Raypak 503-2003 manual Vent Terminal Location, Canada Installations, U.S. Installations

SECTION C: Installation

Vent Terminal Location

NOTICE: During winter months check the vent cap and make sure no blockage occurs from build-up of snow or ice.

1.Condensate can freeze on the vent cap. Frozen condensate on the vent cap can result in a blocked flue condition.

2.Give special attention to the location of the vent termination to avoid possibility of property dam- age or personal injury.

3.Gases may form a white vapor plume in winter. The plume could obstruct a window view if the termination is installed near windows.

4.Prevailing winds, in combination with below- freezing temperatures, can cause freezing of con- densate and water/ice build-up on buildings, plants or roofs.

5.The bottom of the vent terminal and the air intake shall be located at least 12 in. above grade, includ- ing normal snow line.

6.Un-insulated single-wall Category IV metal vent pipe shall not be used outdoors in cold climates for venting gas-fired equipment without insulation.

7.Through-the-wall vents for Category IV appli- ances shall not terminate over public walkways or over an area where condensate or vapor could cre- ate a nuisance or hazard or could be detrimental to the operation of regulators, relief valves, or other equipment.

8.Locate and guard vent termination to prevent acci- dental contact by people or pets.

9.DO NOT terminate vent in window well, stairwell, alcove, courtyard or other recessed area.

10.DO NOT terminate above any door, window, or gravity air intake. Condensate can freeze, causing ice formations.

11.Locate or guard vent to prevent condensate from damaging exterior finishes. Use a rust-resistant sheet metal backing plate against brick or masonry surfaces.

12.DO NOT extend exposed vent pipe outside of building beyond the minimum distance required for the vent termination. Condensate could freeze and block vent pipe.

U.S. Installations

Refer to the latest edition of the National Fuel Gas Code.

Vent termination requirements are as follows:

1.Vent must terminate at least 4 ft below, 4 ft hori- zontally from or 1 ft above any door, window or gravity air inlet to the building.

2.The vent must not be less than 7 ft above grade when located adjacent to public walkways.

3.Terminate vent at least 3 ft above any forced air inlet located within 10 ft.

4.Vent must terminate at least 4 ft horizontally, and in no case above or below unless 4 ft horizontal distance is maintained, from electric meters, gas meters, regulators, and relief equipment.

5.Terminate vent at least 6 ft away from adjacent walls.

6.DO NOT terminate vent closer than 5 ft below roof overhang.

7.The vent terminal requires a 12 in. vent terminal clearance from the wall.

8.Terminate vent at least 1 ft above grade, including normal snow line.

9.Multiple direct vent installations require a 4 ft clearance between the ends of vent caps located on the same horizontal plane.

Canada Installations

Refer to latest edition of B149.1.

A vent shall not terminate:

1.Directly above a paved sidewalk or driveway which is located between two single-family dwell- ings and serves both dwellings.

2.Less than 7 ft (2.13 m) above a paved sidewalk or paved driveway located on public property.

3.Within 6 ft (1.8 m) of a mechanical air supply inlet to any building.

4.Above a meter/regulator assembly within 3 ft (0.9

m)horizontally of the vertical centre-line of the regulator.

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