Section 928 Noise Control Requirements

Interior and exterior mechanical equipment and systems shall comply with the provisions of this section.

Mechanical equipment located outside of the building in a yard or court or on a roof, or located inside a building but open to the exterior of the building, shall comply with the requirements of Sections 928.2.1 and 928.2.2.

The applicant shall select and design any such exterior mechanical equipment in order to achieve compliance with the applicable requirements of Sections 24-218, 24-227, 24-228 and 24-232 of the Administrative Code, also known as the New York City Noise Control Code, in accordance with generally acceptable engineering practices.

The operation of such exterior mechanical equipment shall comply with any applicable requirements of Sections 24-218, 24-227, 24-228 and 24-232 of the New York City Noise Control Code, as enforced by the Department of Environmental Protection.

All isolators shall comply with the requirements of Sections 928.3.1 through Section 928.3.10.

Equipment piping shall be installed as follows:

1. Metal piping connected to power driven equipment shall be resiliently supported from or on the building structure for a distance of 50 pipe diameters from the power driven equipment. The resilient isolators shall have a minimum static deflection of 1 inch (25 mm) for all piping with a 4 inch (102 mm) or larger in actual outside diameter and ¹/₂ inch (12.7 mm) for piping with less than 4 inches (102 mm) in actual outside diameter. Piping connected to fluid pressure-reducing valves shall be resiliently isolated for a distance of 50 pipe diameters from pressure-reducing valves and isolators shall provide a minimum static deflection of ¹/₂ inch (12.7 mm).
2. Equipment such as heat exchangers, absorption refrigeration machines, or similar equipment, that is located on any floor or roof other than a floor on grade, and that is not power driven but is connected by metal piping to power driven equipment, shall be resiliently supported from or on the building structure, for a distance of 50 pipe diameters from the power driven equipment. The resilient supports shall be vibration isolators having a minimum static deflection of 1 inch (25 mm) and shall incorporate approved resilient pads having a minimum thickness of ¹/₄ inch (6.4 mm).

All fan equipment with motors in excess of ¹/₂ horsepower (0.37 kW), located on any roof or floor other than a floor on grade shall be mounted on or from vibration isolators. Fan equipment with motor drives separated from the fan equipment shall be supported on an isolated integral rigid structural base supporting both the fan and motor. Fan equipment with motor drives supported from the fan equipment shall be mounted directly on vibration isolators. Each isolator shall have provision for leveling. Isolators shall incorporate resilient pads having a minimum thickness of ¹/₄ inch (6.4 mm). The vibration isolators shall provide a minimum isolation efficiency of 90 percent at fan rotor rpm with a maximum deflection of 2 inches (51 mm). Fans and compressors assembled in unitary containers may meet this requirement with isolators internal to the container providing the isolators meet the above minimum isolator efficiencies.

All pumps of 3 horsepower (2.25 kW) or more located on any floor other than a floor on grade shall be supported on vibration isolators having a minimum isolation efficiency of 90 percent at the lowest disturbing frequency. Each isolator shall incorporate a leveling device and a resilient pad having a minimum thickness of ¹/₄ inch (6.4 mm).

Compressors and drives located on a floor other than a floor on grade shall be mounted on vibration isolators having a minimum isolation efficiency of 90 percent at the lowest disturbing frequency. Each isolator shall incorporate a leveling device and a resilient pad having a minimum thickness of ¹/₄ inch (6.4 mm).

All moving parts of cooling towers located on a roof or floor other than a floor on grade shall be installed on vibration isolators providing a minimum isolation efficiency of 90 percent at fan rotor rpm with a maximum static deflection of 4 inches (102 mm). Each isolator shall incorporate a leveling device and a resilient pad having a minimum thickness of ¹/₄ inch (6.4 mm). Vibration cutoff switches shall be provided.

Evaporative and air cooled condensers located on a roof or floor other than a floor on grade shall be mounted on vibration isolators providing a minimum isolation efficiency of 90 percent at fan rotor rpm with a maximum static deflection of 4 inches (102 mm). Each isolator shall incorporate a leveling device and a resilient pad having a minimum thickness of ¹/₄ inch (6.4 mm). Vibration cutoff switches shall be provided on evaporative condensers.

Flexible connections shall be installed between fan equipment and connecting ductwork.

Equipment such as heat pumps, AC units, or similar equipment, that is suspended from a structure shall be resiliently supported from or on the building structure. Vibration isolators shall have a minimum isolation efficiency of 90 percent at the lowest disturbing frequency.