Fans are widely used to move air in a range of industries, including the cement industry. However, if not suitably insulated they can give rise to noise issues and impact the wellbeing of cement plant staff and local residents. In this article, Halifax Fan looks at noise levels from fans and how to reduce their impact. By Dr John Irons, Halifax Fan, UK, and Jessie Jia, Halifax Fan, China.
Sound is fluctuating air pressure created by a device. The sound pressure is the effect of the device, what is heard and measured. Sound power is the strength of the device, how much energy it is putting in to the air. Although the sound pressure depends on how close the person is to the sound source, the sound power is always the same. The sound power is related to the sound pressure by the area of an imaginary box around the sound source at the measurement distance:
Sound power = sound pressure x area
