9
D
V
V
E
FIXED
CLOS
ED
OPE
RAB
LE
OPE
RAB
LE
FIXE
D
CLOS
ED
v
v
B
L
F
C
B
v
v
v
X
B
B
B
A
J
B
I
H
X
v
M
K
v
G
A
V VENT TERMINAL
X AIR SUPPLY INLET
AREA WHERE TERMINAL IS NOT PERMITTED
Horizontal Vent Terminal Location
The following information should be used for determining the proper location of the vent terminal
for indoor and outdoor tankless water heaters.
H = Clearance to each side of center line
extended meter/regulator assembly.
above
3 feet (91 cm) within a height 15 feet
(4.57 m) above the meter/regulator
assembly.
*
I = Clearance to service regulator vent
outlet.
3 feet (91 cm)
*
J = Clearance to nonmechanical air
supply inlet to
the
combustion
air inlet to any
building or other
appliance.
6 inches (15 cm) for appliances <
10,000 Btuh (3 kW), 12 inches (30 cm)
for appliances > 10,000 Btuh (3kW)
and < 100,000 Btuh (30kW), 36 inches
(91 cm) for appliances > 100,000 Btuh
(30kW).
6 inches (15 cm) for appliances < 10,000
Btuh (3 kW), 9 inches (23 cm) for
appliances > 10,000 Btuh (3kW) and <
50,000 Btuh (15kW), 12 inches (30 cm)
for appliances > 50,000 Btuh (15kW).
K = Clearance to mechanical
air supply
inlet.
6 feet (1.83 m)
3 feet (91 cm) above if within 10 feet
(3 m)
horizontally.
Canadian Installations
1
Outdoor
US Installations
2
Outdoor
A= Clearance above grade, veranda,
porch, deck or balcony.
12 inches (30 cm) above anticipated
snow level.
12 inches (30 cm) above anticipated
snow level.
B= Clearance to window or door that
may be opened.
6 inches (15 cm) for appliances < 10,000
Btuh (3 kW), 12 inches (30 cm) for
appliances > 10,000 Btuh (3kW) and <
100,000 Btuh (30kW), 36 inches (91 cm)
for appliances > 100,000 Btuh (30kW).
6 inches (15 cm) for appliances <
10,000 Btuh (3 kW), 9 inches (23 cm)
for appliances > 10,000 Btuh (3kW)
and < 50,000 Btuh (15kW), 12 inches
(30 cm) for appliances > 50,000 Btuh
(15kW).
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 corner.
*
*
L = Clearance above paved sidewalk or
paved driveway
located
on public
property.
7 feet (2.13m) †
*
M = Clearance under veranda, porch,
deck or balcony.
Not Allowed
Not Allowed
1
In accordance with current CSA-B149.1 Installation Codes.
2
In accordance with 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.
*
For clearances not specified in ANSI 223.1/NFPA 54 or CSA-B149.12, one of the following shall be indicated:
a)
A minmum clearance value determined by testing in accordance with section 2.20, or;
b)
A reference to the following footnote: "Clearance in accordance with local installtion codes and the require-
ments of the gas supplier."
