Rinnai RUC80i Installation And Operation Manual page 32

Certified PVC/CPVC Vent Termination Options (continued)
All figures shown in this section is in reference to flat roofs.
For heights of venting passing through a pitched roof, refer
to NFPA 54/ANSI Z223.1-09 (table and figure 12.7.2), CSA
B149.1-10 (figure 8.1) Pitched Roof Termination Clearances
Diagram (this manual)
PVC/CPVC Roof (Tee and upside down "U") Terminations:
Locate the vent and intake air termination using the
following guidelines:
1. The total length of the vent or intake air piping must
not exceed the limits given in maximum equivalent
vent length tables. The equivalent length for 90° el-
bows and termination associated with the respective
vent and intake air piping arrangement MUST be
subtracted from total length listed in maximum
equivalent vent length tables.
2. For roof terminations installed as shown in figure to the
right, the intake air piping must terminate using a tee
or combination of elbows. The termination must be
installed 12" (30.5 cm) above roof or the highest
anticipated snow level.
3. The vent must terminate vertically with a coupling to
facilitate the bird screen and must be located 12" (30.5
cm) minimum above the combustion air inlet.
4. The vent and intake air terminations must be
located a radial distance of 12" minimum (30.5 cm)
from outer wall of vent termination to outer wall of
combustion air intake termination.
12" min
above air
intake
opening
Vertical Termination of Tee-Vent and Combustion
32
NOTE
Combustion Air Termination
Exhaust Vent Termination
12" min
Air Pipe
12" min
above air
intake
opening
Vertical Termination of U-Vent and Combustion
Multiple Water Heater Installation – Through the Roof
Locate the vent and intake air termination using the
following guidelines:
1. For installations with multiple Tankless Water Heaters,
refer to Figure 16 for proper exhaust and combustion
air piping placement.
2. Roof penetration of the vent and intake air piping
should be such that the combustion air intake is a
minimum 12" (30.5 cm) from the adjacent vent pipe of
the other water heater. For installations in the U.S.
refer to Figure 16. For installations in Canada, refer to
clearances required by CAN/CSA B149.1.
12" above
12" min
grade or
above air
anticipated
intake
snow level
opening
Vertical Termination of Multiple Water Heaters
KBD Series Manual
Vent Termination
Combustion air termination
12" min
Air Pipe
12" min
Vent Termination
Combustion air termination
12" min
12" above
grade or
anticipated
snow level
12" above
grade or
anticipated
snow level