Acoustics
Supply/return and exhaust ductwork shall not have an internal lining for either noise attenuation or insulation. Air transfers (neutral temp air) may be lined for acoustical considerations.
Whenever possible, select low sound level fans and route/size ductwork so that duct silencers/sound attenuators are not required to meet project sound requirements. Where sound requirements cannot be satisfied without the addition of duct silencers/attenuators, the maximum pressure drop of the system silencer/attenuator shall not exceed 0.15” WC and the unit shall include a mylar/tedlar cover so that the attenuating material is not in direct contact with the air stream. Attenuators are typically not required at all terminal unit locations.
Refer to Acoustical Section - Volume 3, Chapter 2.7
Systems shall be designed to provide sound levels (NC) no greater than listed:
| Classrooms | 35 (30 Recommended) |
| Private Office Areas | 35 |
| Open Office Areas | 40 |
| Common Areas | 40 |
| Performing Arts | 25 |
| Assembly Space/Conference | 30 |
| Library/Media Center | 35 |
| Athletic Spaces | 45 |
Refer to Room Data Sheets for specific requirements for each space.
Vibration Isolation
Vibration isolation: Required for all mechanical piping, ductwork and equipment. This is crucial to reduce or eliminate the transfer of noise and stress throughout the building systems. All vibration controls for mechanical elements shall meet CPS Specification Section 23 05 48.
Piping: The use of spring, elastomeric or spring plus elastomeric hangers shall be provided for all pipe runs. Refer to Specifications for locations/types/spacing. At connection to equipment with motors/fans/compressors/burners, the use of flexible pipe connection shall be provided.
Ductwork: The use of spring, elastomeric or spring plus elastomeric hangers shall be provided for ductwork. Refer to Specifications for locations/types/spacing. Flexible duct connection shall be provided at the connection to and from equipment with motors/fans/compressors/burners to prevent vibration transfer to the ductwork system.
Equipment: All HVAC equipment with motors/fans/compressors/burners, including pumps, fans, chillers, condensing units and cooling towers, shall have proper bases and isolators to comply with Specifications.