Raypak B-195 installation instructions Additional requirements when venting through a sidewall

All horizontal runs of the vent pipe shall have a minimum rise of 1/4" per foot of length and should be supported at maximum intervals of 5 feet (for Canada, 3 feet) and at each point where an elbow is used.

For horizontal venting, the total length of 4-inch diameter pipe shall not exceed 30 feet with up to two 90° elbows and 1 termination vent. For each additional elbow, reduce the total pipe length by 10 feet. The minimum length, in either case, is 2 feet with two elbows ending in a termination vent. For vertical venting, the lengths described above should be fol- lowed, with a termination vent at the top. The minimum length is 5 feet with up to two elbows and a termination vent.

For sidewall venting, locate the heater as close as possible to the wall being used. The maximum and minimum wall thickness is determined by the wall thimble available from the vent manufacturer. Refer to the vent manufacturer installation instructions.

Additional requirements when venting through a sidewall:

1.The vent terminal shall be located at least three feet above any forced air inlet located within ten feet;

or at least four feet below, four feet horizontally from, or one foot above any door, window, or gravity air inlet into any building.

It shall also have a minimum horizontal clearance of four feet from electric meters, gas meters, regulator and relief equipment.

2.The vent terminal shall be located not less than seven feet above grade when it is adjacent to public walkways.

3.The bottom of the vent terminal shall be located at least twelve inches above grade or ground, or normally expected snow accumulation level. The snow level may be higher on walls exposed to prevailing winds.

4.Avoid areas where local experience indicates that condensate drippage may cause problems such as above planters, patios, or over public walk- ways, or over an area where condensate or vapor could create a nuisance or hazard, or could be detrimental to the operation of regulators, relief valves, or other equipment.

The gas booster heater may be vented 3 ways:

1.Through the sidewall, or the ceiling, as discussed previously.

2.Into the exhaust system. (See illustration on page

6)Vent pipe must not penetrate filter.

When the unit is vented into the exhaust system, an electrical inter-lock must be provided to allow the flow of gas to the booster heater burner ONLY when the exhaust system is energized.

3.Free vented into a room or space where other gas fired equipment is installed, provided that one or more of the other installed equipment is furnished with a venting system or other approved means for removing the vent gases so the aggregate input of the remaining unvented equipment, including the booster heater, does not exceed 20 BTU per hour per cubic foot of volume. The volume of a room or space directly connected by a doorway, archway or other opening of comparable size that cannot be closed, may be included in the calculations. Refer to the National Fuel Gas Code ANSI Z223.1, NFPA 54.

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