N.Y.C. Admin. Code § MC 811: Section MC 811: Exhaust Gases from Internal Combustion Engines and Turbines

811.1 Exhaust system construction.

The exhaust system from internal combustion engines shall be constructed in accordance with NFPA 211, NFPA 37, and based on the temperature of the flue gas entering the exhaust system, and in accordance with the following:

1. The exhaust system, if factory built, shall be installed in accordance with its listing and manufacturer's instructions.

1.1. Exhaust systems with flue gas temperatures greater than 300°F (148.9°C) shall be listed to UL 103 or UL 2561 and be rated for a minimum of 60 inch w.c. (14 934.3 Pa).

1.2. Exhaust systems with flue gas temperatures not more than 300°F (148.9°C) and that are capable of causing excessive condensate production in the exhaust system shall be listed to UL 103 or UL 2561 and UL 1738 and be rated for a pressure suitable for the operating conditions.

2. The exhaust system, if field fabricated, shall be constructed of at least 3/16-inch (4.8 mm) steel, or of other equivalent metal of similar strength and resistance to the temperature and corrosive action of the exhaust gases. No lining shall be required.

3. Where the exhaust system runs inside a building, it shall be insulated adequately for the equipment operating temperature, so that the surface temperature shall be not more than 200°F (93.3°C).

4. Where the exhaust system runs inside a building outside of the room containing the equipment, it shall be enclosed in fire-rated construction with a fire rating equal to the fire rating of the construction of the room.

5. All joints shall be constructed so as to be gas tight under all operating conditions and tested in accordance with Section 810.

811.2 Emergency and standby generator discharge opening termination requirements.

The location of discharge outlets for emergency and standby generators shall comply with the requirements of NFPA 37 so that the flue gases are not directed to jeopardize the health or safety of people, overheat combustible structures, nor enter building openings in the vicinity of the outlet, nor shall the location of such openings cause the condensate leaving the outlet to come into contact with people.

811.2.1 Interference.

No discharge opening shall be located and constructed so as to interfere with the proper functioning of other openings in the same building or adjoining buildings, to interfere unreasonably with the occupants of the same building or adjoining buildings, or with the general public, or to create a fire or health hazard.

811.2.2 Chimneys.

The exhaust pipe may be connected to a chimney used for other equipment, provided that the operation of the engine does not adversely affect the operation of the other equipment so that it is in violation of the New York City Air Pollution Control Code.

811.3 All other engine and turbine discharge opening termination requirements.

The location of the discharge outlet from all other engines and turbines shall comply with the termination requirements of Section 801.21, Item 2 or Section 801.21, Item 3 based on the temperature of the flue gas entering the exhaust system.

811.4 Chimneys.

The exhaust system may be connected to a chimney used for other appliances, provided that the chimney complies with Section 811.1, Item 1 or Section 811.1, Item 2 and the operation of the engine does not adversely affect the operation of the other appliances and is in accordance with the New York City Air Pollution Control Code.