Horizontal Termination Clearance
Figure 15. Vent Terminal Clearances - National Fuel Gas Code.
A = Clearance above grade, veranda, porch , deck, or balcony :
*12 inches (30 cm) minimum.
B = Clearance to window or door that may be opened: 9 inches (23 cm) min./U.S. *12 inches (30 cm) min./ CAN
We recommend 12 inches minimum to help prevent condensation on the window.
C = Clearance to permanently closed window: 9 inches (23 cm) min./U.S. *12 inches (30 cm) min./ CAN
We recommend 12 inches minimum to help prevent condensation on the window.
D = Vertical clearance to ventilated soffit located above the terminal within a horizontal distance of 2 feet (60 cm) from the centerline of the terminal: 18 inches
(46 cm) minimum.
E = Clearance to unventilated soffit: 12 inches (46 cm) minimum.
F = Clearance to outside corner: 9 inches (23 cm) min. Jøtul N.A. strongly recommends 12 inches (30 cm), particularly where windy conditions are prevalent.
G = Clearance to inside corner: 6 inches (16 cm) minimum. Jøtul N.A. strongly recommends 12 inches (30 cm), particu- larly where windy conditions are prevalent.
H = *Not to be installed above a meter/regulator assembly within 3 feet (90 cm) horizontally from the centerline of the regulator.
I = Clearance to service regulator vent outlet: U.S. - 3 feet
CAN. 6 feet (1.8 m) minimum.
J = Clearance to nonmechanical air supply inlet to building or the combustion air inlet to any other appliance: *12 inches (30 cm) minimum.
K = Clearance to a mechanical air supply inlet: *6 feet (1.8 m) minimum.
L = ** Clearance above paved sidewalk or a paved driveway located on public property: *7 feet (2.1 m) min.
M = Clearance under veranda, porch, deck, or balcony: *12 inches (30 cm) minimum. 1
*As specified in CGA B149 Installation Codes. Note: Local Codes and Regulations may require different clearances.
**A vent shall not terminate directly above a sidewalk or driveway which is located between two single family dwellings and serves
both dwellings.*
1Only permitted if veranda, porch, deck, or balcony, is fully open on a minimum of two sides beneath the floor.*
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