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FIGURE 23
VENT TERMINATION CLEARANCES
FOR INSTALLATIONS IN THE USA AND CANADA*
A − Clearance above grade − 12 in. (305mm) minimum.
B − Clearance to window or door that may be opened −
for vent installations in USA − 12 in. (305mm) minimum.
for vent installations in Canada − 12 in. (305mm) minimum
for appliances 100,000 Btuh (30 kW);
36 in. (0.9m) minimum for appliances > 100,000 Btuh (30
kW).
C − Do not position terminations directly under roof eaves.
D − Clearance to electric meters, gas meters, regulators, and
relief equipment −
for vent installations in USA − 48 in (1219mm) minimum.
for vent installations in Canada − see current edition of CSA
B149 Code.
E − Clearance to non−mechanical air supply inlet or outlet
for vent installations in USA − 48 in. (1219mm) minimum
horizontal and below, 12 in. (305mm) minimum above.
for vent installations in Canada − 12 in. (305mm) minimum
for appliances 100,000 Btuh (30 kW);
36 in. (0.9m) minimum for appliances > 100,000 Btuh (30
kW).
F − Clearance to mechanical air supply inlet −−
for vent installations in USA − 36 in. minimum (914mm).
G − Clearance to mechanical air supply inlet −−
for vent installations in Canada − 72 in. (1829mm) mini-
mum.
H − Do not point terminations into recessed areas such as win-
dow wells, stairwells or alcoves.
J − Do not position terminations directly above a public walk-
way.
* Note −
(I) Dimensions are from the current edition of The National Fuel Gas Code − ANSI-Z223.1/NFPA 54 for USA installa-
tions. In Canada, refer to current edition of CSA B149 installation codes. Local codes or regulations may require different
clearances.
less than
10 ft (3.048M)
C
D
D
E
F
G
(II) In Non-Direct Vent installations, combustion air is taken from indoors and the flue gases are discharged to the outdoors.
− G71MPP VENT TERMINATION
− AIR INLET OF OTHER APPLIANCE