502.16 Repair garages for natural gas- and hydrogen-fueled vehicles.

Repair garages used for the repair of natural gas- or hydrogen-fueled vehicles shall be provided with an approved mechanical ventilation system. The mechanical ventilation system shall be in accordance with Sections 502.16.1 and 502.16.2.

   Exception: Where approved by the commissioner, natural ventilation shall be permitted in lieu of mechanical ventilation.

502.16.1 Design.

Indoor locations shall be ventilated utilizing air supply inlets and exhaust outlets arranged to provide uniform air movement to the extent practical. Inlets shall be uniformly arranged on exterior walls near floor level. Outlets shall be located at the high point of the room in exterior walls or the roof.

   1.   Ventilation shall be by a continuous mechanical ventilation system or by a mechanical ventilation system activated by a continuously monitoring natural gas detection system, or for hydrogen, a continuously monitoring flammable gas detection system, each activating at a gas concentration of 25 percent of the lower flammable limit (LFL). In all cases, the system shall shut down the fueling system in the event of failure of the ventilation system.

   2.   The ventilation rate shall be not less than 1 cubic foot per minute per 12 cubic feet (0.00138 m 3 /(s • m 3 )) of room volume.

502.16.2 Operation.

The mechanical ventilation system shall operate continuously.

   Exceptions:

      1.   Mechanical ventilation systems that are interlocked with a gas detection system designed in accordance with the New York City Building Code.

      2.   Mechanical ventilation systems in garages that are used only for the repair of vehicles fueled by liquid fuels or odorized gases, such as CNG, where the ventilation system is electrically interlocked with the lighting circuit.

502.17 Tire rebuilding or recapping.

Each room where rubber cement is used or mixed, or where flammable or combustible solvents are applied, shall be ventilated in accordance with the applicable provisions of NFPA 91.

502.17.1 Buffing machines.

Each buffing machine shall be connected to a dust-collecting system that prevents the accumulation of the dust produced by the buffing process.