Rinnai Tankless Water Heater Installation and Operation Manual
45
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Verify all combustion air opening sizes are correct.
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Ensure that the Combustion Air Requirements are followed that will provide sufficient
combustion air for the appliance.
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DO NOT use room air for combustion in applications where the indoor air is corrosive.
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Verify that adequate combustion air is available for all appliances installed in the space.
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Installation complies with National Fuel Gas Code, ANSI Z223.1/NFPA 54 as well as local
and state regulations therein.
Figure 41
Location
To maintain proper circulation of combustion air two
permanent openings (one upper, one lower) must be
positioned in confined spaces. The upper shall be within 12
in. (0.30 m) of the top of the confined space and the lower
opening shall be within 12 in. (0.30 m) of the bottom of the
confined space. Openings must be positioned as to never
be obstructed.
12 in.
(300 mm)
10 in.
(250 mm)
Combustion air provided to the appliance should not be taken from any area of the structure that may
produce a negative pressure (i.e. exhaust fans, powered ventilation fans).
TO PREVENT POSSIBLE PERSONAL INJURY OR DEATH DUE TO AS
-
PHYXIATION, COMMON VENTING WITH OTHER MANUFACTURER’S
INDUCED DRAFT APPLIANCES IS NOT ALLOWED.
Checklist for Combustion Air and Venting Requirements
WARNING
Louvers and Grills
Adequate combustion air is required for all gas utilizing equipment in the location. Therefore, proper
sizing of permanent openings, such as louvers or grills, must be considered to maintain the required
free area. If the free area of the louver or grill design is not available, assume wood louvers will have
25% free area and metal louvers or grills will have 75% free area. Under no circumstance should the
louver, grill or screen have openings smaller than 1/4 in.
Example for a grill with dimensions as shown in Figure 41: Wood: 10 in. x 12 in. x 0.25 = 30 in.
2
Metal: 10 in. x 12 in. x 0.75 = 90 in.
2
