Allied Air Enterprises 92G1UH - Manual (Page 25)

506501-01 Page 25 of 48 Issue 1031
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.
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. Figures 30 through 40 show typical
terminations.
1. Exhaust and intake exits must be in same pressure zone.
Do not exit one through the roof and one on the side.
Also, do not exit the intake on one side and the exhaust
on another side of the house or structure.
2. Intake and exhaust pipes should be placed as close
together as possible at termination end (refer to
illustrations). Maximum 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 30).
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 6.
NOTE: Care must be taken to avoid recirculation of exhaust
back into intake pipe.
EXHAUST PIPE TERMINATION SIZE REDUCTION
Table 6
DIRECT VENT ROOF TERMINATION KIT
(15F75 OR 44J41)
Figure 30
FIELD SUPPLIED WALL TERMINATION
See venting Table 5 for maximum venting lengths with this
arrangement.
* Use wall support every 24” (610 mm). Use two wall supports if
extension is greater than 24” (610 mm) but less than 48” (1219 mm).
NOTE: One wall support must be 6” (152 mm) from top of each pipe
(intake and exhaust).
Figure 31