Installer’s Guide
Table 11
Non-Direct Vent Terminal Clearances
Canadian Installations
US Installations
A=
Clearance above grade, veranda, porch, deck,
or balcony
12 inches (30 cm)
12 inches (30 cm)
B=
Clearance to window or door that may be opened
6 inches (15 cm) for appliances =/< 10,000 Btuh (3 kw),
12 inches (30 cm) for appliances > 10,000 Btuh (3 kw)
and =/< 100,000 Btuh (30 kw),
36 inches (91 cm) for appliances > 100,000 Btuh (30 kw)
4 feet (1.2m) below or to the side of opening; 1 foot
(0.3m) above opening.
C=
Clearance to permanently closed window
*
*
D=
Vertical clearance to ventilated soffit located
above the terminal within a horizontal distance
of 2 feet (61 cm) from the center line of the terminal
*
*
E=
Clearance to unventilated soffit
*
*
F=
Clearance to outside corner
*
*
G=
Clearance to inside corner
*
*
H=
Clearance to each side of center line extended above
meter/regulator assembly
3 feet (91 cm) with a height 15 feet (4.5 m) above
the meter/regulator assembly
*
I=
Clearance to service regulator vent outlet
3 feet (91 cm)
*
J=
Clearance to nonmechanical air supply inlet to building or
the combustion air inlet to any other appliance
6 inches (15 cm) for appliances =/< 10,000 Btuh (3 kw),
12 inches (30 cm) for appliances > 10,000 Btuh (3 kw)
and =/< 100,000 Btuh (30 kw),
36 inches (91 cm) for appliances > 100,000 Btuh (30 kw)
4 feet (1.2 m) below or to side of opening;
1 foot (300 m) above opening
K=
Clearance to a mechanical air supply inlet
6 feet (1.83m)
3 feet (91 cm) above if within
10 feet (3m) horizontally
L=
Clearance above a paved sidewalk or paved driveway
located on public property
7 feet (2.13 m) †
7 feet (2.13 m)
M=
Clearance under veranda, porch, deck, or balcony
12 inches (30 cm) ‡
*
Notes:
1. In accordance with the current CSA B149.1 Natural Gas and Propane Installation Code.
2. In accordance with the current ANSI Z223.1/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 dwelling and serves both dwellings.
‡. Permitted only if veranda, porch, deck, or balcony is fully open on a minimum of two sides beneath the floor.
* Clearance in accordance with local installation codes and the requirements of the gas supplier and the manufacturer's Installation Instructions.
Table 12
Direct Vent Terminal Clearances
Canadian Installations
US Installations
A=
Clearance above grade, veranda, porch, deck,
or balcony
12 inches (30 cm)
12 inches (30 cm)
B=
Clearance to window or door that may be
opened
6 inches (15 cm) for appliances =/< 10,000 Btuh (3 kw),
12 inches (30 cm) for appliances > 10,000 Btuh (3 kw)
and =/< 100,000 Btuh (30 kw),
36 inches (91 cm) for appliances > 100,000 Btuh (30 kw)
6 inches (15 cm) for appliances =/< 10,000 Btuh (3 kw),
9 inches (23 cm) for appliances > 10,000 Btuh (3 kw)
and =/< 50,000 Btuh (15 kw),
12 inches (30 cm) for appliances > 50,000 Btuh (15 kw)
C=
Clearance to permanently closed window
*
*
D=
Vertical clearance to ventilated soffit located
above the terminal within a horizontal distance
of 2 feet (61 cm)
from the center line of the terminal
*
*
E=
Clearance to unventilated soffit
*
*
F=
Clearance to outside corner
*
*
G=
Clearance to inside corner
*
*
H=
Clearance to each side of center line extended
above meter/regulator assembly
3 feet (91 cm) with a height 15 feet (4.5 m) above the meter/
regulator assembly
*
I=
Clearance to service regulator vent outlet
3 feet (91 cm)
*
J=
Clearance to nonmechanical air supply inlet to
building or the combustion
air inlet to any other appliance
6 inches (15 cm) for appliances =/< 10,000 Btuh (3 kw),
12 inches (30 cm) for appliances > 10,000 Btuh (3 kw)
and =/< 100,000 Btuh (30 kw),
36 inches (91 cm) for appliances > 100,000 Btuh (30 kw)
6 inches (15 cm) for appliances =/< 10,000 Btuh (3 kw),
9 inches (23 cm) for appliances > 10,000 Btuh (3 kw)
and =/< 50,000 Btuh (15 kw), 12 inches (30 cm) for appliances >
50,000 Btuh (15 kw)
K=
Clearance to a mechanical
air supply inlet
6 feet (1.83m)
3 feet (91 cm) above if within 10 feet (3m) horizontally
L=
Clearance above a paved sidewalk
or paved driveway located on
public property
7 feet (2.13 m) †
*
M=
Clearance under veranda,
porch, deck, or balcony
12 inches (30 cm) ‡
*
Notes:
1. In accordance with the current CSA B149.1 Natural Gas and Propane Installation Code.
2. In accordance with the current ANSI Z223.1/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 dwelling and serves both dwellings.
‡. Permitted only if veranda, porch, deck, or balcony is fully open on a minimum of two sides beneath the floor.
* Clearance in accordance with local installation codes and the requirements of the gas supplier and the manufacturer's Installation Instructions.
