Experimental study on new type of defrosting system using outdoor air for frost-free household refrigerators

Air-cooled frost-free household refrigerators have become popular in the market because of their large storage volume and frost-free compartments. However, the large amount of power consumed by the defrosting process of the evaporator restricts the widespread application of such refrigerators. In this study, a new type of defrosting system using outdoor air (DSUOA) is developed. The operation modes (refrigeration and defrosting cycles) of the overall system are proposed. An experimental prototype is built, and an experimental study is conducted for different temperature ranges (12-22 °C, 22-45 °C, and 0-12 °C). Results show that the power consumption of DSUOA is 77.6-98.2% less than that of the electric heater defrosting system under a similar defrosting time.