Page 10
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
Bottom Cap
FIGURE 10 
Installation Clearances
Top
Bottom
Left
End
Right
End
AIR FLOW
Vent Connector
Type
Type C Type B1
Top 1 1
*Front 2-1/4 in. (57 mm)** 2-14 in. (57 mm)
Back 1 1
Ends 2 in. (51 mm) 2 in. (51 mm)
Vent 6 in. (152 mm) 1 in. (25 mm)
Floor 1‡ 1‡
*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 
Horizontal Applications
The  EL180UHNE  furnace  can  be  installed  in  horizontal 
applications.  Order  horizontal  suspension  kit  (51W10) 
from Lennox, or use equivalent suspension method.
Allow for clearances to combustible materials as indicated 
on the unit nameplate. Minimum clearances for closet or 
alcove 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 
oor 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
Bracket
Bottom Cap
Metal Strap
3/16 inch
Air Flow
FIGURE 12 
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 ple-
nums 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 fur-
nace installed  in a  horizontal application. The furnace is 
equipped with a removable bottom panel to facilitate in-
stallation. See gure 10.