Rinnai RU98i Installation Manual page 20

Combustion Air Requirements (Commercial Applications with C199i Only)
Louvers and Grills
When sizing the permanent opening consideration
must be taken for the design of the louvers or grills
to maintain the required free area required for all
gas utilizing equipment in the space. 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".
Example:
Wood: 10 in x 12 in x 0.25 = 30 in
Metal: 10 in x 12 in x 0.75 = 90 in
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" of the top of the confined space
and the lower opening shall be within 12" of the
bottom of the confined space. Openings must be
positioned as to never be obstructed.
Using Outdoor Air For Combustion
Outdoor air can be provided to a confined space
through two permanent openings, one commenc-
ing within 12 in. (300mm) of the top and one
commencing within 12" (300mm) of the bottom, of
the confined space. The openings shall
communicate to the outside by one of two ways.
Rinnai CVent
2
2
Vent termination per ANSI Z223.1/NFPA 54. For
clearances not specified in ANSI Z223.1/NFPA 54,
clearances are in accordance with local installation
codes and the requirements of the gas supplier.
20
(Be sure to also maintain 12" above grade or
anticipated snow level)
Exhaust