An indoor unit for heating, cooling, and dehumidifying air is disclosed. In an embodiment, the indoor unit includes a first coil assembly and a second coil assembly. When operating in a cooling mode or a heating mode, the first coil and second coil are in parallel fluid communication. When in a dehumidifying mode, the first coil and second coil are in serial fluid communication, which enables the first coil to function as a condenser and the second coil to function as an evaporator. The disclosed indoor unit provides negligible or no change in sensible heat while providing dehumidification.

Provided is a multi-type air conditioner, including: an outdoor unit having a liquid pipe through which a liquid refrigerant flows, and a gas pipe through which a gas refrigerant flows; a plurality of indoor units comprising a first indoor unit and a second indoor unit each connected to the liquid pipe and the gas pipe to circulate a refrigerant; a gas pipe connecting tube connecting the gas pipe and the plurality of indoor units so that a gas refrigerant flows therethrough; and a liquid pipe connecting tube connecting the liquid pipe and the plurality of indoor units so that a liquid refrigerant flows therethrough. The first indoor unit may include: a first indoor heat exchanger comprising a first heat exchanger configured to perform heat exchange between indoor air and a refrigerant, and a second heat exchanger configured to perform heat exchange between indoor air and a refrigerant and arranged in a stacked fashion with the first heat exchanger; a first indoor fan configured to blow air to the first heat exchanger and the second heat exchanger; a first liquid branch pipe connecting the liquid pipe connecting tube and the first heat exchanger so that a refrigerant flows therethrough; a first gas branch pipe connecting the gas pipe connecting tube and the second heat exchanger so that a refrigerant flows therethrough; a first heat exchanger connecting pipe connected to the first heat exchanger so that a refrigerant flows therethrough; a second heat exchanger connecting pipe connected to the second heat exchanger so that a refrigerant flows therethrough; a return pipe having one side connected to the first gas branch pipe and the other side connected to the first heat exchanger connecting pipe and the second heat exchanger connecting pipe; a first indoor expansion valve disposed at the second heat exchanger connecting pipe, wherein an opening amount of the first indoor expansion valve is adjusted in response to an input signal from a controller to selectively expand a flowing refrigerant; and a first expansion valve disposed in the return pipe, wherein an opening amount of the first expansion valve is adjusted in response to an input signal from the controller to selectively expand a flowing refrigerant.

Since the multi-type air conditioner according to the present disclosure can operate the first heat exchanger as a condenser and the second heat exchanger as an evaporator among the indoor heat exchangers, it is possible to constantly operate the dehumidifying mode while maintaining a room temperature within a predetermined range.

A heat pump system includes a refrigerant circuit that has a compressor, a first heat exchanger, a second heat exchanger, a reheat heat exchanger, a modulating valve, and a reversing valve. The reversing valve is configured to transition between a first configuration to direct refrigerant from the compressor toward the modulating valve and a second configuration to direct the refrigerant from the compressor toward the first heat exchanger. The heat pump system also includes control circuitry configured to concurrently maintain the reversing valve in the first configuration and adjust a position of the modulating valve to direct a first portion of the refrigerant from the modulating valve to the second heat exchanger and a second portion of the refrigerant from the modulating valve to the reheat heat exchanger based on an operating mode of the heat pump system.

An air conditioner unit includes a compressor, an exterior coil, a main interior coil, a main expansion device, a reheat interior coil and a reheat expansion device. The reheat interior coil is positioned adjacent the main interior coil. The main expansion device is connected in series between the exterior coil and the main interior coil, and the reheat expansion device is connected in series between the main expansion device and the reheat interior coil. A reheat valve is operable to selectively adjust a flow direction through the reheat interior coil. The reheat valve is a four-way valve, and one port of the four-way valve is blocked.

A system and related methods for heating, cooling, and dehumidifying air is disclosed. In an embodiment, the system includes an indoor unit having a first coil assembly and a second coil assembly. When the system is operating in a cooling mode or a heating mode, the first coil and second coil are in parallel fluid communication. When the system is in a dehumidifying mode, the first coil and second coil are in serial fluid communication, which enables the first coil to function as a condenser and the second coil to function as an evaporator. In an embodiment, the system includes an outdoor unit, such as a heat pump or an air conditioning condensing unit. The outdoor unit includes a heat exchanger fan responsive to dehumidifying mode by reducing fan speed, or deactivating the fan entirely. The disclosed system provides negligible or no change in sensible heat while providing dehumidification.

A thermal management system includes a refrigerant system, which includes a compressor, a flow control device, a valve member, a first heat exchanger, a second heat exchanger, and a third heat exchanger. The flow control device includes a first throttle unit, a second throttle unit, and a valve assembly; the flow control device includes a first port, a second port, and a third port; a first connection port of the first heat exchanger is in communication with the second port, and a first connection port of the second heat exchanger is in communication with the third port, while a first connection port of the third heat exchanger is in communication with the first port. The thermal management system includes a first operating state and a second operating state.

An air conditioner includes an outdoor unit including a compressor, first and second indoor heat exchangers to receive a refrigerant from the outdoor unit, the second indoor heat exchanger receiving the refrigerant independently of the first indoor heat exchanger, and a fan disposed between the first and second indoor heat exchangers. First and second refrigerant pipes form flow paths between the outdoor unit and the first and second indoor heat exchangers. First and second expansion valves are disposed on the first and second refrigerant pipes. Third and fourth refrigerant pipes form flow paths between the compressor and the first and second indoor heat exchangers. A first opening and closing valve selectively opens and closes a fifth refrigerant pipe to selectively allow refrigerant to flow between the second and third refrigerant pipes. Second and third opening and closing valves selectively open and close the second and third refrigerant pipes.

An air conditioner unit includes a compressor, an exterior coil, a main interior coil, a main expansion device, a reheat interior coil and a reheat expansion device. The reheat interior coil is positioned adjacent the main interior coil. The main expansion device is connected in series between the exterior coil and the main interior coil, and the reheat expansion device is connected in series between the main expansion device and the reheat interior coil. A reheat valve is operable to selectively adjust a flow direction through the reheat interior coil. The reheat valve is a four-way valve, and one port of the four-way valve is blocked.

An air-conditioner is provided with a refrigerant circuit and an indoor fan. The refrigerant circuit has a compressor, a first four-way valve, an outdoor heat exchanger, a first expansion valve, a second four-way valve, a third four-way valve, an indoor heat exchanger, and a second expansion valve. The indoor heat exchanger has a first heat exchange portion and a second heat exchange portion. During a cooling operation, in the first heat exchange portion and the second heat exchange portion, a flow of refrigerant with respect to a flow of air sent by the indoor fan is a parallel flow. In a reheating dehumidification operation, in the first heat exchange portion, the flow of refrigerant with respect to the flow of air is the parallel flow, and in the second heat exchange portion, the flow of refrigerant with respect to the flow of air is a counterflow.

An air conditioner has a refrigerant circuit and a blower. A refrigerant flow path switching mechanism is configured to switch to a first switching state to allow refrigerant to flow through a reheater, a second expansion valve, and a cooler in this order in a refrigerant circuit. The refrigerant flow path switching mechanism is configured to switch to a second switching state to allow refrigerant to flow through the reheater, the second expansion valve, and the cooler in this order in the refrigerant circuit. The reheater and the cooler are configured to allow air blown by the blower to pass through the cooler and then pass through the reheater during either of the first switching state and the second switching state.