Air conditioner

An air conditioner comprising a refrigerant circuit including an outdoor unit and an indoor unit that are connected together and a controller that controls operation of the refrigerant circuit, and a non-azeotropic refrigerant mixture containing a hydrofluorocarbon having a property of undergoing a disproportionation reaction being sealed in the refrigerant circuit;

• wherein the controller executes pump down operation in which substantially all of the non-azeotropic refrigerant mixture that is unevenly distributed throughout the refrigerant circuit is collected into a portion of the refrigerant circuit within the outdoor unit,
• after the completion of the pump down operation, executes compositional ratio determination in which a compositional ratio of the non-azeotropic refrigerant mixture is determined based on a pressure and temperature of the non-azeotropic refrigerant mixture collected into the outdoor unit by the pump down operation, and
• generates an alert when the compositional ratio of the non-azeotropic refrigerant mixture determined by the compositional ratio determination is outside an acceptable proportion range of the hydrofluorocarbon having the property of undergoing a disproportionation reaction.