39
Venting Information
Table 12. Vent Termination Clearances
CLEARANCE LOCATION
CANADIAN INSTALLATIONS
A
US INSTALLATIONS
B
DIRECT VENT (2-PIPE) &
CONVENTIONAL VENT (1-PIPE)
FURNACES
DIRECT VENT
(2-PIPE) FURNACES
CONVENTIONAL VENT
(1-PIPE) FURNACES
A =
Clearance above grade, veranda, porch, deck,
balcony, or maximum expected snow level.
12 inches (30cm)
12 inches (30cm)
12 inches (30cm)
B =
Clearance to window or door
that may be opened.
6 inches (15cm) for
appliances < 10,000 Btuh (3kW)
6 inches (15cm) for
appliances < 10,000 Btuh (3kW)
4 ft. (1.2m) below or to side
of opening; 1 ft. (300mm)
above opening
12 inches (30cm) for appliances
10,000 Btuh - 100,000 Btuh (30kW)
9 inches (23cm) for appliances
10,000 Btuh - 50,000 Btuh (30kW)
36 inches (91cm) for
appliances > 100,000 Btuh (30Kw)
12 inches (30cm) for
appliances > 50,000 Btuh (30Kw)
C =
Clearance to permanently closed window
*
*
*
D =
Vertical clearance to ventilated soffit located
above the terminal within a horizontal distance
of 2 feet (61cm) 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 (91cm) within a height 15 feet
above the meter/regulator assembly
*
*
I =
Clearance to service regulator vent outlet.
3 feet (1.83m)
*
*
J =
Clearance to non-mechanical air supply inlet to
building or the combustion air inlet to any other
appliance.
6 inches (15cm) for
appliances < 10,000 Btuh (3kW)
6 inches (15cm) for
appliances < 10,000 Btuh (3kW)
4 ft. (1.2m) below or to side
of opening; 1 ft. (300mm)
above opening
12 inches (30cm) for appliances
10,000 Btuh - 100,000 Btuh (30kW)
9 inches (23cm) for appliances
10,000 Btuh - 50,000 Btuh (30kW)
36 inches (91cm) for
appliances > 100,000 Btuh (30Kw)
12 inches (30cm) for
appliances > 50,000 Btuh (30Kw)
K =
Clearance to mechanical air supply inlet.
6 feet (1.83m)
3 feet (91cm) above if within
10 feet (3m) horizontally
3 ft. (91cm) above if within
10 feet (3m) horizontally
L =
Clearance above paved sidewalk or driveway
located on public property.
7 feet (2.13m)
c
*
7 ft. (2.13m)
M =
Clearance under veranda, porch, deck, or
balcony.
12 inches (30cm)
d
*
*
a: In accordance with the current CSA B149.1 Natural Gas and Propane Installation Guide Code
b: In accordance with the current ANSI Z223.1 / NFPA 54 Natural Fuel Gas Code
c: A vent shall not terminate directly above a sidewalk or paved driveway that is located between two single family dwellings and serves both dwellings.
d: Permitted only if veranda, porch, deck, or balcony is fully open on a minimum of two sides beneath the floor.
* For clearances not specified in ANSI Z223.1 / NFPA 54 or CSA B149.1, the following statement shall be included: “Clearance in accordance with local installation
codes, and the requirements of the gas supplier and the manufacturers installation instructions”
VENT TERMINAL
AIR SUPPLY INLET
AREA WHERE TERMINAL IS NOT PERMITTED
