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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
figure 32.
FIGURE 29
UNCONDITIONED
ATTIC SPACE
1/2” (13mm) FOAM
INSULATION IN
UNCONDITIONED
SPACE
SIZE TERMINATION
PIPE PER TABLE 27.
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)
DIRECT VENT ROOF TERMINATION KIT
(15F75 or 44J41)
FIGURE 30
Exhaust
Pipe
Furnace
Exiting Exhaust and Intake Vent
(different pressure zones)
Inlet Air
(Minimum 12 in.
305 MM) above
grade or snow
accumulation
FIGURE 31
Roof Terminated
Exhaust Pipe
Furnace
Exiting Exhaust and Intake Vent
(different pressure zones)
Inlet Air
(Minimum 12 in.
305 MM) above
grade or snow
accumulation
7. If intake and exhaust piping must be run up a side wall
to position above snow accumulation or other ob
structions, piping must be supported. At least one
bracket must be used within 6” from the top of the el
bow and then every 24” (610mm) as shown in figure
32, to prevent any movement in any direction. When
exhaust and intake piping must be run up an outside
wall, the exhaust piping must be terminated with pipe
sized per table 27.The intake piping may be equipped
with a 90° elbow turndown. Using turndown will add 5
feet (1.5m) to the equivalent length of the pipe.
8. Based on the recommendation of the manufacturer, a
multiple-furnace installation may use a group of up to
four terminations assembled together horizontally, as
