Operable
VENT TERMINAL
AIR SUPPLY INLET
AREA WHERE TERMINAL
IS NOT PERMITTED
B
Fixed
Closed
c
B
F
B
L
D
E
J
B
B
B
M
A
Operable
Fixed
Closed
H
Inside Corner
Detail
G
A
Balcony -
with perpendicular side wall
Combustible &
Noncombustible
M = 24” (610 mm)
P = 20” (508 mm)
I
K
Vent Termination Clearances for
Direct Vented Installations in the USA and Canada
The vent for this appliance shall not terminate.
a.
Near the soffit vents or crawl space vents or other areas where condensate or vapor could create a nuisance or hazard
or property damage; or
b.
Where condensate vapor could cause damage or could be detrimental to the operation of regulators, relief valves, or other equipment.
Avoid venting under a deck or large overhang. Recirculation could occur and cause performance or system problems. Ice build-up may occur. Condensation will
accumulate on cold surfaces.
6 inches for appliances < 10,000 Btuh, 12 inches for
appliances > 10,000 Btuh and < 100,000 Btu, 36
inches for appliances > 100,000 Btu
Canadian Installations₂
12 inches or 12 in. above average snow
accumualtion
US Installations₁
* No minimum to outside corner
*
* Equal to or greater than soffit depth
* 12 inches
* Equal to or greater than soffit depth
* 3 feet
6 inches for appliances <10,000 Btuh, 12 inches for
appliances > 10,000 Btuh and < 100,000 Btu, 36
inches for appliances > 100,000 Btu
* 3 feet within a height 15 feet above the meter /
regulator assembly
7 feet †
12 inches (In dead end corners 24")
6 feet
A=
Clearnace above grade, veranda, porch, deck or
balcony
12 inches or 12 in. above average snow
accumualtion
B=
Clearance to window or door that may be opened
4 inches (152mm) for appliances < 10,000 Btuh
(3kw), 9 inches (mm) for appliances > 10,000 Btuh
(3kw) and < 50,000 Btuh (15kw), 12 inches (305mm)
for appliances > 50<000 Btuh (15kw)
C=
Clearance to permanetly closed window
* 12 inches
D=
Vertical clearance to ventilated soffit located above
the terminal within a horizontal distance of 2 feet
from the center line of the terminal
* Equal to or greater than soffit depth
E=
Clearance to unventialted soffit
* Equal to or greater than soffit depth
F=
Clearance to oustside corner
* No minimum to outside corner
G=
Clearance to inside corner
*
H=
Clearnace to each of center line extended above
meter / regulatory assembly
* 3 feet within a height 15 feet above the meter /
regulator assembly
I=
Clearance to service regulator vent outlet
* 3 feet
J=
Clearance to non-mechanical air supply inlet to
building or the combustion air inlet to any other
appliance
4 inches (152mm) for appliances < 10,000 Btuh
(3kw), 9 inches (mm) for appliances > 10,000 Btuh
(3kw) and < 50,000 Btuh (15kw), 12 inches (305mm)
for appliances > 50<000 Btuh (15kw)
* 12 inches ‡
K=
Clearance to mechanical air supply inlet
3 feetabove if within 10 feet (3 m) horizontally
L=
Clearance above paved sidewalk or paved driveway
located on public property.
* 7 feet †
‡. Permitted only if veranda, porch, deck or balcony is fully open on a minimum of two sides beneath the floor.
NCP recommends avoiding this location.
* For clearances not specified in ANSI Z223.1/NFPA
54 or CSA B149.1, clearance will be in accordnace
with local codes and the requirements of the gas
supplier and these installation instructions.
₂
. In accordance with the current CSA B149.1 Natural Gas and Propane Installation Code
₁
In accordance with the current ANSI Z223.1 / NFPA 54 Natural 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.
M=
Clearance under veranda, porch, deck or balcony
Installation/Instruction Manual for Architects & Engineers
15.
