When variable frequency refrigerator B was in food compartment door opening test at ambient
temperature of 15 C, compressor would respond to increase cooling/freezing capability to stop
temperature from rising. At the same time, damper opening between freezer and food compartment
was increased to allow more cold air to get into food compartment and compensate the
increased thermal load. In this case, freezer temperature would rise a little bit. Such responsive
measures caused food compartment to maintain almost constant temperature, as shown in Fig. 3.
However, to respond to temperature control, energy consumption would increase. It was found
that variable frequency refrigerator B increased energy consumption by 10.23% in food compartment door opening test. The average temperature in food compartment of fixed frequency
HRF without any control increased by around 2.5 C in door opening test and energy consumption
went up by 5.26%.