4. Reinstall bottom filler panel and screws.
HORIZONTAL INSTALLATION
FIRE, EXPLOSION, AND CARBON MONOXIDE
POISONING HAZARD
Failure to follow this warning could result in dangerous
operation, serious injury, death, or property damage.
Do not install the furnace on its back or hang furnace with
control compartment facing downward. Safety control opera-
tion will be adversely affected. Never connect return-air ducts
to the back of the furnace.
The furnace can be installed horizontally in an attic or crawl space
on either the left-hand (LH) or right-hand (RH) side. The furnace
can be hung from floor joists, rafters or trusses or installed on a
non-combustible platform, blocks, bricks or pad.
Suspended Furnace Support
The furnace may be supported under each end with threaded rod,
angle iron or metal plumber’s strap as shown. (See Fig. 15 and 16.)
Secure angle iron to bottom of furnace as shown. Heavy-gauge
sheet metal straps (plumber’s straps) may be used to suspend the
furnace from each bottom corner. To prevent screws from pulling
out, use 2 #8 x ¾-in. screws into the side and 2 #8 x ¾-in. screws
in the bottom of the furnace casing for each strap. (See Fig. 15 and
16.)
If the screws are attached to ONLY the furnace sides and not the
bottom, the straps must be vertical against the furnace sides and
not pull away from the furnace sides, so that the strap attachment
screws are not in tension (are loaded in shear) for reliable support.
Platform Furnace Support
Construct working platform at location where all required furnace
clearances are met. (See Fig. 2 and 17.) For furnaces with 1-in.
clearance requirement on side, set furnace on noncombustible
blocks, bricks or angle iron. For crawl space installations, if the
furnace is not suspended from the floor joists, the ground under-
neath furnace must be level and the furnace set on blocks or bricks.
Roll-Out Protection
Provide a minimum 17-3/4
″
X 22
″
piece of sheet metal for flame
roll-out protection in front of burner area for furnaces closer than
12 inches above the combustible deck or suspended furnaces
closer than 12 inches to joists. The sheet metal MUST extend
underneath the furnace casing by 1 in. with the door removed.
The bottom closure panel on furnaces of widths 17-1/2 in. and
larger may be used for flame roll-out protection when bottom of
furnace is used for return air connection. See Fig. 17 for proper
orientation of roll-out shield.
Table 4—Opening Dimensions (In.)
FURNACE
CASING
WIDTH
APPLICATION
PLENUM OPENING
FLOOR OPENING
A
B
C
D
14–3/16
Upflow Applications on Combustible or Noncombustible
Flooring (KGASB subbase not required)
12-11/16
21-5/8
13-5/16
22-1/4
Downflow Applications on Noncombustible Flooring
(KGASB subbase not required)
12-9/16
19
13-3/16
19-5/8
Downflow applications on combustible flooring (KGASB
subbase required)
11-13/16
19
13-7/16
20-5/8
Downflow Applications on Combustible Flooring with CD5 or
CK5 Coil Assembly or KCAKC coil box (KGASB subbase
not required)
12-5/16
19
13-5/16
20
17–1/2
Upflow Applications on Combustible or Noncombustible
Flooring (KGASB subbase not required)
16
21-5/8
16-5/8
22-1/4
Downflow Applications on Noncombustible Flooring
(KGASB subbase not required)
15-7/8
19
16-1/2
19-5/8
Downflow applications on combustible flooring (KGASB
subbase required)
15-1/8
19
16-3/4
20-5/8
Downflow Applications on Combustible Flooring with CD5 or
CK5 Coil Assembly or KCAKC coil box (KGASB subbase
not required)
15-1/2
19
16-1/2
20
21
Upflow Applications on Combustible or Noncombustible
Flooring (KGASB subbase not required)
19-1/2
21-5/8
20-1/8
22-1/4
Downflow Applications on Noncombustible Flooring
(KGASB subbase not required)
19-3/8
19
20
19-5/8
Downflow applications on combustible flooring (KGASB
subbase required)
18-5/8
19
20-1/4
20-5/8
Downflow Applications on Combustible Flooring with CD5 or
CK5 Coil Assembly or KCAKC coil box (KGASB subbase
not required)
19
19
20
20
24-1/2
Upflow Applications on Combustible or Noncombustible
Flooring (KGASB subbase not required)
23
21-1/8
23-5/8
22-1/4
Downflow Applications on Noncombustible Flooring
(KGASB subbase not required)
22-7/8
19
23-1/2
19-5/8
Downflow applications on Combustible flooring (KGASB
subbase required)
22-1/8
19
23-3/4
20-5/8
Downflow Applications on Combustible Flooring with CD5 or
CK5 Coil Assembly or KCAKC coil box (KGASB subbase
not required)
22-1/2
19
23-1/2
20
12
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