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441 01 2121 01
Masonry Chimney Requirement
NOTE: These furnaces are CSA design−certified for use in
exterior tile−lined masonry chimneys with a factory accessory
Chimney Adapter Kit. Refer to the furnace rating plate for
correct kit usage. The Chimney Adapter Kits are for use with
ONLY furnaces having a Chimney Adapter Kit number
marked on the furnace rating plate.
If a clay tile−lined masonry chimney is being used and it is
exposed to the outdoors below the roof line, relining might be
required. Chimneys shall conform to the Standard for
Chimneys, Fireplaces, Vents, and Solid Fuel Burning
Appliances ANSI/NFPA 211−2009 in the United States and
must be in good condition.
U.S.A.−Refer to Sections 13.1.8 and 13.2.20 of the NFPA
54/ANSI Z223.1−2009 or the authority having jurisdiction to
determine whether relining is required. If relining is required,
use a properly sized listed metal liner, Type−B vent, or a
listed alternative venting design.
NOTE: See the NFPA 54/ANSI Z223.1−2009 13.1.9 and
13.2.20 regarding alternative venting design and the
exception, which cover installations such as our Chimney
Adapter Kits which are listed for use with these furnaces.
The Chimney Adapter Kit is a listed alternative venting
system for these furnaces. See the kit instructions for
complete details.
This furnace is permitted to be vented into a clay tile−lined
masonry chimney that is exposed to the outdoors below the
roof line, provided:
1. Vent connector is Type−B double−wall, and
2. This furnace is common vented with at least 1 draft
hood equipped appliance, and
3. The combined appliance input rating is less than the
maximum capacity given in Table 8, and
4. The input rating of each space heating appliance is
greater than the minimum input rating given in Table 9
for the local 99% Winter Design Temperature. Chim-
neys having internal areas greater than 38 sq. in.
(24516 sq. mm) require furnace input ratings greater
than the input ratings of these furnaces. See footnote
at bottom of Table 9, and
5. The authority having jurisdiction approves.
If all of these conditions cannot be met, an alternative venting
design shall be used, such as the listed chimney adapter kit
with a furnace listed for use with the kit, a listed
chimney−lining system, or a Type−B common vent.
Inspections before the sale and at the time of installation will
determine the acceptability of the chimney or the need for
repair and/or (re)lining. Refer to the Figure 34 to perform a
chimney inspection. If the inspection of a previously used
tile−lined chimney:
a. Shows signs of vent gas condensation, the chim-
ney should be relined in accordance with local
codes and the authority having jurisdiction. The
chimney should be relined with a listed metal liner,
Type−B vent, or a listed chimney adapter kit shall
be used to reduce condensation. If a condensate
drain is required by local code, refer to the NFPA
54/ANSI Z223.1−2009, Section 12.10 for additional
information on condensate drains.
b. Indicates the chimney exceeds the maximum per-
missible size in the tables, the chimney should be
rebuilt or relined to conform to the requirements of
the equipment being installed and the authority hav-
ing jurisdiction.
A chimney without a clay tile liner, which is otherwise in good
condition, shall be rebuilt to conform to ANSI/NFPA 211 or be
lined with a UL listed metal liner or UL listed Type−
B vent.
Relining with a listed metal liner or Type−B vent is considered
to be a vent−in−a−chase.
If a metal liner or Type−B vent is used to line a chimney, no
other appliance shall be vented into the annular space
between the chimney and the metal liner.
Exterior Masonry Chimney FAN + NAT
Installations with Type−B Double−Wall Vent
Connectors ENFPA & AGA
Table 8 – Combined Appliance Maximum Input
Rating in Thousands of Btuh per Hour
VENT HEIGHT
FT (M)
INTERNAL AREA OF CHIMNEY
SQ. IN. (SQ. MM)
12
(7741)
19
(12258)
28
(18064)
38
(24516)
6 (1.8) 74 119 178 257
8 (2.4) 80 130 193 279
10 (3.0) 84 138 207 299
15 (4.5) NR 152 233 334
20 (6.0) NR NR 250 368
30 (9.1) NR NR NR 404
Appliance Application Requirements
Appliance operation has a significant impact on the
performance of the venting system. If the appliances are
sized, installed, adjusted, and operated properly, the venting
system and/or the appliances should not suffer from
condensation and corrosion. The venting system and all
appliances shall be installed in accordance with applicable
listings, standards, and codes.
The furnace should be sized to provide 100 percent of the
design heating load requirement plus any margin that occurs
because of furnace model size capacity increments. Heating
load estimates can be made using approved methods
available from Air Conditioning Contractors of America
(Manual J); American Society of Heating, Refrigerating, and
Air−Conditioning Engineers; or other approved engineering
methods. Excessive oversizing of the furnace could cause
the furnace and/or vent to fail prematurely.
When a metal vent or metal liner is used, the vent must be in
good condition and be installed in accordance with the vent
manufacturer’s instructions.
To prevent condensation in the furnace and vent system, the
following precautions must be observed:
1. The return−air temperature must be at least 60F db
except for brief periods of time during warm−up from
setback at no lower than 55F (13C) db or during ini-
tial start−up from a standby condition.
2. Adjust the gas input rate per the installation instruc-
tions. Low gas input rate causes low vent gas temper-
atures, causing condensation and corrosion in the fur-
nace and/or venting system. Derating is permitted only
for altitudes above 2000 Ft. (610 M).
3. Adjust the air temperature rise to the midpoint of the
rise range or slightly above. Low air temperature rise
can cause low vent gas temperature and potential for
condensation problems.
4. Set the thermostat heat anticipator or cycle rate to re-
duce short cycling.
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