Refrigerant leakage detection system

A refrigerant leakage detection system for a refrigeration cycle device having a refrigerant circuit, the refrigerant leakage detection system comprising:

• a first controller that uses a first method to determine a presence or absence of refrigerant leakage from the refrigerant circuit;
• and
• a second controller that uses a second method different from the first method to determine the presence or absence of refrigerant leakage from the refrigerant circuit, wherein
• the refrigerant leakage detection system determines that there is a refrigerant leakage in the refrigerant circuit if the first controller determines that there is a refrigerant leakage from the refrigerant circuit and the second controller determines that there is a refrigerant leakage from the refrigerant circuit,
• the first controller determines the presence or absence of refrigerant leakage on the basis of an operational state of the refrigeration cycle device during a first period, and
• the second controller determines the presence or absence of refrigerant leakage on the basis of an operational state of the refrigeration cycle device during a second period that is longer than the first period.