22
It is recommended that the outlet duct be pro-
vided with a removable access panel. This
opening should be accessible when the furnace
is installed in service and shall be of a size that
smoke or reflected light may be observed inside
the casing to indicate the presence of leaks in
the heat exchanger. The cover for the opening
shall be attached in such a manner as to prevent
leaks.
If outside air is used as return air to the furnace
for ventilation or to improve indoor air quality, the
system must be designed so that the return air
is not less than 50° F (10° C) during operation.
If a combination of indoor and outdoor air is
used, the ducts and damper system must be
designed so that the return air supply to the
furnace is equal to the return air supply under
normal, indoor return air applications.
When a cooling system is installed which uses
the furnace blower to provide airflow over the
indoor coil, the coil must be installed down-
stream (on the outlet side) of the furnace or in
parallel with the furnace.
If a cooling system is installed in parallel with the
furnace, a damper must be installed to prevent
chilled air from entering the furnace and con-
densing on the heat exchanger. If a manually
operated damper is installed, it must be de-
signed so that operation of the furnace is pre-
vented when the damper is in the cooling posi-
tion and operation of the cooling system is
prevented when the damper is in the heating
position.
Return Air
In applications where the supply ducts carry
heated air to areas outside the space in which
the furnace is installed, the return air must be
delivered to the furnace by duct(s) sealed to the
furnace casing, running full size and without
interruption.
! WARNING:
The solid base of the furnace must be
in place when the furnace is installed
with side return air ducts. Removal of
all or part of the base could cause
products of combustion to be circu-
lated into the living space and create
potentially hazardous conditions, in-
cluding carbon monoxide poisoning
that could result in personal injury or
death.
For Upflow/Horizontal installations:
The
return air ductwork may be connected to any or
all of the following: left side return, right side
return, or bottom return. NOTE: Do not use the
back of the furnace for return air. Table 2, in the
front pages of these instructions, contains the
airflow data for each furnace model. Where
maximum airflow is 1800 CFM or more, two
openings must be used for return air.
Ground Joint
Union
Dripleg
Shut-Off Valve
Burner
Assembly
Manifold
Some utilities
require Shut-Off
Valve to be
4 to 5 feet
above floor
Automatic Gas
Valve (with manual
shut-off)
Upflow Models- Left Side Entry
Figure 24. Typical Gas
Service Connection
Ground Joint
Union
Dripleg
Shut-Off Valve
Manifold
Some utilities
require Shut-Off
Valve to be
4 to 5 feet
above floor
Automatic Gas
Valve (with manual
shut-off)
Burner
Assembly
Downflow Models- Right Side Entry
Summary of Contents for TA-060C-08A
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