a = clearance to the termination frame above grade, veranda, porch, deck,
or balcony [16 inches (41 cm) minimum]
B = clearance to door, or sides and top of window, that may be opened [16
inches (41 cm) minimum for appliances ≤100 000 BTU/H (30kW)]
C = clearance to bottom of window that may be opened horizontally [36 inches
(92 cm) minimum for appliances ≤100 000 BTU/H (30kW)]
D = no clearance to permanently closed window when installed with approved
glass penetration termination
E = clearance to permanently closed window [16 inches 41 cm recommended
to prevent condensation on window]
F = vertical clearance to ventilated soffit located above the termination within a
horizontal distance of 2 feet (61 cm) from the centreline of the termination
[22 inches (56 cm) minimum]
G = clearance to unventilated soffit [16 inches (41 cm) minimum to non-
combustibles] [22 inches (56 cm) minimum to combustibles]
H = clearance to outside corner [9 inches (23 cm) minimum]
I =
clearance to inside corner [12 inches (31 cm) minimum]
J = * not to be installed above a meter/regulator assembly within
40" (103 cm) horizontally from the centre line of the regulator
K = clearance to service regulator vent outlet [3 feet minimum in the United
States] [*6 feet (1.8 m) minimum in Canada]
L = clearance to non-mechanical air supply inlet to building or the combustion
air inlet to any other appliance [16 inches (41 cm) minimum for appliances
≤100 000 BTU/H (30kW)]
M = clearance to mechanical air supply inlet [*6 feet (1.8 m) minimum]
N =
clearance above paved sidewalk or a paved driveway located on public
†
property [*7 feet (2.1 m) minimum]
P = clearance under veranda, porch, deck, or balcony [16 inches (41 cm) mini-
mum
to non-combustibles] [22 inches (56 cm) minimum
‡
XG0146 - 042811
Appendix
Q = clearance above a roof [24 inches (61 cm) minimum]
R = clearance to adjacent walls and neighboring buildings
[18 inches (46 cm) minimum]
S = clearance from corner in recessed location [12 inches (31 cm) minimum]
T = maximum depth in recessed location [48 inches (122 cm) minimum]
U = minimum width for back wall of recessed location [24 inches (61 cm)
minimum]
V = no horizontal clearance between the frames of two terminations that
are level.
W = horizontal clearance between the frames of two terminations that are
not level. [36 inches (92 cm) minimum]
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 has an open side that
‡
is equal to or greater than the depth of the enclosed area
*
as specified in CGA B149 Installation Codes. Note: local Codes or
Regulations may require different clearance.
to combustibles]
‡
H*34DF Indoor Gas Fireplace
appendix a: Venting Terminations
Page 33