EL280UH Two-Stage Gas Furnace Installation Manual - Lennox

EQUIPMENT IN CONFINED SPACE
ALL AIR FROM OUTSIDE
(Inlet Air from Crawlspace and Outlet Air to Ventilated Attic)
CHIMNEY OR
GAS VENT
VENTILATION LOUVERS
(Each end of attic)
FURNACE
OUTLET
AIR
WATER
HEATER
VENTILATION
LOUVERS
(For unheated crawl space)
INLET
AIR
NOTE−The inlet and outlet air openings shall each have a free area of at least one square inch (645
mm 2 ) per 4,000 Btu (1.17 kW) per hour of the total input rating of all equipment in the enclosure.
FIGURE 4
CHIMNEY
OR GAS
VENT
EQUIPMENT IN CONFINED SPACE
ALL AIR FROM OUTSIDE
(All Air Through Ventilated Attic)
VENTILATION LOUVERS
(Each end of attic)
CHIMNEY
OR GAS
VENT
WATER
HEATER
EQUIPMENT IN
CONFINED SPACE
ALL AIR FROM
OUTSIDE
OUTLET
AIR
OUTLET AIR
FURNACE
INLET AIR
(Ends 12 in.
above bottom)
FURNACE
INLET AIR
WATER
HEATER
NOTE−The inlet and outlet air openings shall each have a
free area of at least one square inch (645 mm 2 ) per 4,000
Btu (1.17 kW) per hour of the total input rating of all equipment
in the enclosure.
FIGURE 5
NOTE − Each air duct opening shall have a free area of at least one
square inch (645 mm 2 ) 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 opening shall have a free area
of at least one square inch (645 mm 2 ) per 4,000 Btu (1.17 kW) per
hour of the total input rating of all other equipment in the enclosure.
FIGURE 6
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