An HVAC system is disclosed, comprising: (a) a compressor, (b) a source heat exchanger for exchanging heat with a source fluid, (c) a first load heat exchanger operable for heating/cooling air in a space, (d) a second load heat exchanger for heating water, (e) first and second reversing valves, (f) first and second 3-way valves, (f) a bi-directional electronic expansion valve, (g) a first bi-directional valve, and (h) a second bi-directional valve to modulate exchange of heat in the first load heat exchanger when operating as an evaporator and to control flashing of the refrigerant entering the source heat exchanger when operating as an evaporator, (h) a source pump for circulating the source fluid through the first load heat exchanger, (i) a water pump for circulating water through the second load heat exchanger, and (j) a controller to control operation of the foregoing.

The refrigeration cycle apparatus includes a refrigerant circuit, a controller to control the refrigerant circuit, a bypass flow path, and a flow control valve. The bypass flow path communicates between the discharge side of the compressor and the first outdoor heat exchanger or between the discharge side of the compressor and the second outdoor heat exchanger. The flow control valve is provided to the bypass flow path. The refrigerant circuit is configured to be able to perform a heating defrosting simultaneous operation. The heating defrosting simultaneous operation is an operation of supplying part of the refrigerant discharged from the compressor to one of the first outdoor heat exchanger and the second outdoor heat exchanger via the bypass flow path, causing the other of the first outdoor heat exchanger and the second outdoor heat exchanger to serve as an evaporator, and causing the indoor heat exchanger to serve as a condenser.

An air conditioning apparatus includes a heat exchange device that connects an outdoor unit to an indoor unit and that includes a heat exchanger configured to perform heat exchange between refrigerant and water. The heat exchanger reduces an amount of refrigerant used to perform a cooling operation or a heating operation.

An air conditioning apparatus includes a heat exchange device that connects an outdoor unit to an indoor unit and that includes a heat exchanger configured to perform heat exchange between refrigerant and water. The heat exchanger reduces an amount of refrigerant used to perform a cooling operation or a heating operation.

Embodiments include heat pump systems with gas bypasses and related methods. In one embodiment, a system may include a gas bypass tank having a bypass inlet, a liquid outlet, and a vapor outlet, and a first splitting valve having a first splitter outlet in fluid communication with the bypass inlet, a first splitter inlet in fluid communication with the liquid outlet, and a first switching path configured to switch between a first conduit path in fluid communication with a first coil system and a second conduit path in fluid communication with a second coil system.

Embodiments include heat pump systems with gas bypasses and related methods. In one embodiment, a system may include a gas bypass tank having a bypass inlet, a liquid outlet, and a vapor outlet, and a first splitting valve having a first splitter outlet in fluid communication with the bypass inlet, a first splitter inlet in fluid communication with the liquid outlet, and a first switching path configured to switch between a first conduit path in fluid communication with a first coil system and a second conduit path in fluid communication with a second coil system.

A heat pump is provided that includes a first pipe in which a first refrigerant flows; a second pipe disposed at a side of the first pipe and in which a second refrigerant flows; a first heat exchanger connected with the first pipe and the second pipe and in which the first refrigerant exchanges heat with the second refrigerant; a boiler connected with the first pipe and in which the first refrigerant flows; a compressor connected with the second pipe and that compresses the second refrigerant; a second heat exchanger connected with the second pipe and in which the second refrigerant exchanges heat with outdoor air; a bypass pipe branched from first pipe and configured to exchange heat with the second heat exchanger; and a three-way valve that directs the first refrigerant to pass through the bypass pipe. When the outdoor heat exchanger operates as an evaporator, frost formation thereon may be prevented.

A heat pump is provided that includes a first pipe in which a first refrigerant flows; a second pipe disposed at a side of the first pipe and in which a second refrigerant flows; a first heat exchanger connected with the first pipe and the second pipe and in which the first refrigerant exchanges heat with the second refrigerant; a boiler connected with the first pipe and in which the first refrigerant flows; a compressor connected with the second pipe and that compresses the second refrigerant; a second heat exchanger connected with the second pipe and in which the second refrigerant exchanges heat with outdoor air; a bypass pipe branched from first pipe and configured to exchange heat with the second heat exchanger; and a three-way valve that directs the first refrigerant to pass through the bypass pipe. When the outdoor heat exchanger operates as an evaporator, frost formation thereon may be prevented.

A refrigeration cycle apparatus includes a first three-way valve Each of the first three-way valve and the second three-way valve is configured to be switched independently to one of a first state In the first state, a first space is arranged in the valve chamber, the first space communicating with the first aperture and the second aperture and being separated from the third aperture. In the second state, a second space is arranged in the valve chamber, the second space communicating with the first aperture, the second aperture, and the third aperture. In the third state, a third space is arranged in the valve chamber, the third space communicating with the first aperture and the third aperture and being separated from the second aperture.

An air conditioner and a method for controlling an air conditioner. The method may include detecting an outlet temperature of a compressor; detecting a change in temperature of a hot water supply pipe; determining a system error based on the outlet temperature of the compressor; and determining an abnormality in an adjustment valve based on the temperature of the hot water supply pipe when a system error is determined.