507582-04
Page 28 of 54
Issue 2220
Details of Exhaust Piping Terminations for Non-
Direct Vent Applications
Exhaust pipe may be routed either horizontally through
an outside wall or vertically through the roof. In attic or
closet installations, vertical termination through the roof
is preferred. Figure 39 through Figure 42 show typical
terminations.
1.
Exhaust piping must terminate straight out or up as
shown. The termination pipe must be sized as listed
in Table 9. The specified pipe size ensures proper
velocity required to move the exhaust gases away
from the building.
2.
On field supplied terminations for side wall exit,
exhaust piping may extend a maximum of 12 inches
(305 mm) for 2” PVC and 20” (508 mm) for 3” (76 mm)
PVC beyond the outside wall. See Figure 40.
3.
If exhaust piping must be run up a sidewall to position
above snow accumulation or other obstructions, piping
must be supported every 24” (610 mm) as shown in
Figure 41. When exhaust piping must be run up an
outside wall, any reduction in exhaust pipe size must
be done after the final elbow.
Figure 39.
Non-Direct Vent Roof Termination Kit
Figure 40.
Non-Direct Vent Field Supplied Wall
Termination
Figure 41.
Non-Direct Vent Field Supplied Wall
Termination Extended
Figure 42.
Non-Direct Vent Application Using Existing
Chimney
Exhaust through Crawl Space Vent Option
All 33” condensing gas furnaces (92%+) are now approved
to be vented down through a crawl space. Ensure a vent
pipe drain kit, 51W18 (USA) or 15Z70 (Canada), is used as
directed through the floor joists and into the crawl space.
See the following figures.
Consult the vent tables for vent lengths and approved
materials.
