Installation Guide

Installation & Servicing Instructions Rinnai Q-Series

Conﬁ ned Space:

(Small Room, Closet, Alcove, Utility Room, Etc.)

A conﬁ ned space is deﬁ ned in the 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 rating

of all appliances installed in that space." A conﬁ ned space must have two combustion

air openings. Size the combustion air openings based on the BTU input for all gas

utilization equipment in the space and the method by which combustion air is supplied:

Using indoor air for combustion

Using outdoor air for combustion

Louvers and Grills

When sizing the permanent opening as illustrated in ﬁ gure 24, 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 ¼”.

Example:

Wood: 10 in x 12 in x 0.25 = 30 in2

Metal: 10 in x 12 in x 0.75 = 90 in2

Location

To maintain proper circulation of combustion air two permanent openings (one upper,

one lower) must be positioned in conﬁ ned spaces. The upper shall be within 12 inches

of the conﬁ ned space and the lower opening shall be within 12 inches of the bottom

of the conﬁ ned space. Openings must be positioned as to never be obstructed.

Combustion air provided to the boiler should not be taken from any area of the structure

that may produce a negative pressure (i.e. exhaust fans, powered ventilation fans).

OUTLET AIR DUCT

INLET AIR DUCT

Gas Vent / Boiler Exhaust

BOILER

12in. MAX

PERMANENT

OPENINGS

BOILER

10"

(250mm)

12"

(300mm)

Louvers and grills ﬁ gure 24