Typical Upflow/ Horizontal Attic Installation
The Furnace may be placed horizontally in a crawl space on a
pad or other noncombustible material which will raise the
unit for sufficient protection from moisture. The Furnace
must be supported at both ends and the middle when in-
stalled horizontally. The Furnace must also be elevated
approximately 4-6 inches to allow clearance for the con-
densate drain to exit the cabinet in the horizontal posi-
The horizontal Furnace may also be suspended from the
joists using all-thread rods with a substantial metal support
frame that supports the entire length of the furnace. The rods
need to be of sufficient length to allow for proper clearances
from combustible materials. The frame needs to be at least
32" in length to allow for access to service panels.
If the Furnace is suspended using steel strap, it must be sup-
ported at all four corners and in the middle at the front of the
NOTE: No sheetmetal
screws may be used
from 0-4" from the
bottom of the unit.
Screws will interfere
with the air cleaner.
NOTE: Do NOT install screws to the bottom of the
unit except with Duct Flanges and Screws provided.
GUIDE FOR THE INSTALLATION OF DUCT FLANGES
Failure to use pre-drilled holes and the factory
provided screws can potentially damage air cleaner
• Duct Flanges
Two 23.5" Flanges
Two Additional Flanges
15.92" (for 17.5" cabinet)
19.42" (for 21" cabinet)
21.92" (for 24.5" cabinet)
Eight 5/16" Blunt Tip Screws with 5/16" Hex
1. See Figures 5, 6, and 7 for flange orientation.
2. Attach flanges 1, 2, and 3 (Fig 7) to the unit using
the factory provided screws and the pre-drilled
holes in the wrapper. Flanges 1 and 2 are the
23.5" flanges that are generic to all units. Flange
3 will be one of two short flanges and the length
of which is dependent on the cabinet size.
3. Attach flange 4 (Fig 7) to the duct work (Flanges
should be inside duct work). Flange 4 is the
remaining short flange.
4. Place duct work with single flange over the 3
flanges that are currently attached to the unit
5. Attach duct work to remaining 3 flanges.
6. Attach the front flange from step 3 to the unit by
drilling 1/8" holes into the bottom channel. Use
the factory provided 5/16" blunt tip screws to
7. Use field supplied material to make an adequate
seal. DO NOT use silicon based sealant in
Figure 5: Horizontal Left