Raypak 135A, 195A, 090A manual Ventingconnections, Ansi Z

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 outside wall must each have a net free area, in square inches as follows:

Model	Sq. In. Of Free Area
0090	24
0135	35
0195	50

Location of the openings is the same as in the previous case - that is, within 12 inches of the top, and within 12 inches of the bottom of the enclosure. 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.

VENTINGCONNECTIONS

These heaters have built-in drafthoods. Vent piping the same size or larger than the draft hood outlet is recommended; however, when the total vent height (drafthood outlet to vent terminal) is at least ten (10) feet, the vent pipe size may be reduced by one size only as specified in Chapter 10 of the latest edition of the National Fuel Gas Code, ANSI Z 223.1. As much as possible avoid long horizontal 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 less than five foot intervals. Maximum vent connector horizontal length shall be 1-1/ 2 feet (18 inches) for each inch of connector diameter as follows.

Heater Size	Vent Connector	Max Horizontal
	Diameter	Length - FT
90	5"	7.5
135	6"	9
195	7"	10.5

Gas Vents supported only by the flashing and extending 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.

For protections 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 Z 223.1.

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 location 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 equipment.

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 recommended. However single wall metal vent pipe may be used as specified in the latest edition of the National Flue Gas Code ANSI Z 223.1.

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