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FIGURE 2. VENT TERMINAL CLEARANCES

V VENT TERMINAL

X AIR SUPPLY INLET

AREA WHERE TERMINAL

IS NOT PERMITTED

Ca nadian Installations ¹

U.S. Installations ²
A = Clearance above grade, veranda , porch, deck, or balcony 12 Inches (30 cm) 12 Inches (30 cm)
B = Clearance to window or door tha t may be opened 6 Inches (15 cm) for appliances < 10 ,000 Btuh (3 kw), 12 inches (30 cm )
for appliances > 10,000 Btuh (3 kw) and < 100,000 Btuh (30 kw), 36
inches (91 cm) for appliances > 100,0 00 Btuh (30 kw)
6 Inches (15 cm) for appliances < 10 ,000 Btuh (
3
for appliances > 10,000 Btuh (3 kw) an d < 50,0
0
inches (30 cm) for appliances > 50,00 0 Btuh (15
C = Clearance to permanently closed window *12 Inches (30 cm) recommended to p revent condensation on window *12 Inches (30 cm) rec ommended to prevent co
n
D = Vertical clearance to ventilated soffit located
above the terminal within a horizon tal distance of
2 feet (61 cm) from the center line of the terminal
*18 Inches (46 cm)
*18 Inches (46 cm)
E = Clearance to unventilated soffit *12 Inches (30 cm) *12 Inches (30 cm)
F = Clearance to outside corner *12 Inches (30 cm) *12 Inches (30 cm)
G = Clearance to inside corner *24 Inches (60 cm) *24 Inches (60 cm)
H = Clearance to each side of cent er line extended
above meter/regulator assembly
3 feet (91 cm) within a height 15 feet (4.5 m) above the meter/regulator
assembly
Clearance in accordance with local inst allation c
o
requirements of the gas supplier.
I = Clearance to service regulator ven t outlet 3 feet (91 cm) Clearance in accordance with local insta llation c
o
requirements of the gas supplier.
J = Clearance to nonmechanical ai r supply inlet to
building or the combustion air in let to any other
appliance
6 Inches (15 cm) for appliances < 10 ,000 Btuh (3 kw), 12 inches (30 cm )
for appliances > 10,000 Btuh (3 kw) and < 100,000 Btuh (30 kw), 36
inches 91 cm) for appliances > 100,0 00 Btuh (30 kw)
6 Inches (15 cm) for appliances < 10 ,000 Btuh (
3
for appliances > 10,000 Btuh (3 kw) an d < 50,0
0
inches (30 cm) for appliances > 50,00 0 Btuh (15
K = Clearance to a mechanical air su pply inlet 6 Feet (1.83 m) 3 Feet (91 cm) above if within 10 feet (3 m) h or
i
L = Clearance above paved sidewalk o r paved
driveway located on public proper ty
7 Feet (2.13 m) † Clearance in accordance with local inst allation c
o
requirements of the gas supplier.
M = Clearance under veranda, porch , deck, or
balcony
12 Inches (30 cm) ‡ Clearance in accordance withlocal inst allation c
o
requirements of the gas supplier.
¹ In accordance with the current CSA B 149.1, Natural Gas and Propane In stallation Code.
² In accordance with the current ANS I Z223.1/NFPA 54, National Fuel Gas Code.
† A vent shall not terminate directl y above a sidewalk or paved driveway th at is located between two single fami ly dwellings and serves both dwellin gs.
‡ Permitted only if veranda, porch, deck, or balcony is fully open on a m inimum of two sides beneath the floor.
* For clearances not specified in ANSI Z223.1/NFPA 54 or CSA B149.1 , one of the following shall be indicated :
a.) A minimum clearance value determined by testin g in accordance with section 4.7.3, 6.5.5, 8.5.5; or;
b.) A reference to the fo llowing footnote:
“Clearance in accordance with local installation codes and the requirem ents of the gas supplier.”