Lennox SIGNATURE SL280UHV Installation Instructions Manual page 8

CHIMNEY OR
GAS VENT
FURNACE
VENTILATION
LOUVERS
(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
AIR FLOW
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
(Inlet Air from Crawlspace and Outlet Air to Ventilated Attic)
VENTILATION LOUVERS
(Each end of attic)
AIR FLOW
FIGURE 3
VENTILATION LOUVERS
(Each end of attic)
INLET AIR
(Ends 12 in.
above bottom)
WATER
HEATER
2
) per 4,000
Page 8
EQUIPMENT IN CONFINED SPACE
ALL AIR FROM OUTSIDE
OUTLET
AIR
WATER
HEATER
INLET
AIR
CHIMNEY
OR GAS
VENT
FURNACE
AIR FLOW
NOTE − Each air duct opening shall have a free area of at least
2
one square inch (645 mm ) per 2,000 Btu (.59 kW) 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 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.
FIGURE 5
EQUIPMENT IN
CONFINED SPACE
ALL AIR FROM
OUTSIDE
WATER
HEATER
OUTLET AIR
INLET AIR
2
)