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Indoor Coil Placement
When matching a Lennox branded Acoil to an upflow oil
furnace, make sure coil width is appropriate for full air flow
into and through the coil. If there is any doubt, it is recom
mended that coil is installed at least four inches above the
furnace cabinet. If a nonLennox coil is used, consult the
coil’s literature for the recommended distance from the top
of the furnace cabinet. If the literature does not have a re
commended distance, the coil should be mounted at least
eight inches above top of furnace cabinet
.
Venting
WARNING
Combustion air openings in front of the furnace
must be kept free of obstructions. Any obstruction
will cause improper burner operation and may re
sult in a fire hazard.
WARNING
The barometric draft control must be removed from
the vent pipe when using an air intake kit. Deviation
from this practice will cause improper burner opera
tion and may allow flue products into the living
space which may result in personal injury or death.
An air intake kit used to to provide fresh air directly to the
burner, is available through Lennox. Order part number
11F44.
Figure 9
Vacuum
Relief
Valve
Air Intake Kit
Air Intake Kit Installed
CAUTION
Do not store combustible materials near the furnace
or supply air ducts. The material (such as paint, mo
tor oil, gasoline, paint thinner, etc.) may ignite by
spontaneous combustion creating a fire hazard.
WARNING
This furnace is certified for use with type “L” vent.
“B” vent must not be used with oil furnaces.
Prior to installation of unit, make a thorough inspection of the
chimney to determine whether repairs are necessary. Make
sure the chimney is properly constructed and sized ac
cording to the requirements of the National Fire Protection
Association. The smallest dimensions of the chimney
should be at least equal to the diameter of the furnace vent
connector. Make sure the chimney will produce a steady
draft sufficient to remove all the products of combustion
from the furnace. A draft of at least .04” w.c. (9.9 Pa) is re
quired during burner operation.
1 - Local building codes may have more stringent instal
lation requirements and should be consulted before
installation of unit.
2 - The vent connector should be as short as possible to
do the job.
3 - The vent connector should not be smaller than the
outlet diameter of the vent outlet of the furnace.
4 - Pipe should be at least 24 gauge galvanized.
5 - Single wall vent pipe sh+ould not run outside or
through any unconditioned space.
6 - Chimney should extend 3 feet (0.9 m) above highest
point where the vent passes through the roof, and 2
feet (0.6 m) higher than any portion of a building within
a horizontal distance of 10 feet (3 m).
7 - The vent must not pass through a floor or ceiling.
Clearances to single wall vent pipe should be no less
than 6” (152 mm); more if local codes require it.
8 - The vent may pass through a wall where provisions
have been made for a thimble as specified in the Stan
dards of the National Board of Fire Underwriters. See
figure 10.
Wall Thimble
Figure 10
Thimble
Vent Pipe
Combustible
Wall
9 - The vent pipe should slope upward toward the chim
ney on horizontal run at least 1/4 inch (6 mm) to the
foot (0.3 m) and should be supported by something
other than the furnace, such as isolation hangers.
