Refrigeration apparatus with defrost during heating operation

A refrigeration apparatus comprising:

• a refrigerant circuit including a compressor, an outdoor heat exchanger, an expansion mechanism, and an indoor heat exchanger connected to each other, the refrigerant circuit being capable of executing at least a heating operation by circulating a refrigerant through the refrigerant circuit;
• and
• a controller configured to start a defrosting operation for melting frost formed on the outdoor heat exchanger when a first defrosting start condition is satisfied in a case where a predetermined premise situation is not established and start the defrosting operation when a second defrosting start condition stricter than the first defrosting start condition is satisfied in a case where the predetermined premise situation is established, wherein
• the predetermined premise situation is satisfied in at least any of the following cases:
• a case where an elapsed time from a last stop of the compressor is equal to or longer than a predetermined elapsed time at a start of the heating operation;
• a case where a time of day at the start of the heating operation satisfies a predetermined time of day condition;
• a case where a temperature of the outdoor heat exchanger or a refrigerant pipe connected to the outdoor heat exchanger is equal to or higher than a predetermined temperature at the start of the heating operation;
• a case where a difference between a set temperature and an indoor temperature is equal to or larger than a predetermined value at the start of the heating operation;
• and
• a case where a state of the refrigerant in the refrigerant circuit satisfies a predetermined refrigerant state or the difference between the set temperature and the indoor temperature is equal to or larger than a predetermined value after an elapse of a predetermined period from the start of the heating operation.