23
Figure 12b. Direct Vent Terminal Clearances
Canadian
Installations1
US
Installations2
Canadian
Installations1
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)
12 inches
(30.5 cm)
I= Clearance to service
regulator vent outlet or
oil tank vent
36 inches
(91 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)
12 inches
(30.5 cm)
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
12 inches
(30.5 cm)*a
12 inches
(30.5 cm)*a
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
12 inches
(30.5 cm)*a
12 inches
(30.5 cm)*a
L= Clearance above paved
sidewalk or paved
driveway located on
public property
7 feet
(2.1 m)†
*b
F= Clearance to outside
corner
*b *b M= Clearance under a
veranda, porch, deck, or
balcony
12 inches (30.5 cm)‡ 12 inches (30.5
cm)‡
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 must 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”.