Raypak 0195A Venting Connections, Model No, Sq. in. of Each Free Area, Connector, Horizontal

1.The heater must be provided with adequate sup- ply of air for proper combustion and ventilation in accordance with Sec. 5.3 of the latest edition of the National Fuel Gas Code, ANSI Z223.1, or applicable provisions of the local building codes.

2.If the heater room is located against an outside wall and air openings can communicate directly with the outdoors, the TWO openings on the out- side wall must each have a net free area, in square inches as shown in Table D.

Model No.	Sq. in. of Each Free Area
0090	24
0135	35
0195	50

Table D: Minimum Net Free Area

Location of the openings is the same as in the pre- vious case - that is, within 12 inches of the top, and within 12 inches of the bottom of the enclo- sure. If horizontal ducts are used, the area must be doubled and the duct area shall not be less than the area of the openings they connect, and in no case shall the smallest dimension be less than 3 inches.

Venting Connections

Vent piping the same size or larger than the draft hood outlet is recommended, however, when the total vent height is at least ten (10) feet (draft hood relief open- ing to vent terminal), the vent pipe size may be reduced as specified in the National Fuel Gas Code, ANSI Z 223.1. As much as possible avoid long hori- zontal runs of vent pipe and too many elbows.

If installation requires horizontal runs, the vent pipe must have a minimum of 1/4 inch per foot rise and should be supported at not more than five foot inter- vals. Plumbers tape, crisscrossed, will serve to space both horizontal and vertical piping. Maximum vent con- nector horizontal length shall be 1-1/2 feet (18 inches) for each inch of connector diameter as shown in Table E.

Gas vents supported only by the flashing and extend- ing above the roof more than five feet should be securely guyed or braced to withstand snow and wind loads. We recommend use of insulated vent pipe spacer through the roofs and walls.

	Vent	Max.
Model No.	Connector	Horizontal
	Diameter (in.)	Length (ft)
0090	5	7.5
0135	6	9
0195	7	10.5

Table E: Vent Piping Specifications

For protection against rain or blockage by snow, the vent pipe must terminate with a listed vent cap which complies with the local codes or, in the absence of such codes, to the latest edition of the National Fuel Gas Code, ANSI Z223.1.

The discharge opening must be a minimum of two feet vertically from the roof surface and at least two(2) feet higher than any part of the building within ten (10) feet. Vent stack shall be at least five (5) feet in vertical height above the drafthood outlet. The vent cap loca- tion shall have a minimum clearance of four (4) feet horizontally from, and in no case above or below, unless a 4-foot horizontal distance is maintained, from electric meters, gas meters regulators and relief equip- ment.

The weight of the vent stack or chimney must not rest on heater draft hood. Support must be provided in compliance with applicable codes. The heater top and draft hood must be readily removable for maintenance and inspection. Vent pipe should be adequately sup- ported to maintain proper clearances from combustible construction.

Type "B" double wall or equivalent vent pipe is recom- mended. However single wall metal vent pipe may be used as specified in the latest edition of the National Flue Gas Code ANSI Z223.1.

For connections to gas vents or chimneys, vent instal- lations shall be in accordance with Part 7, Venting of Equipment, of the National Fuel Gas Code, ANSI Z223.1, or applicable provisions of the local building codes.

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