Air conditioning system

An air conditioning system being configured to switch between indoor heating and cooling, the air conditioning system comprising:

• a compressor being configured to compress a refrigerant to critical pressure or greater;
• a first heat source-side heat exchanger being configured to heat or to cool the refrigerant;
• a second heat source-side heat exchanger being configured to exchange heat between the refrigerant and a heat delivery medium;
• a first utilization-side heat exchanger being configured to perform indoor cooling by using the refrigerant cooled in the first heat source-side heat exchanger;
• a second utilization-side heat exchanger being configured to perform indoor heating by using the heat delivery medium subjected to heat exchange in the second heat source-side heat exchanger;
• and
• a connection mechanism being configured to switch between a first connection state in which the refrigerant discharged from the compressor is circulated sequentially through the first heat source-side heat exchanger, the first utilization-side heat exchanger, and the compressor, and a second connection state in which the refrigerant discharged from the compressor is circulated sequentially through the second heat source-side heat exchanger, the first heat source-side heat exchanger, and the compressor,
• the compressor, the first heat source-side heat exchanger, the second heat source-side heat exchanger, and the connection mechanism constituting a heat source unit,
• the first utilization-side heat exchanger constituting a utilization unit, and
• the utilization unit and heat source unit being connected via refrigerant communication pipes.