Heat pump with dehumidification

A heat pump system for conditioning air in a space, comprising:

• a heat pump loop comprising a refrigerant circuit that fluidly interconnects:
• a variable speed compressor having a discharge outlet port and an inlet suction port;
• a refrigerant-to-liquid source heat exchanger operable as either a condenser or an evaporator for exchanging heat with a source liquid;
• a source heat exchanger bypass circuit comprising a bi-directional bypass valve to modulate refrigerant flow through the source heat exchanger;
• a refrigerant-to-air space heat exchanger operable as either an evaporator or a condenser for cooling or heating the air in the space;
• a reversing valve positioned on the discharge side of the compressor and configured to alternately direct refrigerant flow from the discharge outlet port of the compressor to one of the source heat exchanger and the space heat exchanger and to alternately return flow from the other of the source heat exchanger and the space heat exchanger to the suction inlet port of the compressor;
• a reheat circuit comprising a reheat heat exchanger to reheat the air when the system is in a dehumidification mode, and operable to act as an auxiliary condenser when the system is in a heating mode, wherein the space heat exchanger and the reheat heat exchanger are positioned in an air flow path for conditioning the air in the space;
• first and second electronic bi-directional expansion devices;
• first and second expansion device bypass circuits configured to allow refrigerant to bypass the first and second expansion devices, respectively, the first and second bypass circuits comprising first and second check valves, respectively, to control a direction of refrigerant flow in the first and second bypass circuits;
• and
• a 3-way valve configured to selectively direct refrigerant flow (i) to the first expansion device from the reheat circuit, (ii) to the reheat circuit from the first expansion device bypass circuit, and (iii) to the second expansion device from the first expansion device bypass circuit,
• wherein the first expansion device is positioned between the source heat exchanger and the 3-way valve, the second expansion device is positioned between the reheat circuit and the space heat exchanger, and the reheat circuit includes a bi-directional reheat bypass valve that loins an upstream leg and a downstream leg of the reheat heat exchanger and is positioned between the second expansion device and the 3-way valve to modulate refrigerant flow through the reheat heat exchanger.