FOR NON-DIRECT VENT INSTALLATIONS IN THE US AND CANADA
D
E
B
L
A =
Clearance above grade, veranda,
porch, deck or balcony
B =
Clearance to window or
door that may be opened
C =
Clearance to permanently
closed window
D =
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
E =
Clearance to unventilated soffit
F =
Clearance to outside corner
G =
Clearance to inside corner
H =
Clearance to each side of center line ex
tended above meter / regulator assembly
I =
Clearance to service regulator
vent outlet
J =
Clearance to non-mechanical air
supply inlet to building or the com
bustion air inlet to any other ap
K =
Clearance to mechanical air sup
ply inlet
L =
Clearance above paved sidewalk or
paved driveway located on public property
M =
Clearance under veranda, porch, deck or balcony
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. Lennox recommends
avoiding this location if possible.
507404-04
VENT TERMINATION CLEARANCES
C
Fixed
Closed
F
Operable
B
VENT TERMINAL
4 feet (1.2 m) below or to side of opening;
*
4 feet (1.2 m) below or to side of opening;
pliance
INSIDE CORNER
DETAIL
G
A
B
Operable
B
A
AIR SUPPLY INLET
1
US Installations
12 inches (305mm) or 12 in. (305mm)
above average snow accumulation.
1 foot (30cm) above opening
* 12"
* Equal to or greater than soffit depth.
* Equal to or greater than soffit depth.
* No minimum to outside corner
*
3 feet (.9m) within a height 15 feet (4.5m)
above the meter / regulator assembly
* 3 feet (.9m)
1 foot (30 cm) above opening
3 feet (.9m) above if within 10 feet
(3m) horizontally
7 feet (2.1m)†
*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 gas supplier and these instal
lation instructions."
FIGURE 31
Figure 31
Page 26
Issue 1621
H
B
I
Fixed
Closed
J
AREA WHERE TERMINAL
IS NOT PERMITTED
Canadian Installations
12 inches (305mm) or 12 in. (305mm)
above average snow accumulation.
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)
* Equal to or greater than soffit depth.
* Equal to or greater than soffit depth.
* No minimum to outside corner
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)
6 feet (1.8m)
7 feet (2.1m)†
12 inches (305mm)‡
M
K
2
* 12"
*
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