ABSTRACT
This chapter is devoted to control of the acoustical noise emitted by the types of air-moving devices (AMDs) commonly used in electronic cabinets to satisfy a given cooling requirement —expressed in terms of volumetric flow rate in cubic meters per second or liters/sec at a given static pressure in newtons per square meter. It begins with a review of noise terminology and facilities for noise measurement in the form of a glossary of topics on noise. The chapter contains information on experimental determination of the sound power level of AMDs using standardized techniques. It describes methods for measurement of sound intensity and its relationship to sound pressure level. The sound power level, both A-weighted and in octave or one third octave bands, has been found to be a useful descriptor for the noise emitted by fans and blowers because it is much less dependent on the environment in which the source is placed than is sound pressure level.
