Figure 12b. Direct Vent Terminal Clearances
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| Canadian | US |
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| Canadian | US Installations2 |
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| Installations1 | Installations2 |
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| Installations1 |
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A= | Clearance above grade, | 12 inches | 12 inches | H= | Clearance to each side | 3 feet (91 cm) within a | *b |
| veranda, porch, deck or | (30 cm) | (30 cm) |
| of center line extended | height 15 feet (4.6 m) |
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| balcony |
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| above meter/regulator | above the |
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| assembly | meter/regulator |
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| assembly |
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B= | Clearance to widow or | 36 inches | 12 inches | I= | Clearance to service | 36 inches | *b |
| door that may be opened | (91 cm) | (30 cm) |
| regulator vent outlet or | (91 cm) |
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| oil tank vent |
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C= | Clearance to | *b | *b | J= | Clearance to non- | 36 inches | 12 inches |
| permanently closed |
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| mechanical air supply | (91 cm) | (30 cm) |
| window |
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| inlet to building or the |
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| combustion air inlet to |
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| any other appliance |
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D= | Vertical clearance to | 12 inches | 12 inches | K= | Clearance to a | 6 feet | 3 feet (.9 m) |
| ventilated soffit located | (30 cm) *a | (30 cm) *a |
| mechanical air supply | (1.83 m) | above if within |
| above the terminal within |
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| inlet |
| 10 feet (3 m) |
| a horizontal distance of 2 |
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| horizontally |
| feet (.6 m) from the |
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| center line of the |
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| terminal |
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E= | Clearance to | 12 inches | 12 inches | L= | Clearance above paved | 7 feet | *b |
| unventilated soffit | (30 cm) *a | (30 cm) *a |
| sidewalk or paved | (2.13 m) † |
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| driveway located on |
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| public property |
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F= | Clearance to outside | *b | *b | M= | Clearance under a | 12 inches (30 cm) ‡ | 12 inches (30 |
| corner |
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| veranda, porch, deck, or |
| cm) ‡ |
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| balcony |
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G= | Clearance to inside | 36 inches | 36 inches |
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| corner | (91 cm) *a | (91 cm) *a |
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1In accordance with the current
2In accordance with the current ANSI
†A vent shall not terminate directly above a sidewalk or paved driveway that is located between two
‡ Permitted only if a veranda, porch, deck or balcony is fully open on a minimum of two sides beneath the floor. *a) A minimum clearance value determined by testing in accordance with section 2.20.
*b) “Clearance in accordance with local installation codes and the requirements of the gas supplier”.
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