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FIGURE 12
Front
Back
Horizontal
Downflow Application
Allow for clearances to combustible materials as indicated
on the unit nameplate. Minimum clearances for closet or al
cove installations are shown in figure 13.
Downflow Application Installation Clearances
Top
Bottom
Left Side
Right Side
Type of Vent
Connector
Type C
Type B1
Top
1 in. (25 mm)
1 in. (25 mm)
*Front
2-1/4 in. (57 mm)**
2-1/4 in. (57 mm)
Back
0
0
Sides
0
†
0
Vent
6 in. (152 mm)
1 in. (25 mm)
Floor
NC††
NC††
*Front clearance in alcove installation must be 24 in. (610 mm).
Maintain a minimum of 24 in. (610 mm) for front service access.
** 4-1/2 in. if a single wall vent pipe is used.
†Left side requires 3 in. if a single wall vent is used on 14 -1/2 in. cab
inets, or 2 in. if a single wall vent is used on 17 - 1/2 in. cabinets.
††The furnace may be installed on a combustible wood floor if an
optional additive base is installed between the furnace and the
combustible floor.
FIGURE 13
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 in
let 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.
WARNING
Improper installation of the furnace can result in per
sonal 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 ple
num. 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. Al
low 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 proper
ty damage could result.