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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 flue 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 fireplace 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 filter or rack. A field-pro
-
vided high-velocity filter is required for the unit to operate
properly. Table 1 lists recommended filter sizes.
A filter must be in place any time the unit is operating.
IMPORTANT
If a highefficiency filter is being installed as part of this
system to ensure better indoor air quality, the filter must
be properly sized. Highefficiency filters have a higher
static pressure drop than standardefficiency glass/foam
filters. 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 filter with this system, check the
specifications provided by the filter manufacturer against
the data given in the appropriate Lennox Product
Specifications bulletin. Additional information is provided
in Service and Application Note ACC002 (August 2000).
TABLE 1
Furnace Cabinet
Width
Filter Size
Side Return
Bottom Return
14-1/2”
16 X 25 X 1 (1)
14 X 25 X 1 (1)
17-1/2”
16 X 25 X 1 (1)
16 X 25 X 1 (1)
21”
16 X 25 X 1 (1)
20 X 25 X 1 (1)
24-1/2”
16 X 25 X 1 (2)
24 X 25 X 1 (1)
