AIR FOR COMBUSTION
AND VENTILATION
WARNING: This heater shall notbeinstalledinaconfinedspace or unusually tight construction unless provisions are provided foradequatecombustionandven- tilation air. Read the following in- structions to insure proper fresh air for this and other
Today’s homes are built more energy efficient than ever. New materials, increased insulation, and new construction methods help reduce heat loss in homes. Home owners weather strip and caulk around windows and doors to keep the cold air out and the warm air in. During heating months, home owners want their homes as airtight as possible.
While it is good to make your home energy effi- cient, your home needs to breathe. Fresh air must enter your home. All
Exhaust fans, fireplaces, clothes dryers, and fuel burning appliances draw air from the house to operate. You must provide adequate fresh air for these appliances. This will insure proper venting of vented
PROVIDING ADEQUATE
VENTILATION
The following are excerpts from National Fuel Gas Code, ANSI Z223.1/NFPA 54, Section 5.3, Air for Combustion and Ventilation.
All spaces in homes fall into one of the three fol- lowing ventilation classifications:
1.Unusually Tight Construction
2.Unconfined Space
3.Confined Space
The information on pages 6 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 ven- tilation. 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 out- side atmosphere have a continuous water vapor retarder with a rating of
one perm (6 x
b.weather stripping has been added on openable windows and doors and
c.caulking or sealants are applied to ar- eas such as joints around window and door frames, between sole plates and floors, between
If your home meets all of the three criteria above, you must provide additional fresh air. See Ventilation Air From Outdoors, page 6.
If your home does not meet all of the three criteria above, proceed to Deter- mining
Confined Space and Unconfined Space The National Fuel Gas Code, ANSI Z223.1/NFPA 54 defines a confined space as a space whose vol- ume is less than 50 cubic feet per 1,000 Btu per hour (4.8 m3 per kw) of the aggregate input rating of all appliances installed in that space and an un- confined space as a space whose volume is not less than 50 cubic feet per 1,000 Btu per hour (4.8 m3 per kw) of the aggregate input rating of all ap- pliances installed in that space. Rooms communi- cating directly with the space in which the appli- ances are installed*, through openings not fur- nished with doors, are considered a part of the un- confined space.
*Adjoining rooms are communicating only if there are doorless passageways or ventilation grills be- tween them.
DETERMINING FRESH-AIR FLOW FOR HEATER LOCATION
Determining if You Have a Confined or Unconfined Space
Use this work sheet to determine if you have a confined or unconfined space.
Space: Includes the room in which you will install fireplace plus any adjoining rooms with doorless pas- sageways or ventilation grills between the rooms.
1.Determine the volume of the space (length x width x height).
Length x Width x Height =__________cu. ft. (volume of space)
Example: Space size 20 ft. (length) x 16 ft. (width) x 8 ft. (ceiling height) = 2560 cu. ft. (vol- ume of space)
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