Noise Generation in Household Refrigerators: An Experimental Study on fluid Borne Noise

The oscillatory pressure disturbance created by the refrigerant flow through pipes and components is one of the main sources of noise in household refrigerators. This type of excitation is transferred to the pipes and the vibratory energy travels through the structure reaching the cabinet from which it radiates as sound energy. In order to obtain a better understanding of this type of noise a household refrigerator was instrumented with thermocouples, absolute and acoustic pressure transducers and accelerometers. Tests were carried out under different operating conditions. It was observed that the compressor is the main source of excitation, affecting practically the entire refrigeration loop. It was also found that the acoustic excitation at the exit of the capillary tube is high enough to induce significant vibrations in the evaporator. In view of the database collected, comments and suggestions concerning the design of household refrigerators are presented and discussed.