Rinnai RH180 Operation And Installation Manual page 18

Venting Requirements
Inspection: The entire length of the vent connector shall be readily accessible for inspection, cleaning and
replacement.
Joints: Must be fastened by sheet metal screws or other approved methods.
Support: Vent connectors must be supported per the vent manufacturer's installation instructions to avoid
dips or sags in the vent and maintain the required clearances.
Vent Termination
All flue (Vent) gases must be directed to the outdoors of the building or structure and must not terminate
horizontally.
Table 1
Roof Slope
Flat to 6/12
Over 6/12 to 7/12
Over 7/12 to 8/12
Over 8/12 to 9/12
Over 9/12 to 10/12
Over 10/12 to 11/12
Over 11/12 to 12/12
Over 12/12 to 14/12
Over 14/12 to 16/12
Over 16/12 to 18/12
Over 18/12 to 20/12
Over 20/12 to 21/12
The vent termination shall comply with the following requirements:
If the gas vent is 12 inches (300mm) or less in diameter and located not less than 8 ft (2.4m) from a vertical
wall or similar obstruction, the termination must comply with the requirements stated in Table 1 and Figure
2. If the gas vent is greater than 12 inches in diameter or located less than 8 ft (2.4m) from a vertical wall or
similar obstruction, the termination must end not less than 2 ft (0.6m) above any portion of a building within
10ft (3.0m) horizontally.
B-Vent type gas vent shall terminate at least 5 ft (1.5m) in vertical height above the highest connected
appliance draft hood or flue collar.
Decorative shrouds or coverings shall not be installed over the gas vent termination unless listed for use with
the specific gas vent and are installed in accordance with the manufacturer's installation instructions.
All gas vents shall extend through the roof flashing, roof jack, or roof thimble and terminate with a listed cap
or listed roof assembly.
The gas vent shall terminate at least 3 ft (0.9m) above any forced air inlet located within 10 ft (3.0m)
18
Figure 2
H (minimum)
ft m
1.0 0.30
1.25 0.38
1.5 0.46
2.0 0.61
2.5 0.76
3.25 0.99
4.0 1.22
5.0 1.52
6.0 1.83
7.0 2.13
7.5 2.27
8.0 2.44
RH180 Manual
Lowest discharge opening
Listed
Listed
x
12
Roof pitch is x/12
H (minimum) –
Minimum height from