Venting the Boiler 39
Ref
Description
Canadian Non-Direct Vent
Installations
1
US Non-Direct Vent
Installations
2
A
Clearance above grade, veranda, porch, deck, or balcony
12 in (30 cm)
12 in (30 cm)
B
Clearance to window or door that may be opened
36 in (91 cm)
48 in (120 cm) below or to side
of opening; 12 in (30 cm) 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
36 in (91 cm) within a height
15 ft (4.57 m) above the meter/
regulator assembly
*
I
Clearance to service regulator vent outlet
36 in (91 cm)
*
J
Clearance to non-mechanical air supply inlet to building or
the combustion air inlet to any other appliance
36 in (91 cm)
48 in (120 cm) below or to side
of opening; 12 in (30 cm) above
opening
K
Clearance to a mechanical air supply inlet
6 ft (1.83 m)
36 in (91 cm) above if within 10 ft
(3 m) horizontally
L
Clearance above paved sidewalk or paved driveway
located on public property
7 ft (2.13 m)
†
*
M
Clearance under veranda, porch deck, or balcony
12 in (30 cm)
‡
*
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 dwellings 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.
