An air conditioning system and a control method are provided. The air conditioning system includes: at least one heat exchanger (1, 2); and at least one control mechanism. Each control mechanism is connected to one of the at least one heat exchanger (1, 2) and is configured to control the corresponding heat exchanger to switch between a first working state and a second working state. The heat exchanger (1, 2) drains liquid when in the first working state and stores liquid when in the second working state.

A charge-verification tool is used with a charge-verification system to diagnose and remedy a charge condition. The charge-verification tool includes a device having a controller configured to communicate with a system controller in the charge-verification system and a display configured to display measurements and instructions to an installer. The device is a user interface and is configured to provide communication between the installer and the system controller in the charge-verification system. The controller prompts the installer to input charge-verification system information including refrigeration line length and diameter. The controller receives a subcooling temperature calculated by the system controller and determines whether the subcooling temperature is between a threshold and a target subcooling temperature. The controller displays an amount of charge to add to the charge-verification system based on whether the subcooling temperature is between the threshold and the target subcooling temperature.

A refrigeration cycle apparatus is provided with a refrigerant circuit, a refrigerant tank circuit, and a degassing pipe. The refrigerant circuit is configured by connecting a compressor, a flow path switching apparatus, a first heat exchanger, a decompressing apparatus, and a second heat exchanger. The refrigerant tank circuit is connected to the first and second heat exchangers in parallel with the decompressing apparatus. The degassing pipe has a first end and a second end. The flow path switching apparatus is configured to switch a flow of refrigerant discharged from the compressor to any of the first and second heat exchangers. The refrigerant tank circuit contains a refrigerant tank. The degassing pipe has the first end connected to the refrigerant tank and has the second end connected to at least any of the refrigerant circuit and the refrigerant tank circuit.

An air conditioner including a refrigerant circuit including a compressor, an outdoor heat exchanger, an outdoor expansion valve, an indoor expansion valve, and an indoor heat exchanger. The refrigerant circuit including an auxiliary heat exchanger provided on a refrigerant pipe between the outdoor heat exchanger and the indoor expansion valve and connected in series with the outdoor expansion valve, and a rectifier configured to allow a refrigerant flowing from the outdoor heat exchanger toward the indoor expansion valve in a cooling operation or a refrigerant flowing from the indoor expansion valve toward the outdoor heat exchanger in a heating operation to sequentially flow through the auxiliary heat exchanger and the outdoor expansion valve.

A refrigeration cycle apparatus includes a refrigerant circuit that includes a condenser, multiple temperature sensors that are disposed in line in a direction in which refrigerant flows in the condenser and detect refrigerant temperature of the condenser, a memory unit that stores positional information of the multiple temperature sensors, and a refrigerant amount calculation unit that calculates a refrigerant amount of the condenser based on the positional information of the multiple temperature sensors, detected temperatures of the multiple temperature sensors and a saturated liquid temperature of the refrigerant.

During a first cooling operation, a compressor is in an operational state, a liquid pump is in a non-operational state, and an amount of refrigerant allowing for existence of a liquid surface of the refrigerant in a refrigerant tank is accumulated in the refrigerant tank. During a second cooling operation, the compressor is in the non-operational state, the liquid pump is in the operational state, and the amount of the refrigerant allowing for the liquid surface of the refrigerant in the refrigerant tank is accumulated in the refrigerant tank.

A method for determining system subcooling in a vapor compression system including a compressor, a condenser, an expansion device and an evaporator operatively connected in a serial relationship in a refrigerant flow circuit, the method including receiving information indicative of a compressor torque or compressor current; and determining a degree of system subcooling in response to the receiving of the information.

An air conditioning system that includes at least one indoor unit that uses water as a working fluid, an outdoor unit that uses a refrigerant as a working fluid, the outdoor unit including a compressor compressing the refrigerant and an outdoor heat exchanger for heat-exchange with the refrigerant, and a heat collection unit connecting the at least one indoor unit to the outdoor unit, the heat collection unit including at least one heat exchange part for heat-exchanging water supplied from the at least one indoor unit with the refrigerant supplied from the outdoor unit.

A refrigeration cycle apparatus is provided with a compressor, a condenser, a pressure-reducing device, and an evaporator. The refrigeration cycle apparatus comprises a refrigeration cycle configured to circulate refrigerant; and a control unit configured to control the refrigeration cycle. The control unit causes the refrigeration cycle to operate when an operation condition is satisfied, the operation condition including elapse of a preset time after the control unit stops the refrigeration cycle. The control unit detects abnormality of the refrigeration cycle based on state data indicating a state of the refrigeration cycle after the control unit causes the refrigeration cycle to operate.

Provided is a air conditioner including high-and-low-pressure gas pipe expansion valves each of which is provided to a corresponding one of the cooling-heating switching units and adjusts feeding of high-temperature and high-pressure gas refrigerant to the corresponding indoor unit; and a refrigeration cycle controller which adjusts a valve opening degree of the high-and-low-pressure gas pipe expansion valve of the cooling-heating switching unit connected to one of the indoor units which is not in heating operation, in accordance with a determination result on excess or deficiency of refrigerant in a refrigeration cycle.