44
HORIZONTAL TO ROOF
HORIZONTAL TO SIDEWALL
VERTICAL TO SIDEWALL
VERTICAL TO ROOF
VENT PIPE
COMBUSTION-AIR PIPE
COMBUSTION-AIR PIPE
VENT PIPE
COMBUSTION-AIR PIPE
VENT PIPE
COMBUSTION-AIR PIPE
VENT PIPE
12
″
MIN
12
″
MIN
12
″
MIN
(3
0
4.8mm)
12
″
MIN
(3
0
4.8mm)
NOTE
: A 12-in. (3
0
4.8mm) minimum offset pipe section is recommended
with short (5 to 8 ft / 1.5 to 2.5M) vent systems. This recommendation
is to reduce excessive condensate droplets.
(305mm)
(305mm)
A96230
Fig. 43 -- Short Vent System
VENT TERMINATION
General
Combustion-air (direct vent/2-pipe system only) and vent pipe
must terminate outside structure, either through sidewall or roof.
For vent termination clearance, refer to Table 8 for Direct
Vent/2-Pipe system and Table 9 for Non-direct Vent/1-Pipe
system. For exterior piping arrangements, refer to Fig. 44
for Direct Vent/2-Pipe system and Fig. 45 for Non-Direct/
1-Pipe system.
Roof termination is preferred since it is less susceptible to
damage or contamination, and it has less visible vent vapors.
Sidewall termination require sealing or shielding of building
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 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
area shown in Fig. 44 or in Fig. 45 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.
353BA
V
