Sub-cooling a refrigerant in an air conditioning system

An air conditioning system, comprising:

• at least one compressor configured to compress a refrigerant in a vapor phase;
• a condenser fluidly coupled to the at least one compressor to receive the compressed vapor phase of the refrigerant and configured to change the compressed vapor phase of the refrigerant to a liquid phase of the refrigerant by transferring heat from the compressed vapor phase of the refrigerant to a cooling fluid;
• an expansion device fluidly coupled to the condenser with a liquid line to receive the liquid phase of the refrigerant and configured to expand the liquid phase of the refrigerant from a first pressure to a second pressure lower than the first pressure;
• an evaporator fluidly coupled to the expansion device to receive the liquid phase of the refrigerant at the second pressure and configured to transfer heat from an airflow circulated through the evaporator to the liquid phase of the refrigerant at the second pressure to change at least a portion of the liquid phase of the refrigerant at the second pressure to the vapor phase of the refrigerant and change at least a portion of water vapor in the airflow into a liquid condensate;
• and
• a heat exchanger fluidly coupled to the liquid line to receive at least a portion of the liquid phase of the refrigerant from the condenser upstream of the expansion device, the heat exchanger at least partially immersed in the liquid condensate captured in a condensate receiver from the evaporator and configured to sub-cool the portion of the liquid phase of the refrigerant based on a transfer of heat from the portion of the liquid phase of the refrigerant to the liquid condensate.