Raypak 503-2003 manual Combustion Air Supply, Exhaust Configuration, Heater Venting Category

Combustion

Air Supply

Exhaust

Configuration

Heater Venting

Category

Certified Materials

Combustion Air

Inlet Material

	Vertical
From Inside Building	Venting
(Non-Direct Venting)	Horizontal Through-		Stainless Steel
	the-Wall Venting	IV
			AL29-4C
	Vertical
From Outside Building	Venting
(Direct Venting)	Horizontal Through-
	the-Wall Venting
	Table K: Venting
		Category Requirements

Galvanized Steel

PVC

ABS

CPVC

Use only the special gas vent pipes listed for use with Category IV gas burning heaters, such as the AL29-4C stainless steel vents offered by Heat Fab Inc. (800- 772-0739), Protech System, Inc. (800-766-3473), Z-Flex (800-654-5600) or American Metal Products (800-423-4270). Pipe joints must be positively sealed. Follow the vent manufacturer’s installation instructions carefully.

Support of Vent Stack

The weight of the vent stack or chimney must not rest on the heater vent connection. Support must be pro- vided in compliance with applicable codes. The vent should also be installed to maintain proper clearances from combustible materials. Use insulated vent pipe spacers where the vent passes through combustible roofs and walls.

Vent Terminal Location

NOTE: 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 ter- mination is installed near windows.

4. Prevailing winds, in combination with below-freez- ing temperatures, can cause freezing of condensate 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 create a nuisance or hazard or could be detrimen- tal 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 mason- ry 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:

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