Setting Equipment - Lennox ML180UHA Installation Instructions Manual

EQUIPMENT IN CONFINED SPACE
ALL AIR FROM OUTSIDE
(All Air Through Ventilated Attic)
CHIMNEY
OR GAS
VENT
OUTLET
AIR
FURNACE
NOTE-The inlet and outlet air openings shall each have a
2 (
free area of at least 645 mm
kW (4,000 Btu) per hour of the total input rating of all
equipment in the enclosure.
FIGURE 3
CHIMNEY
OR GAS
VENT
FURNACE
NOTE - Each air duct opening shall have a free area of at least 645
2 (
mm 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
2
of at least 645 mm (one square inch) per 1.17 kW (4,000 Btu) per
hour of the total input rating of all other equipment in the enclosure.
FIGURE 4
VENTILATION LOUVERS
(Each end of attic)
INLET AIR
(Ends 12 in.
above bottom)
WATER
HEATER
one square inch) per 1.17
EQUIPMENT IN
CONFINED SPACE
ALL AIR FROM
OUTSIDE
WATER
HEATER
OUTLET AIR
INLET AIR

Setting Equipment

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 ML180UHA 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
(ML180UH110AP36C and ML180UH090AP48B) are
equipped with three flexible legs and one rigid leg. See
figure 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 removed, the rigid leg will not touch
the blower housing.
NOTE - ML180UH090AP48B, & ML180UH110AP36C
are also equipped with a shipping pad under the blower
housing. Remove the shipping pad prior to operation.
Page 7
WARNING
with 1/2 hp blower
ML180UH110AP36C and
ML180UH090AP48B with 1/2 HP
BLOWER MOTOR
RIGID LEG
remove shipping bolt and washer
FIGURE 5
motors