Comparison of the Sound Quality Characteristics for the Outdoor Unit according to the Compressor Model.

As for the criteria to purchase an air conditioner, noise level has emerged as an important issue, equal to design characteristics and performance. The main feature of the noise of the outdoor unit is a complex characteristic noise due to the operation of the fan and compressor. Air-borne noise is usually caused by the vortex separation on the fan blade, and structure-borne noise is caused by compressor or vibration transmission to the chassis and components. Due to the efforts of researchers and designers who have worked on noise reduction, the sound pressure level (SPL) of outdoor units launched on the market is under 50dB (A). While the SPLs of the noises are similar, consumers can feel the noise differently according to the frequency characteristics. Therefore in this study, it was purposed to evaluate sound quality by a comparative analysis of the noise characteristics, and tests were performed on the same outdoor unit only changing the compressors. To analyze the noise characteristics of the outdoor unit of the airconditioner, sound quality metrics such as Unbiased Annoyance (UA) and Psychoacoustic Annoyance (PA) were applied.