Page 11
CAUTION
If this unit is being installed in a space serviced by an
exhaust fan, power exhaust fan, or other device which
may create a negative pressure in the space, take care
when sizing the inlet air opening. The inlet air opening
must be sized to accommodate the maximum volume
of exhausted air as well as the maximum volume of
combustion air required for all gas appliances serviced
by this space.
Horizontal Application
Unit Installed on Platform
clearances.
GAS
ENTRY
VENT
PIPE
See the unit nameplate for
Line contact is permissible
SERVICE PLATFORM
FIGURE 13
WARNING
Improper installation of the furnace can result in personal
injury or death. Combustion and ue products must
never be allowed to enter the return air system or the
living space. Use screws and joint tape to seal the return
air system to the furnace.
In platform installations with bottom return air, the furnace
should be sealed airtight to the return air plenum. A door
must never be used as a portion of the return air duct
system. The base must provide a stable support and an
airtight seal to the furnace. Allow absolutely no sagging,
cracks, gaps, etc.
The return and supply air duct systems must never be
connected to or from other heating devices such as a
replace or stove, etc. Fire, explosion, carbon monoxide
poisoning, personal injury and/or property damage could
result.
WARNING
The blower access panel must be securely in place when
the blower and burners are operating. Gas fumes, which
could contain carbon monoxide, can be drawn into living
space resulting in personal injury or death.
Filters
This unit is not equipped with a lter or rack. A eld-pro-
vided high-velocity lter is required for the unit to operate
properly. TABLE 1 lists recommended lter sizes.
IMPORTANT
If a higheciency lter is being installed as part of this
system to ensure better indoor air quality, the lter must
be properly sized. Higheciency lters have a higher
static pressure drop than standardeciency glass/foam
lters. If the pressure drop is too great, system capacity
and performance may be reduced. The pressure drop
may also cause the limit to trip more frequently during
the winter and the indoor coil to freeze in the summer,
resulting in an increase in the number of service calls.
Before using any lter with this system, check the
specications provided by the lter manufacturer against
the data given in the appropriate Lennox Product
Specications bulletin. Additional information is provided
in Service and Application Note ACC002 (August 2000).
A lter must be in place any time the unit is operating.
TABLE 1
Furnace Cabinet
Width
Filter Size
Side Return Bottom Return
A - 14-1/2” 16 X 25 X 1 (1) 14 X 25 X 1 (1
B - 17-1/2” 16 X 25 X 1 (1) 16 X 25 X 1 (1)
C - 21” 16 X 25 X 1 (1) 20 X 25 X 1 (1)
Duct System
Use industry-approved standards (such as those pub-
lished by Air Conditioning Contractors of America or Amer-
ican Society of Heating, Refrigerating and Air Conditioning
Engineers) to size and install the supply and return air duct
system. FIGURE 14 shows the correct supply and return
duct installation. This will result in a quiet and low-static
system that has uniform air distribution.
NOTE - Do not operate the furnace in the heating mode
with an external static pressure that exceeds 0.5 inches
w.c. Higher external static pressures may cause erratic
limit operation.
Supply Air Plenum
If the furnace is installed without a cooling coil, a remov-
able access panel must be installed in the supply air duct.
The access panel should be large enough to permit in-
spection (either by smoke or reected light) of the heat
exchanger for leaks after the furnace is installed. The
furnace access panel must always be in place when the
furnace is operating and it must not allow leaks into the
supply air duct system.
To Next Page
Loading...
Need help?
General