507324-01B
Page 14 of 32
Issue 1809
Figure 24. Common Venting Using Tile Lined Interior Masonry Chimney and Combined Vent Connector
NOTE:
Refer to provided
venting tables for
installations.
NOTE:
The chimney must be properly
sized per provided venting tables or lined
with listed metal lining system.
Venting Using a Masonry Chimney
The following additional requirements apply when a lined
masonry chimney is used to vent this furnace.
Masonry chimneys used to vent Category I central furnaces
must be either tile lined or lined with a listed metal lining
system or dedicated gas vent. Unlined masonry chimneys
are prohibited. See Figure 23 and Figure 24 for common
venting.
A chimney with one or more sides exposed to the outside
of the structure is considered to be an exterior chimney.
An exterior masonry chimney that is not tile lined must be
lined with B1 vent or a listed insulated flexible metal vent.
An exterior tile lined chimney that is sealed and capped
may be lined with a listed uninsulated flexible metal vent.
If the existing chimney will not accommodate a listed metal
liner, either the chimney must be rebuilt to accommodate
one of these liners or an alternate approved venting
method must be found.
Insulation for the flexible vent pipe must be an encapsulated
fiberglass sleeve recommended by the flexible vent pipe
manufacturer.
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.
IMPORTANT
Figure 23.
Common Venting Using Metal-Lined
Masonry Chimney
NOTE 1: Refer to the provided venting tables for installations.
Refer to the capacity requirements shown in the provided
venting tables.
DO NOT
insulate the space between the liner and the
chimney wall with puffed mica or any other loose granular
insulating material.
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 drafthood
equipped appliance.
•
The vent connectors and chimney are sized according
to the provided venting tables.
