Performance comparison with effect of door opening on variable and fixed frequency refrigerators/freezers

This paper presents the effect of door openings of refrigerators/freezers on the energy consumption and compartment temperature variation by experimental approach. Two types of refrigerators/freezers were tested in the study. One is a type of variable frequency operation, while the other is a type of fixed frequency operation. The testing procedure was conducted under the ambient temperatures of 15 and 30 °C, and the door opening operation was carried out by one automatic robotic apparatus in an environmental control room. From the test results, energy consumption of refrigerators/freezers with door opening was found to increase by 10%, compared to the same product without door opening. Based on the compartment temperature variation status during door opening, control strategy was also proposed to improve the efficiency of variable frequency type of refrigerators/freezers. Future study on door opening control methodology can be addressed on usage's characteristics, so that it would help to control temperature variation and improve energy utilization by minimizing the effect of door opening.