Installation and Maintenance Manual

Installation: Mechanical
GLND-SVX01B-EN 13
Access panels large enough to observe smoke and
reflected light, and to detect the presence of leaks in the
heating equipment, are required both upstream and
downstream from gas duct furnaces. These panels must
be sealed to prevent air leaks. If allowed by local
regulations, install canvas connectors between the
ductwork and fan discharge opening to eliminate the
transmission of mechanical vibration.
Air Flow
The installation is to be adjusted to obtain an air
throughput within the range specified on the appliance
rating plate.
Combustion Inlet Air Ventilation
Inlet Air From Another Room
If the duct furnace is installed in a tightly constructed room
or compartment, provide two inlet air openings. The size
of each vent opening should be no less than one square
inch (6.452 square centimeters) of free area for each 1000
Btu/hr. (293 W) input. Each opening must not be less than
100 square inches (645 square centimeters).
Inlet Air From Outdoors
If the enclosed space is to have inlet combustion air from
the outside, the vent opening must not be smaller than one
square inch (6.452 square centimeters) of free area for
each 2500–3000 Btu/hr (733–879 W) input. Each opening
must not be less than 100 square inches (645 square
centimeters).
Bypass
When a gas duct furnace is installed to operate in
conjunction with a summer air conditioning system, the
cfm air delivery of the system blower should be adjusted
to meet the design air volume requirements for cooling. If
this cfm delivery is greater than that required for heating,
resulting in a low air temperature rise, install a damper
bypass around the gas duct furnace to bypass a portion of
the air.
Suspension
Figure 8. Recommended ductwork design for elbowed
arrangement
WARNING
Heavy Objects!
Ensure that all hardware used in the suspension of each
duct furnace is capable of supporting the unit weight.
Failure to do so could result in unit falling off its
mounting location, which could result in death or
serious injury.
NOTICE:
Equipment Damage!
The duct furnace must be hung level from side to side
and front to back, from four suspension points provided
at the top of the unit. Failure to do so could result in
poor performance and/or premature failure of the unit.
Refer to Figure 9, p. 14 for typical suspension
arrangements.
WARNING
Heavy Objects!
Make certain that the lifting methods used to lift the
duct furnace and the method of suspension used in the
field installation of the duct furnace are capable of
uniformly supporting the weight of the furnace at all
times. Make certain that the structure to which the
furnace is mounted is capable of supporting its weight.
Under no circumstances must the heater gas lines, the
venting system or the electrical conduit be used for
support. Failure to follow recommendations could
result in death, serious injury, or property damage.