Lennox ELITE Series Installation Instructions Manual page 16

Common Venting Using Metal-Lined Masonry Chimney
MAX. LENGTH
-- SEE NOTE 1
BELOW.
5 ft. (1.5 m)
MIN. LENGTH -- AS
minimum
SHORT AS PRACTICAL
VENT CONNECTOR
4 in. (102 mm)
minimum
OTHER
APPLIANCE
NOTE 1 - Refer to the provided venting tables for installations. Refer
to the capacity requirements shown in the provided venting tables.
FIGURE 24
DO NOT insulate the space between the liner and
the chimney wall with puffed mica or any other loose
granular insulating material.
IMPORTANT
SINGLE appliance venting of a fan-assisted furnace
into a tile-lined masonry chimney (interior or outside
wall) is PROHIBITED. The chimney must first be
lined with either type B1 vent or an insulated single
wall flexible vent lining system which has been
sized according to the provided venting tables and
the vent pipe manufacturer's instructions.
A fan-assisted furnace may be commonly vented into an
existing lined masonry chimney if the following conditions
are met:
• The chimney is currently serving at least one draft-
hoodequipped appliance;
• The vent connectors and chimney are sized accord-
ing to the provided venting tables.
If type B1 double-wall vent is used inside a chimney, no
other appliance can be vented into the chimney. The outer
wall of type B1 vent pipe must not be exposed to flue prod-
ucts. A type B1 vent or masonry chimney liner shall termi-
nate above the roof surface with a listed cap or a listed
roof assembly according to the terms of their respective
listings and the vent manufacturer's instructions.
SEALED
EXTERIOR
CHIMNEY WITH
METAL
LINER
FURNACE
PERMANENTLY
SEALED FIREPLACE
OPENING
AIR FLOW
When inspection reveals that an existing chimney is not
safe for the intended purpose, it shall be rebuilt to conform
to nationally recognized standards, lined or relined with
suitable materials, or replaced with a gas vent or chimney
suitable for venting EL280UH(X)E series units. The chim-
ney passageway must be checked periodically to ensure
that it is clear and free of obstructions.
Do not install a manual damper, barometric draft regulator,
or flue restrictor between the furnace and the chimney.
Never connect a Category I appliance to a chimney that is
servicing a solid-fuel appliance. If a fireplace chimney flue
is used to vent this appliance, the fireplace opening must
be permanently sealed.
A type B or listed chimney lining system that passes
through an unused masonry chimney flue is not consid-
ered to be exposed to the outdoors.
General Venting Requirements
Vent all EL280UH(X)E furnaces according to these in-
structions:
1 - Vent diameter recommendations and maximum
allowable piping runs are found in the provided
venting tables.
2 - In no case should the vent or vent connector diameter
be less than the diameter specified in the provided
venting tables.
3 - The minimum vent capacity determined by the sizing
tables must be less than the low fire input rating and
the maximum vent capacity must be greater than the
high fire input rating.
4 - Single appliance vents - If the vertical vent or tile-
lined chimney has a larger diameter or flow area than
the vent connector, use the vertical vent diameter to
determine the minimum vent capacity and the vent
connector diameter to determine the maximum vent
capacity. The flow area of the vertical vent, however,
shall not exceed 7 times the flow area of the listed
appliance categorized vent area, drafthood outlet
area or flue collar area unless designed according to
approved engineering methods.
5 - Multiple appliance vents - The flow area of the largest
section of vertical vent or chimney shall not exceed
7 times the smallest listed appliance categorized
vent area, drafthood outlet area or flue collar area
unless designed according to approved engineering
methods.
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