Haier GE NF96DS Service Manual page 32

Details of Intake and Exhaust Piping Terminations
for Direct Vent Installations
NOTE: In Direct Vent installations, combustion air is taken
from outdoors and flue gases are discharged to outdoors.
NOTE: Flue gas may be slightly acidic and may adversely
affect some building materials. If any vent termination is used
and the flue gases may impinge on the building material,
a corrosion-resistant shield (minimum 24 inches square)
must be used to protect the wall surface. If the optional
tee is used, the protective shield is required. The shield
should be constructed using wood, plastic, sheet metal or
other suitable material. All seams, joints, cracks, etc. in the
affected area should be sealed using an appropriate sealant.
See Figure 40.
Intake and exhaust pipes may be routed either horizontally
through and outside wall or vertically through the roof. In
attic or closet installations, vertical termination through the
roof is preferred. Figure 29 through Figure 36 show typical
terminations.
1. Intake and exhaust terminations are not required to be
in the same pressure zone. You may exit the intake on
one side of the structure and the exhaust on another
side (Figure 30). You may exit the exhaust out the roof
and the intake out the side of the structure (Figure 31).
2. Intake and exhaust pipes should be placed as close
together as possible at termination end (refer to
illustrations). Minimum separation is 3" (76 mm) on roof
terminations and 6" (152 mm) on sidewall terminations.
3. On roof terminations, the intake piping should terminate
straight down using two 90° elbows (see Figure 29).
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 piping. See
Table 13.
Capacity Exhaust Pipe Size
045 & 070
2"(51mm), 21/2"(64mm),
3"(76mm)
90
* -045, -070 and -090 units with the flush mount termination
must use the 1-1/2" accelerator supplied with the kit.
Table 13. Exhaust Pipe Termination Size Reduction
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 40.
Inches (MM)
12" (305MM) ABOVE
Exhaust
Pipe
Figure 30. Exiting Exhaust and Intake Vent
Roof T erminated
Exhaust Pipe
Termination
Pipe Size
1-1/2"(38mm)
2"(51mm)
Figure 31. Exiting Exhaust and Intake Vent
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 40.
Page 32
3" (76MM) MIN.
8" (203MM) MIN
AVERAGE SNOW
ACCUMULATION
3" (76MM) OR
2" (51MM) PVC
PROVIDE SUPPORT
FOR INTAKE AND
EXHAUST LINES
Figure 29. Direct Vent Roof Termination
Furnace
(no common pressure zone)
Furnace
(no common pressure zone)
SIZE PER EXHAUST PIPE
TERMINATION SIZE
REDUCTION TABLE
UNCONDITIONED
ATTIC SPACE
1/2" (13MM) FOAM
INSULATION IN
UNCONDITIONED
SPACE
Inlet Air
Minimum 12 in.
(305MM) above
grade or snow
accumulation
Inlet Air
Minimum 12 in.
(305MM) above
grade or snow
accumulation
31-5000729 Rev. 0