A flow path switch is provided with a first opening to a fourth opening. A discharge side of a compressor is connected to the first opening. A first end of a first heat exchange unit is connected to the fourth opening. A first end of the second inner flow path is connected to the second opening. A first branching portion is connected to a first end of the second valve and the third opening. When an operation mode of an air conditioning apparatus is a first mode, the second valve is open, the first opening is connected to the fourth opening, and the second opening is connected to the third opening. When the operation mode of the air conditioning apparatus is a second mode, the second valve is closed, the first opening is connected to the third opening, and the second opening is connected to the fourth opening.

A flow path switch is provided with a first opening to a fourth opening. A discharge side of a compressor is connected to the first opening. A first end of a first heat exchange unit is connected to the fourth opening. A first end of the second inner flow path is connected to the second opening. A first branching portion is connected to a first end of the second valve and the third opening. When an operation mode of an air conditioning apparatus is a first mode, the second valve is open, the first opening is connected to the fourth opening, and the second opening is connected to the third opening. When the operation mode of the air conditioning apparatus is a second mode, the second valve is closed, the first opening is connected to the third opening, and the second opening is connected to the fourth opening.

A HVAC system having an indoor heat exchanger having a first refrigerant passage extending in a first direction and a second refrigerant extending in a second direction opposite from the first direction, a first refrigerant circuit comprising a first compressor, a first expansion valve, a first outdoor heat exchanger, the first refrigerant passage, and a first reversing valve operable to control a direction of first refrigerant in the first refrigerant circuit, and a second refrigerant circuit comprising a second compressor, a second expansion valve, a second outdoor heat exchanger, the second refrigerant passage, and a second reversing valve operable to control a direction of second refrigerant in the second refrigerant circuit.

A HVAC system having an indoor heat exchanger having a first refrigerant passage extending in a first direction and a second refrigerant extending in a second direction opposite from the first direction, a first refrigerant circuit comprising a first compressor, a first expansion valve, a first outdoor heat exchanger, the first refrigerant passage, and a first reversing valve operable to control a direction of first refrigerant in the first refrigerant circuit, and a second refrigerant circuit comprising a second compressor, a second expansion valve, a second outdoor heat exchanger, the second refrigerant passage, and a second reversing valve operable to control a direction of second refrigerant in the second refrigerant circuit.

A heat pump system includes a refrigerant circuit comprising a compressor, a reversing valve, a first heat exchanger, a second heat exchanger, a reheat heat exchanger, and a three-way valve. The reversing valve is configured to receive refrigerant from the compressor and adjust between a first configuration to direct the refrigerant toward the three-way valve and a second configuration to direct the refrigerant toward the first heat exchanger. The three-way valve is configured to adjust between a first position to direct the refrigerant between the reversing valve and the second heat exchanger and a second position to direct the refrigerant from the reversing valve to the reheat heat exchanger.

A heat pump system includes a refrigerant circuit comprising a compressor, a reversing valve, a first heat exchanger, a second heat exchanger, a reheat heat exchanger, and a three-way valve. The reversing valve is configured to receive refrigerant from the compressor and adjust between a first configuration to direct the refrigerant toward the three-way valve and a second configuration to direct the refrigerant toward the first heat exchanger. The three-way valve is configured to adjust between a first position to direct the refrigerant between the reversing valve and the second heat exchanger and a second position to direct the refrigerant from the reversing valve to the reheat heat exchanger.

In a refrigeration cycle apparatus, refrigerant circulates in order of a compressor, first and second heat exchangers. The refrigeration cycle apparatus has a refrigerant container, first and second switch units, and a controller. When a first condition meaning that an amount of refrigerant in liquid state stored in the refrigerant container is excessive is satisfied, the controller controls the first switch unit to guide the refrigerant from the compressor to the first heat exchanger through the refrigerant container and controls the second switch unit to guide the refrigerant from the second heat exchanger to the compressor not through the refrigerant container. When the first condition is not satisfied, the controller controls the first switch unit to guide the refrigerant from the compressor to the first heat exchanger not through the refrigerant container and controls the second switch unit to guide the refrigerant from the refrigerant container to the compressor.

An air-conditioning apparatus includes: a heat source-side system having an intermediate heat exchanger that causes heat exchange to be performed between a heat source-side heat medium and a use-side heat medium, causes the heat source-side heat medium to receive or transfer heat, and causes the use-side heat medium to undergo a phase change; and a use-side cycle circuit formed of pipes connecting, to one another, the intermediate heat exchanger, a pump that sucks and delivers the use-side heat medium in a liquid state, a use-side heat exchanger that heats or cools air in an air-conditioning target space due to heat exchange causing a change in phase of the use-side heat medium, and a pressure-reducing device that reduces a pressure of the use-side heat medium that passes through the use-side heat exchanger, the use-side cycle circuit causing the use-side heat medium to circulate through the use-side cycle circuit.

An air-conditioning apparatus includes: a heat source-side system having an intermediate heat exchanger that causes heat exchange to be performed between a heat source-side heat medium and a use-side heat medium, causes the heat source-side heat medium to receive or transfer heat, and causes the use-side heat medium to undergo a phase change; and a use-side cycle circuit formed of pipes connecting, to one another, the intermediate heat exchanger, a pump that sucks and delivers the use-side heat medium in a liquid state, a use-side heat exchanger that heats or cools air in an air-conditioning target space due to heat exchange causing a change in phase of the use-side heat medium, and a pressure-reducing device that reduces a pressure of the use-side heat medium that passes through the use-side heat exchanger, the use-side cycle circuit causing the use-side heat medium to circulate through the use-side cycle circuit.

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.