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• For optimal performance, vent the furnace through a
wall that experiences the least exposure to winter winds.
• The vent termination shall be located at least 3 ft.
horizontally from any electric meter, gas meter, regulator
and any relief equipment. These distances apply ONLY
to U.S. installations. In Canada, CSA B149.1, takes
precedence over these instructions.
• Do not install the vent terminal such that exhaust is
directed into window wells, stairwells, under decks
or into alcoves or similar recessed areas, and do not
terminate above any public walkways.
• If venting horizontally, a side wall vent kit is available
according to the pipe diameter size of the installation.
For 2 inch pipe use side wall vent kit #904617, and
for 3 inch pipe use kit #904347. Please follow the
instructions provided with the kit.
• Concentric vent termination kits are available for use
with these furnaces. For 2 Inch pipe use kit #904952
and for 3 inch pipe use kit # 904953. Please follow the
instructions provided with the kit.
• When the vent pipe must exit an exterior wall close to
the grade or expected snow level where it is not possible
to obtain clearances shown in
provided as shown in
Figure
to prevent freezing of this section of pipe. See
(page 14)
for vent freezing protection.
19" Max.
(See Note)
Support
Outside
Wall
NOTE: Vent Configuration to Provide
12" Minimum height above Snow Level.
Figure 9. Alternate Horizontal Vent Installation
Elbows on the combustion air
inlet must be positioned pointing
away from the exhaust vent.
12" Above Maximum
Expected Snow Level
(Both pipes)
Figure 10. Vertical Vent Termination
Figure
7, a riser may be
9. Insulation is required
Table 2
12" Above
Maximum
Expected
Snow Level
1/2"
Armaflex
Insulation or
Equivalent
(if required)
Plumbing Vent Roof Boot
(Both Pipes)
Outdoor Terminations - Vertical Venting
Termination spacing requirements from the roof and from
each other are shown in
penetration must be properly flashed and waterproofed
with a plumbing roof boot or equivalent flashing. Vent
and combustion air piping may be installed in an existing
chimney which is not in use provided that:
• Both the exhaust vent and air intake run the length of
the chimney.
• The top of the chimney is sealed and weatherproofed.
• The termination clearances shown in
maintained.
• No other gas fired or fuel-burning equipment is vented
through the chimney.
Vent Freezing Protection
CAUTION:
When the vent pipe is exposed to temperatures
below freezing (i.e., when it passes through
unheated spaces, chimneys, etc.) the pipe
must be insulated with 1/2 inch thick sponge
rubber insulation, Armaflex-type insulation or
equivalent. Insulating pipe is important to avoid
condensate icing.
•
Table 2 (page 14)
lists the maximum length of flue
pipe that can travel through an unconditioned space or
an exterior space. The total vent length must not exceed
the lengths noted in
Table 1 (page
installations, please refer to the Canadian Installation
Code (CAN/CGA-B149.1 or 2) and/or local codes.
• For extremely cold climates or for conditions of short
furnace cycles (i.e. set back thermostat conditions) the
last 18 inches of vent pipe can be reduced. It is acceptable
to reduce from 3" to 2-1/2", 3" to 2", or 2" to 1-1/2" if
the total vent length is at least 15 feet in length and the
vent length is within the parameters specified in Table 1.
The restriction should be counted as 3 equivalent feet.
Smaller vent pipes are less susceptible to freezing, but
must not be excessively restrictive. The length of the 2
inch pipe must not be longer than 18 inches.
• If furnace is installed horizontally, make sure the drainage
port on the in-line drain assembly is pointed downward
to ensure proper drainage of condensate. See
38 (page
47).
• To prevent debris or creatures from entering the
combustion system, a protective screen may be installed
over the combustion air intake opening. The screens
hole size must be large enough to prevent air restriction.
Figure 10 (page
13). The roof
Figure 10
11). For Canadian
Figure
are
13
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