Use of sound intensity for determination of air-moving device noise emission

American National Standards on sound power determination via sound intensity and on measurement of noise from air-moving devices are at an advanced stage of development. The latter proposed standard requires a special test facility such as a reverberation room or a hemi-anechoic room, and does not permit the use of sound intensity for determination of noise emission. In this paper, the results of sound power determinations on air-moving devices in a reverberation room, a hemi-anechoic room, and in an ordinary laboratory environment are presented. The data in the ordinary room were obtained using sound intensity methods. The accuracy of the data in all three environments is discussed. Many of the “field indicators” which are recommended in the proposed sound intensity standard have been calculated in order to determine acceptable ranges for these indicators. The results indicate that determination of air-moving device sound power in ordinary rooms is adequate for many engineering purposes. Use of sound intensity for determination of air-moving device sound power should increase the amount of data available on these sources.