508151-01
Issue 2104
Page 42 of 72
Figure 35. Vent Termination Clearances
Non-Direct Vent Installations
VENT TERMINATION CLEARANCES
FOR NON-DIRECT VENT INSTALLATIONS IN THE US AND CANADA
K
D
E
L
B
C
F
G
A
B
J
A
M
I
H
INSIDE CORNER
DETAIL
VENT TERMINAL
AIR SUPPLY INLET
AREA WHERE TERMINAL
IS NOT PERMITTED
Fixed
Closed
Operable
B
Fixed
Closed
Operable
B
B
A =
B =
C =
D =
E =
F =
G =
H =
I =
J =
K =
L =
M =
US Installations
1
Canadian Installations
2
12 inches (305mm) or 12 in. (305mm)
above average snow accumulation.
12 inches (305mm) or 12 in. (305mm)
above average snow accumulation.
Clearance above grade, veranda,
porch, deck or balcony
Clearance to window or
door that may be opened
4 feet (1.2 m) below or to side of opening;
1 foot (30cm) above opening
6 inches (152mm) for appliances <10,000
Btuh (3kw), 12 inches (305mm) for
appliances > 10,000 Btuh (3kw) and
<100,000 Btuh (30kw), 36 inches (.9m)
for appliances > 100,000 Btuh (30kw)
Clearance to permanently
closed window
Vertical clearance to ventilated soffit
located above the terminal within a
horizontal distance of 2 feet (610 mm)
from the center line of the terminal
Clearance to unventilated soffit
Clearance to outside corner
Clearance to inside corner
tended above meter / regulator assembly
Clearance to service regulator
vent outlet
Clearance to non-mechanical air
pliance
ply inlet
Clearance above paved sidewalk or
paved driveway located on public property
Clearance under veranda, porch, deck or balcony
* 12”
* Equal to or greater than soffit depth.
*
* 3 feet (.9m)
* 12”
3 feet (.9m) within a height 15 feet (4.5m)
above the meter / regulator assembly
3 feet (.9m)
6 inches (152mm) for appliances <10,000
Btuh (3kw), 12 inches (305mm) for
appliances > 10,000 Btuh (3kw) and
<100,000 Btuh (30kw), 36 inches (.9m)
for appliances > 100,000 Btuh (30kw)
3 feet (.9m) above if within 10 feet
(3m) horizontally
6 feet (1.8m)
7 feet (2.1m)†
12 inches (305mm)‡
1
In accordance with the current ANSI Z223.1/NFPA 54 Natural Fuel Gas Code
2
In accordance with the current CSA B149.1, Natural Gas and Propane Installation 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. Allied Air recommends
avoiding this location if possible.
4 feet (1.2 m) below or to side of opening;
1 foot (30 cm) above opening
7 feet (2.1m)†
* Equal to or greater than soffit depth.
* Equal to or greater than soffit depth.
* Equal to or greater than soffit depth.
* No minimum to outside corner
* No minimum to outside corner
3 feet (.9m) within a height 15 feet (4.5m)
above the meter / regulator assembly
*12 inches (305mm)‡
*
*
*For clearances not specified in ANSI Z223.1/NFPA 54 or CSA
B149.1, clearance will be in accordance with local installation
codes and the requirements of the
lation instructions.”