International comfort products F8MVL Installation Instructions Manual page 26

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 211−2012 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 Z223.1−2012 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 Z223.1−2012 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 max-
imum capacity given in Table 7, and
4. The input rating of each space heating appliance is greater
than the minimum input rating given in Table 8 for the local
99% Winter Design Temperature. Chimneys having intern-
al areas greater than 38 sq. in. (24516 sq. mm) require fur-
nace input ratings greater than the input ratings of these
furnaces. See footnote at bottom of Table 8, 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 chimney
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 re-
quired by local code, refer to the NFPA 54/ANSI
Z223.1−2012, Section 12.10 for additional informa-
tion 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.
26
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.
VENT HEIGHT
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 60_F db ex-
cept for brief periods of time during warm−up from setback
at no lower than 55_F (13_C) db or during initial start−up
from a standby condition.
2. Adjust the gas input rate per the installation instructions.
Low gas input rate causes low vent gas temperatures,
causing condensation and corrosion in the furnace 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 condens-
ation problems.
4. Set the thermostat heat anticipator or cycle rate to reduce
short cycling.
Specifications are subject to change without notice.
Exterior Masonry Chimney FAN + NAT
Installations with Type−B Double−Wall Vent
Connectors ENFPA & AGA
Table 7 – Combined Appliance Maximum Input
Rating in Thousands of Btuh per Hour
INTERNAL AREA OF CHIMNEY
SQ. IN. (SQ. MM)
FT (M)
12 19
(7741) (12258)
6 (1.8) 74 119
8 (2.4) 80 130
10 (3.0) 84 138
15 (4.5) NR 152
20 (6.0) NR NR
30 (9.1) NR NR
28 38
(18064) (24516)
178 257
193 279
207 299
233 334
250 368
NR 404
441 01 2122 01