Design and performance evaluation of a soundproof enclosure for a 2.5kVA generator

Abstract

The high level of noise that radiates from domestic generators in most parts of the neighbourhoods in Nigeria is becoming very much uncomfortable and constitutes nuisance to public serenity thereby creating noise pollution. This paper reports the design and performance evaluation of a soundproof enclosure for a 2.5 kVA generator. The purpose of this work was to reduce the sound pressure level (SPL) of the generator from a control value of 102 decibel to a comfortable noise level of about 86 decibel at a distance of 4 m. Material selection was done based on absorptivity, sound reduction coefficient of acoustic materials and the sizing of the absorber was done to determine the thickness required for lining the enclosure. Panel made of steel and sound absorbing material were used to control the noise propagation at its transmission path. Performance test of the soundproof device was carried out and SPL from the generator before and after the application of the enclosure were measured. This reveals a sound attenuation of 9.5, 12.9, 11.6, 12.2, 15.1, 14.5, and 15.5 dB at distances of 0.6, 1.2, 1.8, 2.4, 3.0, 3.6, 4.2 m respectively by using mineral wool with a noise reduction coefficient (NRC) of 0.78.

Keywords: Attenuation, Decibel, Absorber, Sound pressure level