Installation Sheet
34 Rinnai Tankless Water Heater Installaon and Operaon Manual
Important: Combuson air must be free of corrosive chemicals. Do not provide combuson air from corrosive
environments. Appliance failure due to corrosive air is not covered by warranty.
For applicaons containing corrosive indoor air, this appliance must be installed as direct vent. DO NOT use room air in
applicaons where combuson 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 combuson air in
gas appliances. Such chemicals can be found in, but not limited to bleach, ammonia, cat lier, aerosol sprays, cleaning
solvents, varnish, paint and air fresheners. Do not store these products or similar products in the vicinity of this water
heater.
Unconned Space
An unconned space is dened in Naonal 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 rang of all appliances installed in
that space. Rooms communicang directly with the space in which the appliances are installed, through openings not
furnished with doors, are considered a part of the unconned space.” If the “unconned space” containing the
appliance(s) is in a building with ght construcon, addional outside air may be required for proper operaon.
Outside air openings should be sized the same as for a conned space.
Conned Space
A conned space is dened in the Naonal 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 rang of all appliances installed in that
space." Examples include a small room, closet, alcove, ulity room, etc. A conned space must have two combuson
air openings. Size the combuson air openings based on the BTU input for all gas ulizaon equipment in the space
and the method by which combuson air is supplied.
Using Indoor Air For Combuson: 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). Combuson 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 Combuson
Outdoor air can be provided to a conned 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 boom, of the conned space. The openings
shall communicate to the outside by one of two ways.
When communicang 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 rang of all appliances in the conned space.
Note: If ducts are used, the cross seconal 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 combuson air for venlaon and diluon of ue gases. Failure to provide
adequate combuson air can result in unit failure, re, explosion, serious bodily injury or death. Use the following
methods to ensure adequate combuson air is available for correct and safe operaon of this water heater.
WARNING
Combuson Air
Non-Direct Vent (Room Air)
2