Combustion Air Requirements - Rinnai REU-VA1320WF-US Operation And Installation Manual

Combustion Air Requirements

This water heater 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 water
heater.
Important: Combustion air must be free of corrosive chemicals. Do not provide combustion air from corrosive
environments. Appliance failure due to corrosive air is not covered by warranty.
Combustion air must be free of acid forming chemical 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 this water heater.
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 1000 Btu/hr (4.8 m3 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 appliance(s) 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.
(10.6m)
(7.6m)
(7.6m)
Unconfined Space Unconfined Space
91,300 BTU Water Heater and a
100,000 BTU Furnace
RH180 Manual 13