Clearance Requirements from Vent Terminations to Building Openings
* All clearance requirements are in accordance with ANSI Z21.10.3 and the National Fuel Gas Code,
ANSI Z223.1 and in Canada, in accordance with NSCNGPIC.
Clearance
Above grade, veranda, porch, deck,
A=
or balcony
Window or door that may be opened
B=
C=
Permanently closed window
Vertical clearance to ventilated soffit
located above the terminal within a
D=
horizontal distance of 0.6m (2') from
the center of the terminal
Unventilated soffit
E=
Outside corner
F=
Inside corner
G=
Each side of center line extended
H=
above meter/regulator assembly
Service regulator vent outlet
I=
Nonmechanical air supply inlet or
J=
combustion air inlet to any other
appliance
Mechanical air supply inlet
K=
Above paved sidewalk or paved
L=
driveway located on public property
Under veranda, porch, deck, or
M=
balcony
[ ]= indicates clearances required in Canada
* Maintain clearances in accordance with local installation codes and the requirements of the gas supplier
*** A vent shall not terminate directly above a sidewalk or paved driveway that is located between two
single family dwellings and serves both dwellings.
**** Permitted only if veranda,porch,deck,or balcony is fully open on a minimum of two sides beneath the floor.
Vent Terminal
Air Supply Inlet
Indoor Installation
(See p.10)
300mm (12") [300mm (12")]
1.2m (4') below or to the side of
opening, or 0.3m (1') above
opening [900mm (36")]
*
*
*
*
*
0.9m (3') within a height 4.5m (15')
above meter/regulator assembly
0.9m (3')
1.2m (4') below or to the side of
opening, or 0.3m (1') above
opening [900mm (36")]
0.9m (3') above if within
3m (10') [1.8m (6')]
[2.1m *** (7' ***)]
*[300mm (12") - Canada Only****] *[300mm (12") - Canada Only****]
Area Where Terminal
is Not Permitted
Outdoor Installation
(See p.10, 11)
300mm (12") [300mm (12")]
300mm (12") [900mm (36")]
*
*
*
*
*
0.9m (3') within a height 4.5m (15')
above meter/regulator assembly
0.9m (3')
300mm (12") [900mm (36")]
0.9m (3') above if within
3m (10') [1.8m (6')]
[2.1m *** (7' ***)]
9