N.Y.C. Admin. Code § MC 701: Section MC 701: General

701.1 Scope.

The provisions of this chapter shall govern the requirements for combustion, ventilation, and dilution air for fuel-burning appliances other than gas-fired appliances. The requirements for combustion, ventilation, and dilution air for gas-fired appliances shall be in accordance with the New York City Fuel Gas Code.

701.2 Combustion, ventilation, and dilution air required.

Every room or space containing fuel-burning appliances shall be provided with combustion, ventilation, and dilution air as required by this code. Combustion, ventilation, and dilution air shall be provided in accordance with Section 702, 703, 704, 705, 706 or 707. Direct-vent appliances or equipment that do not draw combustion air from inside of the building are not required to be considered in the determination of the combustion and dilution air requirements and shall be installed in accordance with the equipment manufacturer's instructions and listing. Combustion air requirements shall be determined based on the simultaneous operation of all fuel-burning appliances drawing combustion, ventilation, and dilution air from the room or space. Combustion, ventilation, and dilution air shall be obtained solely from the outdoors for fuel-burning appliances with an input greater than 350,000 Btu/h (102.6 kW). The room or space containing fuel-burning appliances shall comply with the requirements of Sections C402.5.3 and R402.4.4, as applicable, of the New York City Energy Conservation Code and Section 1012 of this code.

701.3 Circulation of air.

The equipment and appliances within every room containing fuel-burning appliances shall be installed so as to allow free circulation of air. Provisions shall be made to allow for the simultaneous operation of mechanical exhaust systems, fireplaces or other equipment and appliances operating in the same room or space from which combustion, ventilation, and dilution air is being drawn. Such provisions shall prevent the operation of such appliances, equipment and systems from affecting the supply of combustion, ventilation, and dilution air.

701.3.1 Makeup air for fuel burning devices.

Where exhaust fans are installed, makeup air shall be provided to replace the exhausted air. Calculations shall be provided on the construction documents to validate the use of the exhaust fan(s) and compliance with this chapter.

701.3.2 Ventilation air for fuel-burning devices.

Where ventilation air is brought in by mechanical means for heat generation mitigation, provisions must be made for proper air balance to prevent a negative or positive pressure in the boiler room and to discharge the ventilation air directly to the outside.

701.4 Crawl space and attic space.

For the purposes of this chapter, an opening to a naturally ventilated crawl space or attic space shall be considered equivalent to an opening to the outdoors.

701.4.1 Crawl space.

Where lower combustion air openings connect with crawl spaces, such spaces shall have unobstructed openings to the outdoors at least twice that required for the combustion air openings. The height of the crawl space shall comply with the requirements of the New York City Building Code and shall be without obstruction to the free flow of air.

701.4.2 Attic space.

Where combustion air is obtained from an attic area, the attic ventilating openings shall not be subject to ice or snow blockage, and the attic shall have not less than 30 inches (762 mm) vertical clear height at its maximum point. Attic ventilation openings shall be sufficient to provide the required volume of combustion air and the attic ventilation required by the New York City Building Code. The combustion air openings shall be provided with a sleeve of not less than 0.019 inch (0.48 mm) (No.26 Gage) galvanized steel or other approved material extending from the appliance enclosure to at least 6 inches (152.4 mm) above the top of the ceiling joists and insulation.

701.5 Prohibited sources.

Openings and ducts shall not connect appliance enclosures with a space in which the operation of a fan will adversely affect the flow of the combustion, ventilation, and dilution air. Combustion, ventilation, and dilution air shall not be subject to ice or snow blockage. No combustion, ventilation, and dilution air inlet shall be less than 30 inches (762 mm) above grade. Combustion, ventilation, and dilution air shall not be obtained from a hazardous location, except where the fuel-fired appliances are located within the hazardous location and are installed in accordance with this code. Combustion, ventilation, and dilution air shall not be taken from a refrigeration machinery room, except where a refrigerant vapor detector system is installed to automatically shut off the combustion process in the event of refrigerant leakage. For structures in flood hazard areas, air shall be obtained from a location complying with the additional requirements of Appendix G of the New York City Building Code.