12
6. Intake Venting
1. Be certain adequate air is available for combustion and ventilation.
a.)
Boiler located in unconfined space:
Installation in large areas, such as basements, can usually be assumed to
provide sufficient air.
b.)
Boiler located in confined space : (See Figure A. on page 14)
If all air for combustion and ventilation is to come from within the building:
Two (2) openings shall be provided with one (1) opening commencing within 12
inches of the ceiling and one (1) opening commencing within 12 inches of the floor of
the enclosure. These openings shall not be located closer than 3 inches from either
the top or bottom of the enclosure and shall be open to areas connecting freely
with the outdoors. The area of each opening shall not be less than one square inch
per 1000 BTU/HR. of total input rating of all appliances within the enclosure; with a
minimum of 100 square inches for each opening.
If all the air for combustion and ventilation is to come from outside the building:
Two (2) openings shall be provided with one opening commencing within 12
inches of the top and an opening commencing within 12 inches of the bottom of
the enclosure. These openings shall not be located closer than 3 inches from either
the top or bottom of the enclosure, and shall connect directly or by ducts too the
outdoors. The area of each opening shall be equal to one square inch per 4000 BTU/
HR of total input rating. If ducts are used to convey the air, vertical ducts require
areas of one square inch per 4000 BTU/HR. Horizontal ducts require one square inch
per 2000 BTU/HR. Ducts shall have the same cross sectional area as the full area of
the louver openings.
The upper opening is essential for maintenance of proper air circulation with
the boiler and to maintain proper control temperatures. When a duct is used for
ventilation, check for louver free net area and correct for screen resistance to ensure
that the sufficient ventilation area has been satisfied. DO NOT INSTALL THE BOILER
UNTIL PROPER COMBUSTION AIR HAS BEEN ARRANGED.
