Page 10
FIGURE 11
COMMON VENTING USING TILE-LINED INTERIOR MASONRY
CHIMNEY AND COMBINED VENT CONNECTOR
G23
OTHER APPLIANCE
VENT
CONNECTOR
(Double-walled,
single-walled, or in
sulated single-
walled pipe)
MINI. LENGTH = AS SHORT
AS PRACTICAL.
FOR MAX. LENGTH SEE ITEM 4, ON
THE FOLLOWING PAGE.
INTERIOR TILE-
LINED MASONRY
CHIMNEY
NOTE - CHIMNEY MUST BE
PROPERLY SIZED PER THE
PROVIDED VENTING TABLES
OR LINED WITH LISTED METAL
LINING SYSTEM.
NOTE - If vent connector length exceeds 15
ft. (4.5 m), entire length of single-walled
vent connector must be insulated.
PERMANENTLY SEALED
FIREPLACE OPENING
A fan-assisted furnace may be commonly vented into an
existing lined masonry chimney if the following conditions
are met:
1 - The chimney is currently serving at least one draft
hood equipped appliance.
2 - The vent connectors and chimney are sized in accor
dance with the provided venting tables.
IMPORTANT
SINGLE appliance venting of a fanassisted fur
nace into a tilelined masonry chimney (interior or
outside wall) is PROHIBITED. The chimney must
first be lined with either type B1 vent or an insu
lated single wall flexible vent lining system, sized
according to the provided venting tables.
See figures 11 and 12 for common venting.
A type B1 vent or masonry chimney liner shall terminate
above the roof surface with a listed cap or a listed roof as
sembly according to the terms of their respective listings
and the vent manufacturer's instructions.
Do not install a manual damper, barometric draft regula
tor, or flue restrictor between the furnace and the chim
ney.
If type B doublewall vent is used inside a chimney, no oth
er appliance can be vented into the chimney. Outer wall of
type B vent pipe must not be exposed to flue products.
Insulation for the flexible vent pipe must be an encapsu
lated fiberglass sleeve recommended by the flexible vent
pipe manufacturer. See figure 12.
The space between the liner and the chimney wall
should NOT be insulated with puffed mica or any oth
er loose granular insulating material.
FIGURE 12
COMMON VENTING USING
METAL-LINED MASONRY CHIMNEY
4 IN. MIN.
(102mm)
5 FT. (1.5 m)
MINIMUM
MIN. LENGTH -- AS
SHORT AS PRACTICAL
MAX. LENGTH -- SEE
ITEM 10, PAGE 11
SEALED
PERMANENTLY
SEALED FIREPLACE
OPENING
EXTERIOR
CHIMNEY WITH B
VENT OR
INSULATED
FLEXIBLE VENT
PIPE.
