CODES

ADOPTS WITH AMENDMENTS:

International Mechanical Code 2009 (IMC 2009)

The provisions contained in this appendix are adopted as part of this code.

APPENDIX A

COMBUSTION AIR OPENINGS AND
CHIMNEY CONNECTOR PASS-THROUGHS

(This appendix is informative and is not part of the code.)

Figures A-1 through A-4 are illustrations of appliances located in confined spaces.

For SI: 1 square inch = 645 mm2, 1 British thermal unit per hour = 0.2931 W.

FIGURE A-1
ALL AIR FROM INSIDE THE BUILDING

NOTE: Each opening shall have a free area of not less than 1 square inch per 1,000 Btu per hour of the total input rating of all appliances in the enclosure and not less than 100 square inches.

For SI: 1 square inch = 645 mm2, 1 British thermal unit per hour = 0.2931 W.

FIGURE A-2
ALL AIR FROM OUTDOORS—INLET AIR FROM VENTILATED CRAWL SPACE AND OUTLET AIR TO VENTILATED ATTIC

NOTE: The inlet and and outlet air openings shall each have a free area of not less than 1 square inch per 4,000 Btu per hour of the total input rating of all appliances in the enclosure.

For SI: 1 foot = 304.8 mm, 1 square inch = 645 mm2, 1 British thermal unit per hour = 0.2931 W.

FIGURE A-3
ALL AIR FROM OUTDOORS THROUGH VENTILATED ATTIC

NOTE: The inlet and outlet air openings shall each have a free area of not less than 1 square inch per 4,000 Btu per hour of the total input rating of all appliances in the enclosure.

For SI: 1 foot = 304.8 mm, 1 square inch = 645 mm2, 1 British thermal unit per hour = 0.2931 W.

FIGURE A-4
ALL AIR FROM OUTDOORS THROUGH HORIZONTAL DUCTS OR DIRECT OPENINGS


NOTE: Each air duct opening shall have a free area of not less than 1 square inch per 2,000 Btu per hour of the total input rating of all appliances in the enclosure. If the appliance room is located against an outside wall and the air openings communicate directly with the outdoors, each opening shall have a free area of not less than 1 square inch per 4,000 Btu per hour or the total input rating of all appliances in the enclosure.




For SI: 1 inch = 25.4 mm.

FIGURE A-5
CHIMNEY CONNECTOR SYSTEMS

For SI: 1 inch = 25.4 mm.

FIGURE A-5—continued
CHIMNEY CONNECTOR SYSTEMS

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