Lennox SIGNATURE SL280UHV Installation Instructions Manual page 11

Removing the Bottom Panel
Remove the two screws that secure the bottom cap to the
furnace. Pivot the bottom cap down to release the bottom
panel. Once the bottom panel has been removed, reinstall
the bottom cap. See figure 10.
Removing the Bottom Panel
Screw
Bottom Panel
FIGURE 10
Horizontal Application
Installation Clearances
Top
Left
End
Bottom
Vent Connector
Type
Top
*Front 2−1/4 in. (57 mm)**
Back
Ends 2 in. (51 mm)
Vent 6 in. (152 mm)
Floor
*Front clearance in alcove installation must be 24 in. (610 mm).
Maintain a minimum of 24 in. (610 mm) for front service access.
** 3−1/4 in. if single wall vent pipe is used.
‡For installations on a combustible floor, do not install the furnace
directly on carpeting, tile or other combustible materials other
than wood flooring.
FIGURE 11
Bottom Cap
Right
End
Type C Type B1
0 0
2−14 in. (57 mm)
0 0
2 in. (51 mm)
1 in. (25 mm)
0‡ 0‡
Horizontal Applications
The SL280UHV furnace can be installed in horizontal ap-
plications. Order kit number 51W10 (or use equivalent)
from Lennox.
Allow for clearances to combustible materials as indicated
on the unit nameplate. Minimum clearances for closet or al-
cove installations are shown in figure 11.
This furnace may be installed in either an attic or a crawl-
space. Either suspend the furnace from roof rafters or
floor joists, as shown in figure 12, or install the furnace on a
platform, as shown in figure 13.
Typical Horizontal Application
Unit Suspended in Attic or Crawlspace
Bottom Cap
NOTE − Heavy−gauge perforated sheet metal straps may
be used to suspend the unit from roof rafters or ceiling
joists. When straps are used to suspend the unit in this
way, support must be provided for both the ends. The
straps must not interfere with the plenum or exhaust pip-
ing installation. Cooling coils and supply and return air
plenums must be supported separately.
NOTE − When the furnace is installed on a platform in a
crawlspace, it must be elevated enough to avoid water
damage and to allow the evaporator coil to drain.
Return Air −− Horizontal Applications
Return air must be brought in through the end of a furnace
installed in a horizontal application. The furnace is
equipped with a removable bottom panel to facilitate
installation. See figure 10.
Page 11
Bracket
Metal Strap
3/16 inch
Air Flow
FIGURE 12