Canadian Installations
US Installations
A = Clearance above grade, veranda,
12 in (30 cm)
12 in ( 30cm )
porch, deck, or balcony
B = Clearance to window or door that
6 in (15 cm) for appliances 10,000
6 in (15 cm) for appliances 10,000
may be opened
Btuh (3 kW),12 in (30 cm) for
Btuh (3 kW), 9 in (23 cm) for
appliances > 10,000 Btuh (3 kW) and
appliances > 10,000 Btuh (3 kW)
100,000 Btu (30 kW), 36 in (91 cm)
and 50,000 Btuh (15 kW), 12 in (30 cm)
for appliances > 100,000 Btuh (30 kW)
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 ft(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
3 ft (91cm ) within a height 15 ft
*
line extended above
(457 cm) above the meter / regulator
meter/regulator assembly
assembly
I
= Clearance to service regulator
3 ft (91 cm)
vent outlet
J
= Clearance to nonmechanical air
6 in (15 cm) for appliances 10,000 Btuh
6 in (15 cm) for appliances 10,000 Btuh
supply inlet to building or the
(3 kW),12 in (30 cm) for appliances >
(3 kW), 9 in (23 cm) for appliances >
combustion air inlet to any other
10,000 Btuh (3 kW) and 100,000 Btuh
10,000 Btuh (3 kW) and 50,000 Btuh
appliance
(30 kW), 36 in (91 cm) for appliances
(15 kW), 12 in (30 cm) for appliances
> 100,000 Btuh (30 kW)
> 50,000 Btuh (15 kW)
K = Clearance to a mechanical air supply
6 ft (183 cm)
3 ft (91 cm) above if within 10 ft
inlet
(305 cm) horizontally
L
= Clearance above paved sidewalk or
7 ft (213 cm) **
*
paved driveway located on public
property
M = Clearance under veranda, porch
12 in (30 cm) ***
*
deck or balcony
*
**
For clearances not specified in ANSI Z223.1/NFPA 54 or CSA B1 49.1, the following statement shall be included:
"
Clearance in accordance with local installation codes and the requirements of the gas supplier and the manufacturer's
installation instructions."
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 veranda, porch ,deck, or balcony is fully ope n on a minimum of two sides beneath the floor.
23
Direct Vent Terminal Clearances
24
Summary of Contents for operation and
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