Installation Manual
18 440 01 4800 02
Specifications subject to change without notice.
Table 5 – Opening Dimensions -- In. (mm)
FURNACE
CASING
WIDTH
IN. (mm)
APPLICATION
PLENUM OPENING FLOOR OPENING
A B C D
14–3/16{
(360)
Upflow Applications on Combustible or Noncombustible
Flooring (subbase not required)
12---11/16
(322)
21---5/8
(549)
13---5/16
(338)
22---1/4
(565)
Downflow Applications on Noncombustible Flooring
(subbase not required)
12---9/16
(319)
19
(483)
13---3/16
(335)
19---5/8
(498)
Downflow applications on combustible flooring
(subbase required)
11---13/16
(284)
19
(483)
13---7/16
(341)
20---5/8
(600)
Downflow Applications on Combustible Flooring with coil
assembly or coil box (subbase not required)
12---5/16
(319)
19
(483)
13---5/16
(338)
20
(508)
17–1/2
(445)
Upflow Applications on Combustible or Noncombustible
Flooring (subbase not required)
16
(406)
21---5/8
(549)
16---5/8
(422)
22---1/4
(565)
Downflow Applications on Noncombustible Flooring
(subbase not required)
15---7/8
(403)
19
(483)
16---1/2
(419)
19---5/8
(498)
Downflow applications on combustible flooring
(subbase required)
15---1/8
(384)
19
(483)
16---3/4
(425)
20---5/8
(600)
Downflow Applications on Combustible Flooring with coil
assembly or coil box (subbase not required)
15---1/2
(394)
19
(483)
16---1/2
(419)
20
(508)
21
(533)
Upflow Applications on Combustible or Noncombustible
Flooring (subbase not required)
19---1/2
(495)
21---5/8
(549)
20---1/8
(511)
22---1/4
(565)
Downflow Applications on Noncombustible Flooring
(subbase not required)
19---3/8
(492)
19
(483)
20
(508)
19---5/8
(498)
Downflow applications on combustible flooring
(subbase required)
18---5/8
(473)
19
(483)
20---1/4
(514)
20---5/8
(600)
Downflow Applications on Combustible Flooring with coil
assembly or coil box (subbase not required)
19
(483)
19
(483)
20
(508)
20
(508)
24---1/2
(622)
Upflow Applications on Combustible or Noncombustible
Flooring (subbase not required)
23
(584)
21---1/8
(537)
23---5/8
(600)
22---1/4
(565)
Downflow Applications on Noncombustible Flooring
(subbase not required)
22---7/8
(581)
19
(483)
23---1/2
(597)
19---5/8
(498)
Downflow applications on Combustible flooring
(subbase required)
22---1/8
(562)
19
(483)
23---3/4
(603)
20---5/8
(600)
Downflow Applications on Combustible Flooring with coil
assembly or coil box (subbase not required)
22---1/2
(572)
19
(483)
23---1/2
(597)
20
(508)
* Not all families have these models.
PLENUM
OPENING
C
A
B
D
FLOOR
OPENING
DOWNFLOW
SUBBASE
SHEET METAL
PLENUM
FLOOR
OPENING
FURNACE
(OR COIL CASING
WHEN USED)
COMBUSTIBLE
FLOORING
APPROVED
COIL ASSEMBLY
OR
COIL BOX
FURNACE
SHEET METAL
PLENUM
FLOOR
OPENING
COMBUSTIBLE
FLOORING
A10491
Fig. 25 -- Installation on Combustible Flooring
Connect supply-- air duct to flanges on furnace supply -- air outlet.
Bend flange upward to 90_ with wide duct pliers. See Fig. 20.
The supply--air duct must b e connected to ONLY the furnace
supply--outlet-- air duct flanges or air conditioning coil casing
(when used). DO NOT cut main furnace casing side to attach
supply air duct, humidifier, or other accessories. All supply-- side
accessories MUST be connected to duct external to furnace main
casing.
Return Air Connections
The return--air duct may be connected to bottom of the furnace.
The side of casing that faces downward may also be used for return
air connection. A combination of the bottom and downward
facing side may also be used. The upward facing side of the casing
cannot be used as a return air connection. See Fig. 23.
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 see Fig.
24.