-- 45 --
surfaces with a corrosive resistance material due to corrosive
combustion products of vent system.
NOTE
: (Direct Vent/2-Pipe system ONLY) A factory accessory
termination kit MUST be used. See section “Vent Termination Kit
(Direct Vent/2-Pipe System Only)” in this instruction.
When determining appropriate location for termination, consider
the following guidelines:
1. Comply with all clearance requirements stated in Table 8
or Table 9 per application.
2. Termination or termination kit should be positioned where
vent vapors will not damage plants/shrubs or air
conditioning equipment.
3. Termination or termination kit should be positioned so that
it will not be affected by wind eddy, such as inside
building corners, nor by recirculation of flue gases,
airborne leaves, or light snow.
4. Termination or termination kit should be positioned where
it will not be damaged by or subjected to foreign objects
such as stones, balls, etc.
5. Termination or termination kit should be positioned where
vent vapors are not objectionable.
Extended Exposed Sidewall Pipes
Sidewall combustion air pipe termination (direct vent/2-pipe
system only) and vent pipe termination may be extended beyond
EXAMPLE:
An 080-12 size furnace located in Indianapolis, elevation
650 ft (198 M) above sea level, could be installed as
either a direct vent/2-pipe system that requires 3 elbows
and 32 ft (9.7 M) of vent pipe, along with 5 elbows and
34 ft (10.3 M) of combustion-air pipe OR a non-direct
vent/1-pipe system that requires 3 elbows and 32 ft (9.7
M) vent pipe.
For a direct vent/2-pipe system, Table 11 indicates this
application would allow a 2--in. (51 mm) diameter vent
pipe, but require a 2-1/2 in. (64 mm) diameter
combustion air pipe. According to Table 11, 2--in. (51
mm) diameter pipe is good for 35 ft ( with 3 elbows, but
only 30 ft (9.1 M) with 5 elbows. Therefore, 2-1/2 in. (64
mm) diameter pipe must be used for both vent and
combustion-air pipes since larger required diameter must
always be used for both pipes.
For a non-direct vent/1-pipe system, Table 11 indicates
that this application would allow a 2--in. (51 mm)
diameter vent pipe. If same installations were in
Albuquerque, elevation 5250 ft (1600 M)above sea level:
For a direct vent/2-pipe system, Table 11 indicates that
2-1/2 in. (64 mm) diameter vent pipe and combustion-air
pipe are required.
For a non-direct vent/1-pipe system, Table 1 indicates
that 2-1/2-in. (64 mm) diameter vent pipe is required.
If same applications are to be installed at 5001-to 6000 ft
(1524.3 to 1828.8 M) elevation:
For a direct vent/2-pipe system, 2--in. (51 mm) pipe is
only good for 23 ft (7.0 M) (with 3 elbows) and 17 ft (5.2
M) (with 5 elbows). Therefore, 2-1/2 in. (64 mm)
diameter combustion air and vent pipe must be used.
For a non-direct vent/1-pipe system, a 2--in. (51 mm)
diameter pipe is only good for 23 ft (7.0 M)with 3
elbows. A 2-1/2-in. (64 mm) diameter vent pipe must be
used.
area shown in Fig. 42 or in Fig. 43 per application in outside
ambient by insulating pipe as indicated in Table 10.
1. Determine
combustion
air
pipe
diameter
(direct
vent/2-pipe system only) and vent pipe diameter, as stated
above, using total pipe length and number of elbows.
2. Using winter design temperature (used in load
calculations), find appropriate temperature for your
application and furnace model.
3. Determine required insulation thickness for exposed
pipe length(s).
NOTE
: Pipe length (ft / M) specified for maximum pipe lengths
located in unconditioned spaces cannot exceed total allowable
pipe length as specified in Table 11.
Vent Termination Kit (Direct Vent/2-Pipe System Only)
NOTE
: Always refer to the instructions in termination kit for the
latest version.
Combustion air and vent pipes MUST terminate outside structure.
A factory accessory termination kit must be installed as shown in
Table 12. There are four options of vent/combustion air
termination kits available as shown in Table 12.
NOTE
: Combustion air pipe must have the same diameter as
vent pipe.
Concentric Vent/Combustion Air Termination Kit (Direct
Vent/2-Pipe System Only)
Determine an appropriate location for termination kit using the
guidelines provided in section “Vent Termination:General” in this
instruction.
1. Cut one 4-in. (102 mm) diameter hole for 2--in. (51 mm)
kit, or one 5-in. (127 mm) diameter hole for 3-in. (76 mm)
kit.
2. Loosely
assemble
concentric
vent/combustion
air
termination components together using instructions in kit.
3. Slide assembled kit with rain shield REMOVED
through hole.
NOTE
: Do not allow insulation or other materials to accumulate
inside of pipe assembly when installing it through hole.
Roof terminations
— Locate assembly through roof to
appropriate height as shown in Fig. 42.
Sidewall terminations
— Locate assembly through sidewall with
rain shield positioned no more than 1-in. (25 mm) from wall as
shown in Fig. 42.
4. Disassemble loose pipe fittings. Clean and cement using
same procedures as used for system piping.
5. Check required dimensions as shown in Fig. 42.
Two-Pipe Termination Kit (Direct Vent/2-Pipe System Only
Determine an appropriate location for termination kit using the
guidelines provided in section “Vent Termination: General” in
this instruction.
1. Cut 2 holes, 1 for each pipe, of appropriate size for pipe
size being used.
2. Loosely install elbow in bracket and place assembly on
combustion-air pipe.
Roof terminations
—Loosely install pipe coupling on
properly cut vent pipe. Coupling must be positioned so
bracket will mount as shown in Fig. 42.
For applications using combustion-air pipe option,
indicated by dashed lines in Fig. 42, install 90
°
street
elbow into 90
°
elbow, making a U-fitting. A 180
°
U-fitting
may be used.
