Confined Space

AIR FOR COMBUSTION AND VENTILATION

Continued

PROVIDING ADEQUATE VENTILATION

The following is exerpts from National Fuel Gas Code. NFPA 54/ANSI Z223.1, Section 5.3, Air for Combustion and Ventilation.

All spaces in homes fall into one of the three following ventilation classifications:

1. Unusually Tight Contruction; 2. Unconfined Space; 3. Confined Space.

The information on pages 5 through 8 will help you classify your space and provide adequate ventilation.

Unusually Tight Construction

The air that leaks around doors and windows may provide enough fresh air for combustion and ventilation. However, in buildings of unusually tight construction, you must provide additional fresh air.

Unusually tight construction is defined as construction where:

a.walls and ceilings exposed to the outside atmosphere have a continu- ous water vapor retarder with a rating of one perm or less with open- ings gasketed or sealed and

b.weather stripping has been added on openable windows and doors and

c.caulking or sealants are applied to areas such as joints around window and door frames, between sole plates and floors, between wall-ceiling joints, between wall panels, at penetrations for plumbing, electrical, and gas lines, and at other openings.

If your home meets all of the three criteria above, you must provide addi- tional fresh air. See Ventilation Air From Outdoors, page 8.

If your home does not meet all of the three criteria above, proceed to page 7.

Unconfined Space

The National Fuel Gas Code, ANSIZ223.1, 1992, Section 5.3 defines uncon- fined space as having a minimum air volume of 50 cubic feet (127 cubic cm) for each 1000 Btu/Hr input rating of all appliances in the space (cubic feet equals length x width x height of space). Include adjoining rooms only if there are doorless passageways or ventilation grills between the rooms.

The National Fuel Gas Code, ANSIZ223.1, 1992, Section 5.3 defines confined space as having an air volume of less than 50 cubic feet (127 cubic cm) for each 1000 Btu/Hr input rating of all appliances in the space (cubic feet equals length x width x height of space). Include adjoining rooms only if there are doorless passageways or ventilation grills between the rooms.

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