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EQUIPMENT IN CONFINED SPACE
ALL AIR FROM OUTSIDE
(All Air Through Ventilated Attic)
NOTE-The inlet and outlet air openings shall each have a
free area of at least 645 mm
2 (
one square inch) per 1.17
kW (4,000 Btu) per hour of the total input rating of all
equipment in the enclosure.
CHIMNEY
OR GAS
VENT
WATER
HEATER
OUTLET
AIR
VENTILATION LOUVERS
(Each end of attic)
INLET AIR
(Ends 12 in.
above bottom)
FURNACE
FIGURE 3
EQUIPMENT IN
CONFINED SPACE
ALL AIR FROM
OUTSIDE
OUTLET AIR
INLET AIR
WATER
HEATER
CHIMNEY
OR GAS
VENT
NOTE - Each air duct opening shall have a free area of at least 645
mm
2 (
one square inch) per .59 kW (2,000 Btu) per hour of the total
input rating of all equipment in the enclosure. If the equipment room
is located against an outside wall and the air openings communi
cate directly with the outdoors, each opening shall have a free area
of at least 645 mm
2
(one square inch) per 1.17 kW (4,000 Btu) per
hour of the total input rating of all other equipment in the enclosure.
FURNACE
FIGURE 4
Setting Equipment
WARNING
Do not install the furnace on its front or its back. Do
not connect the return air ducts to the back of the fur
nace. Doing so will adversely affect the operation of
the safety control devices, which could result in per
sonal injury or death.
NOTE -
As an option, rubberlike pads defined as having an
elastic texture resembling rubber in flexibility or toughness,
may be placed under each corner of the furnace as ap
propriate to the application.
The ML180UHT gas furnace can be installed as shipped in
either the upflow position or the horizontal position.
Select a location that allows for the required clearances
that are listed on the unit nameplate. Also consider gas
supply connections, electrical supply, vent connection, and
installation and service clearances [610 mm (24 inches)] at
unit front.
The unit must be level.
NOTE -
Units with 1/2 hp blower motors
(ML180UH110TP36C and ML180UH090TP48B)are
equipped with three flexible legs and one rigid leg. See fig
ure 5. The rigid leg is equipped with a shipping bolt and a
flat white plastic washer (rather than the rubber mounting
grommet used with a flexible mounting leg).
The bolt and
washer must be removed before the furnace is placed
into operation.
After the bolt and washer have been re
moved, the rigid leg will not touch the blower housing.
NOTE -
ML180UH090TP48B, & ML180UH110TP36C
are also equipped with a shipping pad under the blower
housing. Remove the shipping pad prior to operation.
FIGURE 5
RIGID LEG
remove shipping bolt and washer
ML180UH110TP36C and
ML180UH090TP48B with 1/2 HP
BLOWER MOTOR
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.
