Combination Sound and Vibration Isolation Curb for Rooftop Air-Handling Systems

摘要

This paper discusses the new Model ESSR Sound and Vibration Isolation Curb manufactured byKinetics Noise Control, Inc. This product was specially designed to address all of the commontransmission paths associated with noise and vibration sources from roof-mounted air-handlingequipment. These include: reduction of airborne fan noise in supply and return air ductwork,reduction of duct rumble and breakout noise, reduction of direct airborne sound transmissionthrough the roof-deck, and reduction of vibration and structure-borne noise transmission to thebuilding structure. Upgrade options are available for increased seismic restraint and wind-loadprotection. The advantages of this new system over the conventional approach of installingseparate duct silencers in the room ceiling space below the rooftop unit are discussed. Some casestudies are presented with the emphasis on completed projects pertaining to classrooms andschool auditorium applications. Some success has also been achieved by adding active noisecontrol components to improve low-frequency attenuation. This is an innovative productdesigned for conformance with the new classroom acoustics standard ANSI S12.60.