The present disclosure provides an air conditioner system and a control method for the same. The air conditioner system includes: a refrigeration system. A first port of a second four-way valve is connected to a pipeline between the first four-way valve and the indoor heat exchanger, and a second port of a second four-way valve is connected to a first position in a pipeline between the indoor heat exchanger and the outdoor heat exchanger. A first port of the first passage of an auxiliary heat exchanger is in communication with a fourth port of the second four-way valve, and a second port of the first passage is connected to a second position in a pipeline between the indoor heat exchanger and the outdoor heat exchanger.

An energy efficient heat pump for a heating, ventilation, and air conditioning (HVAC) system includes a vapor compression circuit, a heat exchanger of the vapor compression circuit configured to place a working fluid in a heat exchange relationship with an air flow directed across the heat exchanger, and a valve system of the vapor compression circuit. The valve system is adjustable between a first configuration and a second configuration, the heat pump is configured to operate in a cooling mode with the valve system in the first configuration and in a heating mode with the valve system in the second configuration, and the valve system is configured to direct the working fluid into the heat exchanger to place the working fluid in a counterflow heat transfer arrangement with the air flow in the first configuration and in the second configuration.

A heat exchanger group includes a first heat exchanger, a second heat exchanger, and a third heat exchanger. In a cooling operation, refrigerant discharged from the compressor is divided into two. One refrigerant is delivered to the second heat exchanger, and the other refrigerant is delivered to the third heat exchanger. The second heat exchanger performs heat exchange to turn the refrigerant into two-phase refrigerant. The third heat exchanger performs heat exchange to turn the refrigerant into two-phase refrigerant. The refrigerant that has flowed through the second heat exchanger and the refrigerant that has flowed through the third heat exchanger meet, and the resultant refrigerant is delivered to the first heat exchanger. The first heat exchanger performs heat exchange, so that the two-phase refrigerant turns into liquid refrigerant and flows through the first heat exchanger.

A heat-medium flow-path switching device and a heat-medium flow-rate adjusting device are integrated into an integrated heat-medium flow-rate adjusting device. The integrated heat-medium flow-rate adjusting device is configured to perform the heat-medium flow-path switching function and the meat-medium flow-rate adjusting function by driving and controlling a single drive unit. Moreover, the integrated heat-medium flow-path switching device is configured to perform a function of closing flow paths from/to a use-side heat exchanger added to the heat-medium flow-rate adjusting function.

A controller performs medium pressure control that controls the opening degree of a second expansion device based on a deviation between a target value of medium pressure, and a detection result of a medium pressure detector or a predicted value. The controller controls the opening degree of a third expansion device based on a target value of a discharge refrigerant temperature of a compressor or a target value related to the discharge refrigerant temperature, and a detection result of a discharge refrigerant temperature detector or a value related to the discharge refrigerant temperature computed using a detected detection result, and regulates a flow rate of refrigerant to supply to a suction side of the compressor via an injection pipe.

An air conditioner 1 of the embodiment of the present invention, when all compressors 21a-21c have been stopping for a given time or more, starts an air conditioning operation without performing pressure equalizing control in switch units 6a-6d with starting the operation of the air conditioner 1. Also, when the stopping time of all compressors 21a-21c is less than the given time, the air conditioner 1 performs the pressure equalizing control by controlling switch units 6a-6d with starting the operation of the air conditioner 1. In this case, when the stopping time reaches the given time during execution of the pressure equalizing processing control, the pressure equalizing processing control being executed is stopped and the air conditioning operation is started.

An energy efficient heat pump for a heating, ventilation, and air conditioning (HVAC) system includes a vapor compression circuit, a first heat exchanger of the vapor compression circuit configured to place a working fluid in a first heat exchange relationship with a first air flow directed across the first heat exchanger, a second heat exchanger of the vapor compression circuit configured to place the working fluid in a second heat exchange relationship with a second air flow directed across the second heat exchanger, and a valve system of the vapor compression circuit. The valve system is adjustable between a first configuration and a second configuration, the heat pump is configured to operate in a cooling mode with the valve system in the first configuration, the heat pump is configured to operate in a heating mode with the valve system in the second configuration, and the valve system is configured to direct the working fluid into the first heat exchanger to place the working fluid in a counterflow heat transfer arrangement with the first air flow directed across the first heat exchanger in the first configuration and in the second configuration.

An air-conditioning apparatus includes actuation control means including an actuation unit that sequentially opens heat medium flow switching devices or heat medium flow control devices on a one-by-one basis. The actuation control means performs control in such a manner that start time of driving of pumps is later than start of actuation of the heat medium flow switching devices and the heat medium flow control devices.

An air-conditioning apparatus includes a main circuit in which a compressor, an indoor heat exchanger, a first flow control device, and a plurality of parallel heat exchangers connected in parallel to each other are sequentially connected via a pipe to allow refrigerant to circulate, a first defrost pipe that branches a part of the refrigerant discharged from the compressor and allows the refrigerant to flow into the parallel heat exchanger to be defrosted among the plurality of parallel heat exchangers, a expansion device provided in the first defrost pipe and configured to depressurize the refrigerant discharged from the compressor, and a connection switching device that allows the refrigerant flowing out of the parallel heat exchanger to be defrosted to flow into the main circuit at a position upstream of the parallel heat exchangers other than the parallel heat exchanger subject to defrosting.

An air-conditioning apparatus includes a plurality of indoor units each located inside a building and at a position that enables the indoor unit to condition air, and a relay unit installed in a space not to be air-conditioned inside the building. The relay unit and each indoor unit are connected to each other via a first heat medium pipe in which a first heat medium such as water or brine flows. The relay unit accommodates therein a first refrigerant circuit including a compressor, a plurality of first intermediate heat exchangers that exchange heat between the first heat medium and refrigerant that performs a phase shift or turns to a supercritical state during operation, a plurality of expansion devices, and a second intermediate heat exchanger that exchanges heat between the refrigerant and a second heat medium, which are connected via a refrigerant pipe.