Venting Connections

2)Models 0042 and 0066 only-

When the boiler is installed in a confined space such as a utility room or closet where all air is supplied from inside the building, the boiler room must be provided with two openings, each one having a minimum net free area, in square inches as follows:

Model		Sq. In. of Free Area
0042, 0066		70

One opening shall be within 12" of the top, and the other opening within 12" of the floor. If additional gas appliances are installed in the same space, the total input of all gas appliances installed in the same space, must be considered in the calculation. Refer to Sec. 5.3.5 of the latest edition of the National Fuel Gas Code for additional requirements.

Fig.# 8198.0

NOTE:If louvers, grills or screens are used on the openings, obtain the net free area requirements from their supplier or manufacturer. If the design free area of a louver is not known nor available, it shall be assumed that wood louvers will have 20-25percent free area and metal louvers will have 60-75percent free area as shown in Sec. 5.3.5 National Fuel Gas Code.

3)If the boiler 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 as follows:

Model	(Sq. In.) Net Free Area
0042	12
0066	18
0090	24
0135	35
0180	45

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

These boilers have built-in drafthoods. Vent piping the same size or larger than the drafthood 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.

Model	Vent Connector	Max Horizontal
	Diameter	Length
42	4"	6'
66 & 90	5"	7.5'
135	6"	9'
180	7"	10.5'

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.

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 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 horizon- tally 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.