507281-06
Page 27 of 58
Issue 1724
4. Exhaust piping must terminate straight out or up as
shown. A reducer may be required on the exhaust
piping at the point where it exits the structure to
improve the velocity of exhaust away from the intake
Figure 33. Direct Vent Roof Termination Kit
(15F75 or 44J41)
UNCONDITIONED
ATTIC SPACE
3”(76MM) MAX.
12” (305MM) ABOVE
AVERAGE SNOW
ACCUMULATION
3” (76MM) OR
2” (51MM) PVC
PROVIDE SUPPORT
FOR INTAKE AND
EXHAUST LINES
8” (203MM) MIN
Inches(MM)
1/2” (13 mm) FOAM
INSULATION IN
UNCONDITIONED
SPACE
Figure 34. Exiting Exhaust and Intake Vent
(no common pressure zone)
Figure 35. Exiting Exhaust and Intake Vent
(no common pressure zone)
Table 7. Exhaust Pipe Termination Size Reduction
Model
Exhaust Pipe Size
Termination Pipe
Size
045 and 070
2” (51 mm), 2-1/2” (64
mm), or 3” (76 mm)
1-1/2” (38 mm)
090
2” (51 mm)
110
135
3” (76 mm)
Units installed with flush mount termination must use the
1-1/2” accelerator supplied with the kit.
NOTE
:
Care must be taken to avoid recirculation of
exhaust back into intake pipe.
5. On field supplied terminations for sidewall exit, exhaust
piping may extend a maximum of 12 inches (305 mm)
for 2” PVC and 20 inches (508 mm) for 3” (76 mm)
PVC beyond the outside wall. Intake piping should be
as short as possible. See Figure 43.
6. On field supplied terminations, a minimum distance
between the end of the exhaust pipe and the end of
the intake pipe without a termination elbow is 8” and a
minimum distance of 6” with a termination elbow. See
7. If intake and exhaust piping must be run up a side
wall to position above snow accumulation or other
obstructions, piping must be supported every 24”
(610 mm) as shown in Figure 43. Exhaust and
intake piping that is run up a wall is considered to
be in an unconditioned space, so piping should be
sized according to Table 6. The intake piping may be
equipped with a 90° elbow turndown. Using turndown
will add 5 feet (1.5 m) to the equivalent length of the
pipe.
8. A multiple furnace installation may use a group of up to
four terminations assembled together horizontally, as
Figure 36. Direct Vent Concentric Rooftop
Termination
71M80, 69M29 or 60L46 (US)
41W92 or 41W93 (Canada)
