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unconfined. If the space has an 8 foot ceiling, the
floor area of the space must be 750 square feet
(6,000 / 8 = 750). In general, a furnace installed
in an unconfined space will not require outside
air for combustion. However, in “tight” buildings
(with weather stripping and caulk to reduce
infiltration), it may be necessary to provide
outside air to ensure adequate combustion and
venting, even though the furnace is located in
an unconfined space.
Installation In A Confined Space
A confined space is an area with volume less
than 50 cubic feet per 1,000 Btuh of the com-
bined input rates of all appliances drawing
combustion air from that space. Furnace clos-
ets, small equipment rooms and garages are
confined spaces. Furnaces installed in a con-
fined space which supply heated air to areas
outside the space must draw return air from
outside the space and must have the return air
ducts tightly sealed to the furnace.
A confined
space must have two openings into the
space for combustion air. One opening
must be within 12 inches of the ceiling, and
the other must be within 12 inches of the
floor
. The required sizing of these openings is
determined by whether inside or outside air is
used to support combustion, the method by
which the air is brought to the space, and by the
total input rate of all appliances in the space.
Horizontal Furnace Installation
The *TA series furnaces can be installed hori-
zontally in an attic, basement, crawl space or
alcove. It can be suspended from a ceiling in a
basement or utility room in either a right to left
airflow or left to right airflow. (See Figures 7 and
8.)
If the furnace is to be suspended from the
ceiling, it will be necessary to use steel straps
around each end of the furnace. These straps
should be attached to the furnace with sheet
metal screws and to the rafters with bolts. The
furnace could also be suspended by an angle
iron frame bolted to the rafters. (See Figure 7.)
Access for positioning and servicing must be
considered when locating the unit. Refer to
Table 3, Minimum Clearances to Combustible
Material, for clearance specifications.
Keep all insulating materials away from the
louvered door. Insulating materials may be
combustible.
The *TA series furnace may be installed directly
on combustible wood flooring or supports, if
type "B-1" vent pipe is used (See Figure 8). It
is recommended for further reduction of fire
hazard that cement board or sheet metal be
placed between the furnace and the combus-
tible floor and extend 12 inches beyond the front
of the louvered door.
! WARNING:
Furnaces installed with combustion air
drawn from a heated space which in-
cludes exhaust fans, fireplaces, or other
devices that may produce a negative
pressure should be considered con-
fined space installations.
Figure 7. *TA Horizontal Installation
Suspended in Attic or Crawl Space
Figure 8. *TA Horizontal installation on a
Platform
Gas Inlet
Electrical
Supply
Connection
Coil Plenum
Type “B” Vent
Combustible
Platform
Louver Door
Note: Line
Contact is Permissible
Summary of Contents for TA-060C-08A
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