18
18-CE15D1-1C-EN
General Venting
VENT PIPING
These furnaces have been classified as Fan-Assisted
Combustion System, Category I furnaces under the
"latest edition" provisions of ANSI Z21.47 standards.
Category I furnaces operate with a non-positive vent
static pressure and with a flue loss of not less than 17
percent.
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mp
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ntt:: To reduce the combustion back pressure
tones that may occur, the minimum overall
length of B-vent must be 7 feet.
Multistory and common venting are permitted for
these furnaces. Venting systems shall be in accordance
with the National Fuel Gas Code, ANSI Z223.1/NFPA 54,
local codes, and this installation manual.
Side wall termination with the use of an add-on draft
inducer is not allowed with this furnace.
The furnace shall be connected to a factory built
chimney or vent complying with a recognized standard,
or a masonry or concrete chimney lined with a lining
material acceptable to the authority having jurisdiction.
VENTING INTO A MASONRY CHIMNEY
If the chimney is oversized, the liner is inadequate, or flue-gas
condensation is a problem in your area, consider using the chimney as
a pathway or chase for type "B" vent or flexible vent liner. If flexible
liner material is used, size the vent using the "B" vent tables, then
reduce the maximum capacity by 20% (multiply 0.80 times the
maximum capacity). Masonry Chimney Kit BAYVENT800B may be
used with these furnaces
(Upflow model furnaces only)
to allow
venting into a masonry chimney. Refer to the BAYVENT800B
Installer’s Guide for application requirements.
INTERNAL MASONRY CHIMNEYS
Venting of fan assisted appliances into a lined, internal masonry
chimney is allowed only if it is common vented with at least one
natural draft appliance;
OR
, if the chimney is lined with type "B",
double wall vent or suitable flexible liner material
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The following section does not apply if BAYVENT800B (Masonry Chimney Vent Kit) is used. All instructions with the kit must be
followed.
Masonry Chimney Venting
Type Furnace
Tile Lined Chimney
Chimney Lining
Internal
External
“B” Vent
Flexible Metal Liner
Single Fan Assist
No
No
Yes
Yes
(a)
Fan Fan Assist
No
No
Yes
Yes
Fan Natural
Yes
No
Yes
Yes
(a)
Flexible chimney liner size is determined by using the type "B" vent size for the available BTUH input, then reducing the maximum capacity by 20%
(multiply maximum capacity times 0.80). The minimum capacity is the same as shown in the "B" vent tables.
