Minnesota Administrative Rules
Agency 151 - Labor and Industry Department
Chapter 1346 - MINNESOTA MECHANICAL AND FUEL GAS CODES
MINNESOTA MECHANICAL CODE
Part 1346.0703 - SECTION 703 OUTDOOR AIR
Universal Citation: MN Rules 1346.0703
Current through Register Vol. 49, No. 13, September 23, 2024
IMC Sections 703.1 through 703.1.2.2 are amended to read as follows:
703.1 All air from the outdoors. Where all combustion and dilution air is to be provided by outdoor air, the required combustion and dilution air shall be obtained by opening the room to the outdoors. Openings connecting the room to the outdoor air shall comply with IMC Sections 703.1.1 through 703.1.2.2.
703.1.1
One permanent opening
method. When any natural draft equipment is installed, one permanent
opening, commencing within 12 inches (300 mm) of the bottom of the enclosure,
shall be provided. When other than natural draft equipment is installed, one
permanent opening, commencing within 12 inches (300 mm) of the top of the
enclosure, shall be provided. The opening shall directly communicate with the
outdoors or shall communicate through a vertical or horizontal duct to the
outdoors or spaces that freely communicate with the outdoors and shall have a
minimum free area of 1 inch2/3,000 Btu/hr (700
mm2/kW/hr) of the total input rating of all
equipment located in the enclosure.
703.1.2
Two permanent openings
method. Two openings shall be provided, one within 1 foot (305 mm) of
the ceiling of the room and one within 1 foot (305 mm) of the floor.
703.1.2.1
Size of horizontal
openings. The net free area of each opening, calculated in accordance
with IMC Chapter 709 and connected to the outdoors through a horizontal duct,
shall be a minimum of 1 square inch per 2,000 Btu/h (1,100
mm2/kW) of combined input rating of the fuel-burning
appliances drawing combustion and dilution air from the room. The
cross-sectional area of the duct shall be equal to or greater than the required
size of the opening.
703.1.2.2
Size of vertical openings. The net free area of each opening,
calculated in accordance with IMC Chapter 709 and connected to the outdoors
through a vertical duct, shall be a minimum of 1 square inch per 4,000 Btu/h
(550 mm2/kW) of combined input rating of the
fuel-burning appliances drawing combustion and dilution air from the room. The
cross-sectional area of the duct shall be equal to or greater than the required
size of the opening.
Statutory Authority: MS s 16B.59; 16B.61; 16B.64; 326B.101; 326B.106; 326B.13
Disclaimer: These regulations may not be the most recent version. Minnesota may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.
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