483)
16---1/2
(419)
20
(508)
21
(533)
Upflow Applications on Combustible or Noncombustible Floor-
ing (KGASB subbase not required)
19---1/2
(495)
21---5/8
(549)
20---1/8
(511)
22---1/4
(565)
Downflow Applications on Noncombustible Flooring (KGASB
subbase not required)
19---3/8
(492)
19
(483)
20
(508)
19---5/8
(498)
Downflow applications on combustible flooring (KGASB sub-
base required)
18---5/8
(473)
19
(483)
20---1/4
(514)
20---5/8
(600)
Downflow Applications on Combustible Flooring with CNPV,
CNRV, CAR, or CAP Coil Assembly or KCAKC coil box
(KGASB subbase not required)
19
(483)
19
(483)
20
(508)
20
(508)