Rinnai CU199i - Combustion Air

34 Rinnai Tankless Water Heater Installaon and Operaon Manual
Important: Combuson air must be free of corrosive chemicals. Do not provide combuson air from corrosive
environments. Appliance failure due to corrosive air is not covered by warranty.
For applicaons containing corrosive indoor air, this appliance must be installed as direct vent. DO NOT use room air in
applicaons where combuson air contains acid forming chemicals such as sulfur, uorine and chlorine. These
chemicals have been found to cause rapid damage and decay and can become toxic when used as combuson air in
gas appliances. Such chemicals can be found in, but not limited to bleach, ammonia, cat lier, aerosol sprays, cleaning
solvents, varnish, paint and air fresheners. Do not store these products or similar products in the vicinity of this water
heater.
Unconned Space
An unconned space is dened in Naonal 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 rang of all appliances installed in
that space. Rooms communicang directly with the space in which the appliances are installed, through openings not
furnished with doors, are considered a part of the unconned space.” If the “unconned space” containing the
appliance(s) is in a building with ght construcon, addional outside air may be required for proper operaon.
Outside air openings should be sized the same as for a conned space.
Conned Space
A conned space is dened in the Naonal Fuel Gas Code, ANSI Z223.1/NFPA 54 as "a space whose volume is less than
50 cubic feet per 1000 Btu/hr (4.8 m3 per kW per hour) of the aggregate input rang of all appliances installed in that
space." Examples include a small room, closet, alcove, ulity room, etc. A conned space must have two combuson
air openings. Size the combuson air openings based on the BTU input for all gas ulizaon equipment in the space
and the method by which combuson air is supplied.
Using Indoor Air For Combuson: When using air from other room(s) in the building, the total volume of the room(s)
must be of adequate volume (Greater than 50 cubic feet per 1000 Btu/hr). Combuson air openings between joining
rooms must have at least 1 square inch of free area for each 1000 Btu/h, but not less than 100 square inches each.
Using Outdoor Air For Combuson
Outdoor air can be provided to a conned space through two permanent openings, one commencing within 12 in.
(0.30 m) of the top and one commencing within 12 in. (0.30 m) of the boom, of the conned space. The openings
shall communicate to the outside by one of two ways.
When communicang directly with the outdoors through horizontal ducts, each opening shall have a minimum free
area of 1 in
2
/2000 Btu/hr (1100 mm
2
/kW) of total input rang of all appliances in the conned space.
Note: If ducts are used, the cross seconal area of the duct must be greater than or equal to the required free area of
the openings to which they are connected.
This water heater requires adequate combuson air for venlaon and diluon of ue gases. Failure to provide
adequate combuson air can result in unit failure, re, explosion, serious bodily injury or death. Use the following
methods to ensure adequate combuson air is available for correct and safe operaon of this water heater.
WARNING
Combuson Air
Non-Direct Vent (Room Air)
2