Raypak 503-2003 manual Termination

		Certified	Vent Size	Vertical Vent		Combustion Air		Air Inlet
Model		Vent		Height1(Ft)		Intake Pipe	Max. Length** (Ft)
		Material	(in.)			Material
				Min.	Max.		6” Ø	8” Ø		10” Ø
	503				15*				t
	753		6		75		45	100		N/A
						Galvanized Steel,
	1003				75
	1253	Category IV		0	40	PVC,
		(AL29-4C)				ABS,
										85 t
	1503				75
						CPVC	N/A	45
			8
	1753				75
	2003				75
*	Vent length may be extended up to 40 ft. using a barometric damper installed at 15 equivalent feet from
	the heater where the category of the vent changes from Cat IV to Cat II. NOTE: Special vent materials
1	are still required.
	Vent lengths are based on a lateral length of 2 ft. Refer to the latest edition of the NFGC for further
	details.
** Subtract 10 ft per elbow. Max. 4 elbows.
t	Adapters supplied by others.

Table L: Category IV Vertical Venting

AL29-4C vent is: 6 in. (152mm) for Models 503-1003; and 8 in. (203mm) for Models 1253-2003.

The connection from the appliance vent to the stack must be as direct as possible and shall be the same di- ameter as the vent outlet. The horizontal breaching of a vent must have an upward slope of not less than 1/4 inch per linear foot from the heater to the vent termi- nal. The horizontal portions of the vent shall also be supported for the design and weight of the material employed to maintain clearances and to prevent physi- cal damage or separation of joints.

NOTE: A vent adapter (field-supplied) may be re- quired to connect the Category IV vent to the heater.

Termination

The vent terminal should be vertical and should termi- nate outside the building at least 2 ft above the highest point of the roof that is within 10 ft. The vent cap should have a minimum clearance of 4 ft horizontally from and in no case above or below (unless a 4 ft hori- zontal distance is maintained) electric meters, gas meters, regulators and relief equipment.

The distance of the vent terminal from adjacent public walkways, adjacent buildings, open windows and building openings must be consistent with the NFGC (U.S.) or B149 (Canada). Gas vents supported only by flashing and extended above the roof more than 5 ft should be se-curely guyed or braced to withstand snow and wind loads.

Fig. 23: Vertical Venting

CAUTION: A listed vent cap terminal suitable for connection to the Cat IV vent materials, adequately sized, must be used to evacuate the flue products from the building.

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