Rinnai RH180 Installation Fundamentals page 27

Vent Guidelines: Combustion air
Using Outdoor Air For Combustion:
Outdoor air can be provided to a confined space through two permanent openings, one
commencing within 12 inch (300 mm) of the top and one commencing within 12 inches (300 mm)
of the bottom, of the confined space. The openings shall communicate to the outside by one of two
ways.
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