Michael Gendreau

This paper is concerned with noise conditions in cleanrooms served by fan-filter units (FFUs), primarily of higher order clean class (ISO Class 1 through 5), although the concepts discussed also apply to rooms with higher particle counts (ISO Class 6 and higher). The need for frequent air changes to achieve the cleanliness goal is often the source of elevated noise levels from the HVAC systems. On the other hand, cleanrooms are often used in research and manufacturing environments that contain noise sensitive personnel and equipment. This paper illustrates typical design challenges in cleanrooms served by FFUs, either in the form of room boundary fan elements or “mini-environments” attached directly to sensitive the process and research equipment. FFU noise data formats, typical spectra, and noise mitigation options are discussed.

 

Reprinted from Proceedings of the 11th International Congress on Sound and Vibration St. Petersburg, Russia, 5-8 July 2004