21
Figure 12a. Vent Terminal Clearances (Other than Direct Vent or “Power Vented” Installations)
Canadian
Installations
1
US
Installations
2
Canadian
Installations
1
US Installations
2
A= Clearance
above
grade, veranda, porch,
deck or balcony
12 inches
(30.5 cm)
12 inches
(30.5 cm)
H=
Clearance to each side
of center line extended
above meter/regulator
assembly
3 feet
(.9 m)
within a
height 15 feet
(4.6 m)
above the
meter/regulator
assembly
*b
B=
Clearance to widow or
door that may be
opened
36 inches
(91.4 cm)
4 feet
(1.2 m)
below or to the
side of opening;
12 inches
(30.5 cm)
above opening
I=
Clearance to service
regulator vent outlet or
oil tank vent
36 inches
(91.4 cm)
*b
C= Clearance
to
permanently closed
window
*b
*b
J=
Clearance to non-
mechanical air supply
inlet to building or the
combustion air inlet to
any other appliance
36 inches
(91.4 cm)
4 feet
(1.2 m)
below or to side
of opening; 12
inches
(30.5 cm)
above opening.
D=
Vertical clearance to
ventilated soffit
located above the
terminal within a
horizontal distance of
2 feet
(.61 m)
from the
center line of the
terminal
*b
*b
K=
Clearance to a
mechanical air supply
inlet
6 feet
(1.8 m)
3 feet
(.9 m)
above if within
10 feet
(3 m)
horizontally
E= Clearance
to
unventilated soffit
*b
*b
L=
Clearance above paved
sidewalk or paved
driveway located on
public property
7 feet
(2.1 m)
†
7 feet
(2.1 m)
†
F=
Clearance to outside
corner
*b *b
M=
Clearance
under
a
veranda, porch, deck, or
balcony
12 inches
(30.5 cm)
‡ *b
G=
Clearance to inside
corner
36 inches
(91.4 cm)
*a
36 inches
(91.4 cm)
*a
1
In accordance with the current CAN/CGA-B149
Installation Codes
.
2
In accordance with the current ANSI Z223.1-(Latest Edition)/NFPA 54
National Fuel Gas Code
.
† 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 a veranda, porch, deck or balcony is fully open on a minimum of two sides beneath the floor.
*a) A minimum clearance value determined by testing in accordance with section 2.20.
*b) “Clearance in accordance with local installation codes and the requirements of the gas supplier”.
