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Canada
(and
U.S.A.)-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 dralX hood-
equipped
appliance,
and
3. The combined
appliance
input rating is less than the maximnm
capacity
given
in Table
A, and
4. The input
rating
of each space
beating
appliance
is greater
than the mininmm
input
rating given
in Table
B Xk)rthe local
99(A Winter
Design
Temperature.
Chinmeys
having
internal
areas
greater
than
38 square
inches
require
furnace
input
ratings
greater
than the
input ratings
of these
furnaces.
See
R)otnote
at bottom
of Table
B, 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
chiumey
adapter
kit with
these
X'urnaces,
which
are listed
lor use with
the
kit, a listed
chiumey-lining
system,
or a Type-B
counnon
vent.
Inspections
belore
the
sale and at the time
of installation
will
determine
the acceptability
of the chiumey
or the need Xi_rrepair
and/or
(re)lining.
Rel_:r to the
Fig.
33 to perXkmn
a chiumey
inspection.
If the inspection
of a previously
used tile-lined
chim-
ney:
a. Shows
signs of vent gas condensation,
the chiumey
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 chiumey
adapter
kit shall be used to reduce
condensation.
Xf a condensate
drain is required
by local code, reli:r to the NFGC,
Section
10.9 R)r additional
inR)rmation
on condensate
drains.
b. Indicates
the chimney
exceeds
the maximum
permissible
size in the tables,
the chimney
should
be rebuilt
or relined
to conform
to the requirements
of the equipment
being
installed
and the authority
having jurisdiction.
A chimney
without
a clay tile liner,
which
is otherwise
in good
condition,
shall
be rebuilt
to conXimn
to ANS1/NFPA
211 or be
lined with a UL listed
(ULC
listed in Canada)
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
cbinmey
and the metal
liner.
Exterior
Masonry
Chimney
FAN + NAT
installations with Type-B Double-WaJJ Vent
Connectors
©NFPA
& AGA
Table A--Combined
Appliance
Maximum
input
Rating in Thousands
of BTU per Hour
iNTERNAL
AREA OF CHIMNEY
VENT HEIGHT (FT)
(SQ, IN.)
6
8
10
15
20
30
38
74
119
178
257
80
130
193
279
84
138
207
299
NR
152
233
334
NR
NR
250
368
NR
NR
NR
404
o
,2 °
,€
o
o
T
Table B--Minimum
Alowable input Rating of
Space-Heating
Appliance in
Thousands
of BTU per Hour
i
INTERNAL AREA OF CHIMNEY
VENT
(SQ. IN.)
NaGHT(FT) 12 I
19 I
28 I
a8
Lecal
99%
Winter
Design
Temperature:
17 to 26 degrees
F*
6
0
55
99
141
8
52
74
111
154
10
NR
90
125
169
15
NR
NR
167
212
20
NR
NR
212
258
30
NR
NR
NR
362
Local 99% Winter
Design
Temperature:
5 to 16 degrees
F*
6
NR
78
121
166
8
NR
94
135
182
10
NR
111
149
198
15
NR
NR
193
247
20
NR
NR
NR
293
30
NR
NR
NR
377
Lecal 99% Winter
Design
Temperature:
-10 te 4 degrees
F*
6
NR
NR
145
196
8
NR
NR
159
213
10
NR
NR
175
231
15
NR
NR
NR
283
20
NR
NR
NR
333
30
NR
NR
NR
NR
Local 99% Winter
Design
Temperature:
-11 degrees F or lower*
o
Not recommended
for any vent
configuration
*The 99% Winter
Design Dry-Bulb
(db) temperatures
are found in the 1993
ASHRAE
Fundamentals
Handbook,
Chapter 24, Table 1 (United States) and
2 (Canada),
or use the 99.6% heating db temperatures
found in the 1997 or
2001 ASHRAE
Fundamentals
Handbook,
Climatic
Design Information
chap-
ter, Table 1A (United States) and 2A (Canada).
APPLIANCE APPLXCAT1ON REQUIREMENTS
Appliance operation has a significant impact on the perXormance
of the venting system.
If the appliances
are size& installe&
adjusted, and operated properly, the venting system and/or the
appliances should not sufli:r l?'om condensation and corrosion. The
venting system and all appliances shall be installed in accordance
with applicable listings, standards, and codes.
The lurnace 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 l_'om Air Condi-
tioning Contractors of America (Manual J); American Society of
Heating, Refl'igerating, and Air-Conditioning
Engineers; or other
approved engineering methods. Excessive oversizing of the fur-
nace could cause the li_rllace and/or vent to fail prematurely.
When a metal vent or metal liner is used, the yen{ must be in good
condition and be installed in accordance with the vent manulk_c-
turer's instructions.
27
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