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 dehumidification system for a heat pump, a method of operating a heat pump system, and a method of operating a refrigeration system are provided. The method of operating a heat pump system includes circulating refrigerant in a refrigerant circuit having a compressor (12), selectively communicating refrigerant from the compressor to an indoor heat exchanger (18) during a heating mode or to an outdoor heat exchanger (16) during a cooling mode or a reheat mode, selectively communicating refrigerant to a reheat heat exchanger during the reheat mode, and regulating a refrigerant volume in the reheat heat exchanger.

Various embodiments of a heat pump system are disclosed to provide improved and flexible heat pump operation when dehumidification of the conditioned space is required. In one embodiment, a heat pump system includes a heat pump loop comprising a refrigerant circuit that fluidly interconnects (1) a compressor; (2) a source heat exchanger; (3) a source heat exchanger bypass circuit comprising a bypass valve; (4) a space heat exchanger; (5) a reversing valve positioned on the discharge side of the compressor; (6) a reheat circuit comprising a reheat heat exchanger; (7) first and second expansion devices; and (8) first and second expansion device bypass circuits configured to allow refrigerant to bypass the first and second expansion devices, respectively, where the first and second bypass circuits include first and second check valves, respectively; and (9) a 3-way valve configured to selectively direct refrigerant flow to the first expansion device, the reheat circuit, and the second expansion device.

An air conditioner may include a case through which outdoor air flows into an indoor space is formed; a first heat exchanger that exchanges heat between the air and refrigerant; a second heat exchanger disposed downstream of the first heat exchanger, through which the refrigerant selectively flows, and that exchanges heat between the air and the refrigerant; a liquid pipe connected to each of the first and second heat exchangers; a high-pressure gas pipe connected to each of the first and second heat exchangers; a low-pressure gas pipe through which the gaseous refrigerant discharged from the first and second heat exchangers flows; a high-pressure gas pipe valve; a low-pressure gas pipe valve; an expansion valve installed in the liquid pipe; and a controller configured to control an opening degree of the low-pressure gas pipe valve, based on a temperature of the refrigerant flowing through the first heat exchanger.

A Variable Refrigerant Flow (VRF) dehumidification system. The system has at least one condenser module in fluid communication with one or more indoor air handlers. At least one evaporator coil is in fluid communication with the indoor air handlers and at least one reheat/reclaim coil. The evaporator and reheat/reclaim coils are also in communication with the condenser module. A plurality of electronic expansion valves (EEVs) are in fluid communication with the indoor air handlers. A plurality of sensors is disposed in the system and are in communication with at least one VRF dehumidification system controller. In one embodiment, a logic is stored in a non-transitory computer readable medium that, when executed by one or more processors, causes the VRF dehumidification system to monitor the data input from the plurality of sensors and regulates the capacity of the VRF dehumidification system needed to maintain a set dew point parameter.

A dehumidification system for a heat pump, a method of operating a heat pump system, and a method of operating a refrigeration system are provided. The method of operating a heat pump system includes circulating refrigerant in a refrigerant circuit having a compressor (12), selectively communicating refrigerant from the compressor to an indoor heat exchanger (18) during a heating mode or to an outdoor heat exchanger (16) during a cooling mode or a reheat mode, selectively communicating refrigerant to a reheat heat exchanger during the reheat mode, and regulating a refrigerant volume in the reheat heat exchanger.

Various embodiments of a heat pump system are disclosed to provide improved and flexible heat pump operation when dehumidification of the conditioned space is required. In one embodiment, a heat pump system includes a heat pump loop comprising a refrigerant circuit that fluidly interconnects (1) a compressor; (2) a source heat exchanger; (3) a source heat exchanger bypass circuit comprising a bypass valve; (4) a space heat exchanger; (5) a reversing valve positioned on the discharge side of the compressor; (6) a reheat circuit comprising a reheat heat exchanger; (7) first and second expansion devices; and (8) first and second expansion device bypass circuits configured to allow refrigerant to bypass the first and second expansion devices, respectively, where the first and second bypass circuits include first and second check valves, respectively; and (9) a 3-way valve configured to selectively direct refrigerant flow to the first expansion device, the reheat circuit, and the second expansion device.

The disclosed technology includes systems and methods for controlling an air conditioning system. The method of controlling the air conditioning system can include receiving air temperature data from an air temperature sensor and determining that the air conditioning system should operate in a reheat mode based on the air temperature being less than a threshold air temperature. The method can include outputting a control signal to a first electronic expansion valve to close and thereby prevent refrigerant to flow through an outdoor condenser coil. The method can also include outputting a control signal to a second electronic expansion valve to open and thereby permit refrigerant to flow through a reheat coil.

An air conditioner may include a case through which outdoor air flows into an indoor space is formed; a first heat exchanger that exchanges heat between the air and refrigerant; a second heat exchanger disposed downstream of the first heat exchanger, through which the refrigerant selectively flows, and that exchanges heat between the air and the refrigerant; a liquid pipe connected to each of the first and second heat exchangers; a high-pressure gas pipe connected to each of the first and second heat exchangers; a low-pressure gas pipe through which the gaseous refrigerant discharged from the first and second heat exchangers flows; a high-pressure gas pipe valve; a low-pressure gas pipe valve; an expansion valve installed in the liquid pipe; and a controller configured to control an opening degree of the low-pressure gas pipe valve, based on a temperature of the refrigerant flowing through the first heat exchanger.

A Variable Refrigerant Flow (VRF) dehumidification system. The system has at least one condenser module in fluid communication with one or more indoor air handlers. At least one evaporator coil is in fluid communication with the indoor air handlers and at least one reheat/reclaim coil. The evaporator and reheat/reclaim coils are also in communication with the condenser module. A plurality of electronic expansion valves (EEVs) are in fluid communication with the indoor air handlers. A plurality of sensors is disposed in the system and are in communication with at least one VRF dehumidification system controller. In one embodiment, a logic is stored in a non-transitory computer readable medium that, when executed by one or more processors, causes the VRF dehumidification system to monitor the data input from the plurality of sensors and regulates the capacity of the VRF dehumidification system needed to maintain a set dew point parameter.