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Venting Information
Table 14
Table 14. 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
Summary of Contents for M4RC-072D-35C
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