Air-conditioning apparatus

An air-conditioning apparatus comprising:

• a heat source unit configured to generate a heating energy or a cooling energy and transfer the heating energy or the cooling energy to refrigerant;
• a heat-use unit configured to cause the refrigerant to transfer the heating energy or the cooling energy transferred from the heat source unit to a heat load through heat exchange between the refrigerant and the heat load;
• a supply pipe connecting the heat source unit and the heat-use unit to allow the refrigerant to flow from the heat source unit to the heat-use unit;
• a plurality of return pipes arranged parallel to each other, the return pipes connecting the heat source unit and the heat-use unit to allow the refrigerant to flow therein from the heat-use unit to the heat source unit;
• an opening and closing device provided at at least one of the return pipes, and configured to control a flow rate of refrigerant that passes through the return pipe;
• and
• a controller configured to open the opening and closing device in a cooling operation, and close the opening and closing device in a heating operation.