Specifications
18
A venting system that terminates in the sidewall of a structure shall terminate at least 3 ft (0.9 m) above any air inlet to the
structure that is within 10 ft (3 m) of the termination point.
Exception No. 1: This requirement shall not apply to the combustion air intake of a direct vent appliance.
Exception No. 2: This requirement shall not apply to the separation distance between the circulating air inlet and the vent
discharge of a listed outdoor appliance.
The ue gas outlet of an appliance other than a direct vent appliance shall terminate at least 4 ft (1.2 m) below, 4 ft (1.2 m)
horizontally from, or 1 ft (0.3 m) above any door, window, or gravity air inlet of the structure. The outlet also shall terminate
at least 1 ft (0.3 m) above grade.
The combustion air inlet and ue gas outlet of a direct vent appliance or the ue gas outlet of an appliance other than a
direct vent appliance shall terminate at least 1 ft (0.3 m) from the soft of the roof of the structure and at least 3 ft (0.9 m)
from an inside corner of an L-shaped structure.
The ue gas outlet terminal of a direct vent application with an input of 50,000 Btu/hr (0.35 gal/hr) or less shall be located
at least 9 in. (230 mm) from any door, window, or air inlet to the structure. The vent terminal of a direct vent appliance
with an input over 50,000 Btu/hr (0.35 gal/hr) shall be located at least 1 ft (0.3 m) from any door, window, or air inlet to the
structure. Regardless of input, the ue gas outletterminal shall also terminate at least 1 ft (0.3 m) above grade.
The exit terminals of mechanical draft systems shall not be less than 7 ft (2.1 m) above grade when located adjacent to
public walkways.
Any air inlet and any ue gas outlet of any appliance shall terminate at least 5 ft (1.6 m) from the vent outlet of a supply
tank.
Source: NFPA 31: Standard for the Installation of Oil-Burning Equipment