Thermal storage device for climate control system

A heat pump comprising:

• a compressor, a metering device, a first heat exchanger, and a second heat exchanger;
• a refrigerant circuit comprising a refrigerant fluid that circulates between the first heat exchanger and the second heat exchanger;
• a first fan configured to produce an airflow, the first fan positioned adjacent the first heat exchanger;
• a second fan configured to produce an airflow, the second fan positioned adjacent the second heat exchanger;
• a thermal storage device coupled to the refrigerant circuit such that the refrigerant fluid flows therethrough in series with the first and the second heat exchanger, the thermal storage device configured to store thermal energy when the refrigerant fluid flowing therethrough is above a threshold temperature and discharge thermal energy when the refrigerant fluid flowing therethrough is below the threshold temperature;
• and
• control circuitry, wherein the control circuitry is configured to:
• operate the heat pump in a plurality of modes, the plurality of modes comprising a heating mode and a defrost mode,
• wherein in the heating mode the compressor circulates the refrigerant fluid such that heat is transferred from the refrigerant fluid at the first heat exchanger and heat is transferred to the refrigerant fluid at the second heat exchanger, and the temperature of the refrigerant fluid at the thermal storage device is above the threshold temperature such that heat from the refrigerant fluid is stored in the thermal storage device;
• wherein in the defrost mode the compressor circulates the refrigerant fluid such that heat is transferred to the refrigerant fluid at the first heat exchanger and heat is transferred from the refrigerant fluid at the second heat exchanger, and the temperature of the refrigerant fluid at the thermal storage device is below the threshold temperature such that heat from the thermal storage device is discharged to the refrigerant fluid,
• wherein in both heating mode and defrost mode the refrigerant fluid flows through the thermal storage device, the first heat exchanger, and the second heat exchanger.