Sound Quality Improvement of Refrigerator using the Analysis of High Frequency Noise Radiated from Compressor in the Machine Room

This paper provides an analysis of the characteristics of the noise of components that affect the sound quality of oil-less refrigerators and suggests ways to effectively improve the sound quality. As the sound quality of refrigerators is determined by the characteristics of the various components and the path through which the noise is transferred, it is necessary to first analyze the characteristics of the noise generated by the components. Therefore, after measuring the noise of each part, we conducted a contribution analysis of the sound quality of each noise source. As a result, the oil-less compressor was found to be the dominant part of the sound quality of the refrigerator, while the high-frequency noise of the compressor is the main cause of poor sound quality. Then, to improve the sound quality by reducing the high-frequency noise of the compressor, we changed the transfer path of the noise using sound-absorbing and -insulating material and predicted the effect of the sound quality through a pressure transmissibility test. As a result of verification from actual operation, the sound quality of the refrigerator was improved most by the reduction of the sharpness and criteria of declination when the absorbent was attached to the surrounding walls of the compressor. Finally, the overall SPL decreased by 2.95 dBA, and the sound quality score was improved by 1.83.