EXTERIOR HORIZONTAL VENT TERMINATION CLEARANCE REQUIREMENTS
*See Item D in the Text Below.
Exterior Wall | Center Line |
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*18” |
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Horizontal |
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Termination |
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18” | Ventilated Soffit |
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Inside Corner |
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| = 9” in U.S. | |||
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Detail D |
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| = 12” in Canada | |||
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B |
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L |
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| V | Operable |
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| Fixed |
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| Closed |
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F | V | Window |
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X = Air Supply Inlet |
| V = Vent Terminal | = Area where Terminal is not Permitted |
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H
D | E |
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M
V
I
V
6
| Canadian Installation* | US Installation** |
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A = Clearance above grade, veranda, porch, | 12 inches (30cm)* | 12 inches (30cm)** |
deck, or balcony. |
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B = Clearance to window or door that may be | 6 in (15cm) for appliances | 6 in (15cm) for appliances |
opened. | < 10,000 Btuh (3kW), 12 in (30cm) | < 10,000 Btuh (3kW), 9 in (23cm) |
| for appliances > 10,000 Btuh (3kW) and | for appliances > 10,000 Btuh (3kW) and |
| < 100,000 Btuh (30kW), 36 inches (91cm) | < 50,000 Btuh (15kW), 12 inches (30cm) |
| for appliances > 100,000 Btuh (30kW)* | for appliances > 50,000 Btuh (15kW)** |
C = Clearance to permanently closed window | 12" (305mm) recommended to prevent | 9" (229mm) recommended to prevent |
| window condensation | window condensation |
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D = Vertical clearance to ventilated soffit | 18" (458mm) | 18" (458mm) |
located above the terminal within a horizontal |
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distance of 18 inches (458mm) from the center |
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line of the terminal |
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E = Clearance to unventilated soffit | 12" (305mm) | 12" (305mm) |
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F = Clearance to outside corner | 5" (12.7cm) minimum | 5" (12.7cm) minimum |
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G = Clearance to inside corner | 6" (15.2cm) minimum | 6" (15.2cm) minimum |
H = Clearance to each inside of center line | 3 feet (91cm) within a height of 15 feet | 3 feet (91cm) within a height of 15 feet |
extended above meter/regulator assembly | above the meter/regulator assembly* | above the meter/regulator assembly** |
I = Clearance to service regulator vent outlet | 3 feet (91cm)* | 3 feet (91cm)** |
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J = Clearance to nonmechanical air supply inlet | 6 in (15cm) for appliances | 6 in (15cm) for appliances |
to building or the combustion air inlet to any | < 10,000 Btuh (3kW), 12 in (30cm) | < 10,000 Btuh (3kW), 9 in (23cm) |
other appliance | for appliances > 10,000 Btuh (3kW) and | for appliances > 10,000 Btuh (3kW) and |
| < 100,000 Btuh (30kW), 36 inches (91cm) | < 50,000 Btuh (15kW), 12 inches (30cm) |
| for appliances > 100,000 Btuh (30kW)* | for appliances > 50,000 Btuh (15kW)** |
K = Clearance to a mechanical air supply inlet | 6 feet (1.83m)* | 3 feet (91cm) above if within 10 feet (3m) |
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L = Clearance above paved sidewalk or paved | 7 feet (2.13m)‡ | 7 feet (2.13m)‡ |
diveway located on public property |
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M = Clearance under veranda, porch, deck or | 12 inches (30cm)*‡ | 12 inches (30cm)‡ |
balcony |
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*In accordance with the current
**In accordance with the curent ANSI SZ223.1/NFPA 54 National Fuel Gas Codes.
‡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 2 sides beneath the floor:
Figure 8
NOTE: DIAGRAMS & ILLUSTRATIONS NOT TO SCALE.