The commonly used recirculation air systems for microelectronics cleanrooms are described in this paper. The sound attenuation along the air flow paths are discussed along with noise control concerns. Also presented are the typical sound pressure levels measured in operating cleanrooms.
Mei Q. Wu and Colin G. Gordon, "Noise of Cleanroom Recirculation Air Systems," (with Mei Wu), Proceedings of the 16th International Congress on Acoustics, Seattle, WA, pp. 769-770, June 1998.