Acoustic Characterization of Retrofit Vertical Duct Soundproof Enclosure for Portable Mini-Generators

Abstract

Environmental noise pollution from electric power generators has become seemingly intractable in most developing countries due to the epileptic power supply. Families as well as corporate organizations now rely on these standby generators for their daily electricity needs. The concern of this paper was the characterization of the developed vertical duct soundproof acoustic enclosure on mitigating the noise produced by portable mini generators. A total of six acoustic parallelepiped boxes were produced using chopped strand E-glass fiber mat reinforced composite panels with polyurethane foam inner lining. The generator noise spectra with and without the enclosure were obtained for comparative analysis. The sound pressure level of the generator noise at each enclosure height was also measured. It was found out that the noise level reduced by 12.8 dBA when the sound pressure levels at both conditions were taken and compared at optimal enclosure height (1600 mm). The result from exhaust ducting showed that exhaust duct projection, channeling out the fumes, did not significantly impact the enclosure insertion loss. The enclosure and the generator were also found to be in stable, acceptable thermal conditions while operating at rated load with a maximum temperature of 39 °C measured inside the enclosure. This eliminates the need for artificial cooling and its consequent power drain.