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EXTERIOR HORIZONTAL VENT TERMINATION CLEARANCES
A - Clearance above grade, veranda, porch, deck, or balcony
-- *12 in. (305mm) minimum.
B - Clearance to openable window or door -- *12 in. (305mm)
minimum.
C - Clearance to permanently closed window -- minimum 9 in.
(228mm) in the United States and 12 in. (305mm) in Canada
recommended to prevent condensation on window.
D - Vertical clearance to ventilated soffit located above the ter-
minal within a horizontal distance of 18 in. (457mm) from the
center line of the terminal -- 18 in. (457mm) minimum.
E - Clearance to unventilated soffit -- 12 in. (305mm) minimum.
F - Clearance to outside corner -- 5 in. (127mm) minimum.
G - Clearance to inside corner -- 6 in. (152mm) minimum).
H - *Not to be installed above a meter / regulator assembly with-
in 3 ft. (.9m) horizontally from the center line of the regulator.
I - Clearance to service regulator vent outlet -- 3 ft. (915mm)
in the United States and *6 ft. (1.8m) in Canada minimum.
J - Clearance to non-mechanical air supply inlet to building or
the combustion air inlet to any other appliance -- 9 in.
(228mm) in the United States and *12 in. (305mm) in Cana-
da minimum.
K - Clearance to mechanical air supply inlet -- 3 ft. (915mm) in
the United States and *6 ft. (1.8m) in Canada minimum.
L - †Clearance above paved sidewalk or a paved driveway lo-
cated on public property -- *7 ft. (2.1m) minimum.
M - ‡Clearance under veranda, porch, deck, or balcony -- 12 in.
(305mm) minimum.
N - Vent termination must not be located in a recessed area.
†A vent shall not terminate directly above a sidewalk or paved driveway which is located between two
single family dwellings and serves both dwellings.*
‡Only permitted if veranda, porch, deck, or balcony is fully open on a minimum of two sides beneath
the floor.*
*As specified in CAN/CGA B149 Installation Codes.
NOTE - Local codes or regulations may require different clearances.
FIGURE 31
