Lennox SL280V Installation Instructions Manual page 8

CHIMNEY OR
GAS VENT
FURNACE
(For unheated crawl space)
NOTE−The inlet and outlet air openings shall each have a free area of at least one square inch (645
2
mm ) per 4,000 Btu (1.17 kW) per hour of the total input rating of all equipment in the enclosure.
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
free area of at least one square inch (645 mm
Btu (1.17 kW) per hour of the total input rating of all equip-
ment in the enclosure.
FIGURE 4
VENTILATION LOUVERS
(Each end of attic)
VENTILATION
LOUVERS
VENTILATION LOUVERS
(Each end of attic)
INLET AIR
(Ends 12 in.
above bottom)
WATER
HEATER
2
) per 4,000
EQUIPMENT IN CONFINED SPACE
ALL AIR FROM OUTSIDE
(Inlet Air from Crawlspace and Outlet Air to Ventilated Attic)
OUTLET
AIR
WATER
HEATER
INLET
AIR
FIGURE 3
FURNACE
NOTE − Each air duct opening shall have a free area of at least
one square inch (645 mm
the total input rating of all equipment in the enclosure. If the
equipment room is located against an outside wall and the air
openings communicate directly with the outdoors, each open-
ing shall have a free area of at least one square inch (645 mm
per 4,000 Btu (1.17 kW) per hour of the total input rating of all
other equipment in the enclosure.
Page 8
EQUIPMENT IN
CONFINED SPACE
ALL AIR FROM
OUTSIDE
CHIMNEY
OR GAS
VENT
WATER
HEATER
OUTLET AIR
INLET AIR
2
) per 2,000 Btu (.59 kW) per hour of
FIGURE 5
2
)