11
441 01 2101 05
Specifications are subject to change without notice.
Figure 11
−
Furnace, Plenum, and Subbase installed on
a Combustible Floor
DOWNFLOW
SUBBASE
SHEET METAL
PLENUM
FLOOR
OPENING
FURNACE
(OR COIL CASING
WHEN USED)
COMBUSTIBLE
FLOORING
A96285
Figure 12
−
Furnace, Plenum, and Coil or Coil Casing
Installed on a Combustible Floor
APPROVED
COIL ASSEMBLY
OR
COIL BOX
FURNACE
SHEET METAL
PLENUM
FLOOR
OPENING
COMBUSTIBLE
FLOORING
A08556
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(2) screws holding
bottom filler panel. (See Figure 9)
2. Rotate bottom filler panel downward to release holding
tabs.
3. Remove bottom closure panel.
4. Reinstall bottom filler panel and screws.
HORIZONTAL INSTALLATION
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.
Figure 13
−
Floor and Plenum Opening Dimensions
C
A
B
D
A96283
FIRE, EXPLOSION, AND CARBON MONOXIDE
POISONING HAZARD
Failure to follow this warning could result in personal
injury, death, or property damage.
Do not install the furnace on its back or hang furnace
with control compartment facing downward. Safety
control operation will be adversely affected. Never
connect return
−
air ducts to the back of the furnace.
!
WARNING
Suspended Furnace Support
The furnace may be supported under each end with threaded
rod, angle iron or metal plumber’s strap as shown. (See
Figure 15 and Figure 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
two (2) #8 x 3/4
−
in. (19 mm) screw into the side and 2 #8 x
3/4
−
in. (19 mm) screw in the bottom of the furnace casing for
each strap. (See Figure 15 and Figure 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 Figure 2 and Figure 17) For
furnaces with 1
−
in. (25 mm) clearance requirement on side,
set furnace on non
−
combustible blocks, bricks or angle iron.
For crawlspace installations, if the furnace is not suspended
from the floor joists, the ground underneath furnace must be
level and the furnace set on blocks or bricks.
Roll
−
Out Protection
Provide a minimum 17
−
3/4
−
in. x 22
−
in. (451 x 559 mm) piece
of sheet metal for flame roll
−
out protection in front of burner
area for furnaces closer than 12 inches (305 mm) above the