| VENT TERMINAL | AIR SUPPLY INLET | AREA WHERE TERMINAL IS NOT PERMITTED | ||
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| Canadian Installations1 |
| US Installations2 |
A = | Clearance above grade, veranda, porch, | 12 inches (30 cm) |
| 12 inches (30 cm) | |
| deck, or balcony |
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B = | Clearance to window or door that may be | 6 inches (15 cm) for appliances 10,000 | 6 inches (15 cm) for appliances 10,000 | ||
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| Btuh (3 kW), 12 inches (30 cm) for | Btuh (3 kW), 9 inches (23 cm) for | |
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| appliances > 10,000 Btuh (3 kW) and | appliances > 10,000 Btuh (3 kW) and | |
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| 100,00 Btuh (30 kW), 36 inches (91 cm) | 50,000 Btuh (15 kW), 12 inches (30 cm) | |
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| for appliances >100,00 Btuh (30 kW) | for appliances > 50,000 Btuh (15 kW) | |
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C = | Clearance to permanently closed window | * |
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D = | Vertical clearance to ventilated soffit |
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| located above the terminal within a |
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| horizontal distance of 2 feet (61 cm) from |
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| the center line of the terminal |
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E = | Clearance to unventilated soffit |
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F = | Clearance to outside corner |
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G = | Clearance to inside corner |
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H = | Clearance to each side of center line |
| 3 feet (91 cm) within a height 15 feet | * | |
| extended above meter/regulator assembly | above the meter/regulator assembly | |||
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I = | Clearance to service regulator vent outlet | 3 feet (1.83 m) |
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J = | Clearance to nonmechanical air supply inlet | 6 inches (15 cm) for appliances 10,000 | 6 inches (15 cm) for appliances 10,000 | ||
| to building or the combustion air inlet to any | Btuh (3 kW), 12 inches (30 cm) for | Btuh (3 kW), 9 inches (23 cm) for | ||
| other appliance |
| appliances > 10,000 Btuh (3 kW) and | appliances > 10,000 Btuh (3 kW) and | |
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| 100,00 Btuh (30 kW), 36 inches (91 cm) | 50,000 Btuh (15 kW), 12 inches (30 cm) | |
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| for appliances >100,00 Btuh (30 kW) | for appliances > 50,000 Btuh (15 kW) | |
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K = | Clearance to a mechanical air supply inlet | 6 feet (1.83 m) |
| 3 feet (91 cm) above if within 10 feet | |
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| (3 m) horizontally |
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L = | Clearance above paved sidewalk or paved | 7 feet (2.13 m) † |
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| driveway located on public property |
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M = | Clearance under veranda, porch deck, or | 12 inches (30 cm) ‡ |
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| balcony |
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1In accordance with the current CSA B149.1 Natural Gas and Propane Installation Code
2In accordance with the current ANSI Z223.1 / NFPA 54 National Fuel Gas Code
†A vent shall not terminate directly above a sidewalk or paved driveway that is located between two single family dwellings and serves both dwellings.
‡ Permitted only if veranda, porch, deck, or balcony is fully open on a minimum of two sides beneath the floor.
*For clearances not specified in ANSI Z223.1 / NFPA 54 or CSA B149.1, the following statement shall be included:
“Clearance in accordance with local installation codes, and the requirements of the gas supplier and the manufacturer’s installation instructions.”
Figure 19. Vent Termination Clearances for Direct Vent Furnaces
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