Swimming Pool or Spa Heat Pump With Refrigerant Charge Compensator and Method of Operating Same

A method of operating a heat pump capable of operating in a cooling mode of operation and a heating mode of operation, comprising:

• increasing the pressure of refrigerant with a compressor to generate high-pressure, high-temperature refrigerant;
• causing the high-pressure, high-temperature refrigerant to flow through a first heat exchanger and transfer thermal energy to a first fluid;
• reducing the pressure and the temperature of the high-pressure, high-temperature refrigerant to generate low-pressure, low-temperature refrigerant;
• causing the low-pressure, low-temperature refrigerant to flow through a second heat exchanger and extract thermal energy from a second fluid, the second fluid being pool or spa water;
• causing the low-pressure, low-temperature refrigerant to flow through a refrigerant charge compensator after flowing through the second heat exchanger, the refrigerant charge compensator positioned between the second heat exchanger and a reversing valve;
• reducing an amount of active refrigerant charge in circulation in the heat pump with the refrigerant charge compensator;
• and
• returning the low-pressure, low-temperature refrigerant to the compressor.

A swimming pool or spa heat pump capable of operating in a cooling mode of operation and a heating mode of operation, comprising:

• a housing;
• a compressor;
• a first heat exchanger configured to transfer thermal energy to and extract thermal energy from ambient air, the first heat exchanger being a microchannel heat exchanger;
• a fan configured to blow ambient air across the first heat exchanger;
• a second heat exchanger configured to transfer thermal energy to and extract thermal energy from pool or spa water;
• a reversing valve fluidly coupled with the compressor, the first heat exchanger, and the second heat exchanger, the reversing valve being configured to receive pressurized refrigerant from the compressor, direct the pressurized refrigerant to the first heat exchanger when the heat pump is in the cooling mode of operation, and direct the pressurized refrigerant to the second heat exchanger when the heat pump is in the heating mode of operation;
• at least one means for lowering the pressure of refrigerant being provided to the first heat exchanger when the heat pump is operated in the heating mode of operation and lowering the pressure of refrigerant being provided to the second heat exchanger when the heat pump is operated in the cooling mode of operation;
• and
• a refrigerant charge compensator having a chamber in fluidic communication with a refrigerant line at a position between the first heat exchanger and the second heat exchanger, the refrigerant charge compensator being configured to (1) cause refrigerant to be removed from circulation and stored in the chamber to reduce an amount of active refrigerant charge in circulation in the heat pump when the heat pump is operated in the cooling mode of operation and (2) cause refrigerant stored in the chamber to reenter circulation to increase the amount of active refrigerant charge in circulation in the heat pump when the heat pump is operated in the heating mode of operation,
• wherein the first heat exchanger has a lower heat transfer flux than the second heat exchanger.