Combustion Air Requirements - Rinnai RU130i Installation Instructions Manual

Combustion Air Requirements

Common Vent Applications Utilizing Room Air
Condensate Trap
6 in (152 mm)
Minimum
This rack system requires adequate combustion air for ventilation and dilution of flue gases. Failure to provide
adequate combustion air can result in unit failure, fire, explosion, serious bodily injury or death. Use the following
methods to ensure adequate combustion air is available for correct and safe operation of this rack system.
Important: Combustion air must be free of corrosive chemicals. Do not provide combustion air from corrosive
environments. System failure due to corrosive air is not covered by warranty.
Combustion air must be free of acid forming chemicals such as sulfur, fluorine and chlorine. These chemicals have been
found to cause rapid damage and decay and can become toxic when used as combustion air in gas appliances. Such
chemicals can be found in, but not limited to bleach, ammonia, cat litter, aerosol sprays, cleaning solvents, varnish,
paint, and air fresheners. Do not store these products or similar products in the vicinity of the water heater system.
Unconfined Space:
An unconfined space is defined in National Fuel Gas Code, ANSI Z223.1/NFPA 54 as "a space whose volume is not less
than 50 cubic feet per 1,000 Btu/hr (4.8 m 3 per kW per hour) of the aggregate input rating of all appliances installed in
that space. Rooms communicating directly with the space in which the appliances are installed, through openings not
furnished with doors, are considered a part of the unconfined space." If the "unconfined space" containing the system
is in a building with tight construction, additional outside air may be required for proper operation. Outside air
openings should be sized the same as for a confined space.
Confined Space:
(Small Room, Closet, Alcove, Utility Room, Etc.)
A confined space is defined in the National Fuel Gas Code, ANSI Z223.1/NFPA 54 as "a space whose volume is less than
50 cubic feet per 1,000 Btu/hr (4.8 m3 per kW per hour) of the aggregate input rating of the combined appliances
installed in that space." A confined space must have two combustion air openings. Size the combustion air openings
based on the BTU input for all gas utilization equipment in the space and the method by which combustion air is
supplied.
PVC/CPVC Common Venting Installation Instructions 18