506305-01
Page 22 of 36
Issue 0938
Outlet Duct
For installations not equipped with a cooling coil, a removable
access panel must be provided in the outlet duct. The
opening should be accessible when the furnace is placed in
service. 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. The recommended
opening size is 6" x 14" for all sizes.
Duct Connection – G1D93BC Counterflow Models
If a unit is installed on a noncombustible floor, it may be installed
directly over the supply duct or plenum. For installations on
combustible flooring, a special base must be ordered and used.
(See the
Accessories
section on page 31 for more
information.) To install using the special base assembly, see
Figure 34 and the following instructions:
1.
Cut a hole in the floor, sized to provide 1" clearance
between all four sides of the duct and the edge of the
flooring. The four angles on the base assembly should
recess into the floor joists and the base should rest on
all four outside flanges.
2.
Construct duct connections with right angle flanges.
Circulating Air Supply
When the furnace is installed so that the supply ducts carry
air circulated by the furnace to areas outside the space
containing the furnace, the return air shall be handled by a
duct or ducts sealed to the furnace casing and terminated
outside the space containing the furnace.
A return air duct system is recommended. If the unit is
installed in a confined space or closet, a return connection
must be run, full size, to a location outside the closet. The
air duct in the closet must be tight to prevent any entrance
of air from the closet into the circulating air.
If there is no complete return air duct system, the return air
connection must be sealed to the furnace casing and run,
full size, to a location outside the utility room or space housing
the furnace to prevent a negative pressure on the venting
system.
3.
Drop the duct connections through the top of the base
assembly with the right angle flanges in good contact
with the glass tape on top of the base assembly.
4.
Carefully position the furnace over the right angle duct
flanges.
Gas Supply and Piping
Refer to the furnace rating plate to make sure the furnace is
equipped to burn the gas supplied (natural or propane).
Any conversion of a natural gas unit to propane gas must
be done by qualified personnel using a conversion kit
available from the manufacturer, following the instructions
in the conversion kit. If done improperly, overfiring of the
burners and improper burner operation can result. This
can create carbon monoxide which could cause
asphyxiation.
WARNING
When an air conditioning unit is used in conjunction with
the furnace, the evaporator coil must be installed in the
discharge (supply) air. Do not install an evaporator coil
in the return air; excessive condensation will occur within
the furnace.
CAUTION
Combustible Floor Installation
(G1D93BC Counterflow Models Only)
Figure 34
1
"
Combustible
Flooring
Woven
Glass Tape
Base
Assembly
Duct
Furnace
