An air conditioner includes a compressor; an outdoor heat exchanger; an indoor heat exchanger; an outdoor fan configured to supply outdoor air to the outdoor heat exchanger; and an indoor fan configured to supply indoor air to the indoor heat exchanger. The air conditioner performs a heating operation by driving both the indoor fan and the outdoor fan and by causing refrigerant to flow in one direction through both the indoor heat exchanger and the outdoor heat exchanger and so that a defrost operation in which both the indoor fan and the outdoor fan are stopped is performed by causing the refrigerant to flow in the opposite direction to that in the heating operation. When a defrost failure is caused by the defrost operation the outdoor fan is driven, and the indoor fan is stopped for a predetermined period of time, after which the defrost operation is resumed.

An outdoor unit control unit 200 has a defrosting operation condition table 300a that defines an activation rotational speed Cr in accordance with a total sum of flow rate coefficients Cva that is a total sum of flow rate coefficients Cv representing capacities of indoor expansion valves 52a to 52c. The outdoor unit control unit 200 calculates the total sum of the flow rate coefficients Cva by adding the flow rate coefficient Cv of each of the indoor expansion valves 52a to 52c, and refers to the defrosting operation condition table 300a, so as to determine the activation rotational speed Cr. Then, the outdoor unit control unit 200 activates a compressor 21 at the determined activation rotational speed Cr when starting a defrosting operation, maintains this activation rotational speed Cr for a predetermined time from the start of the defrosting operation, and drives the compressor 21.

Provided is a refrigeration cycle apparatus including a refrigerant circuit configured to circulate refrigerant, a heat exchanger unit accommodating a heat exchanger of the refrigerant circuit, and a controller configured to control the heat exchanger unit, in which the heat exchanger unit includes an air-sending fan, and an electric refrigerant detection unit, the controller is configured to operate the air-sending fan when the controller detects leakage of the refrigerant on the basis of a detection signal from the electric refrigerant detection unit, and the controller is configured to stop electric supply to the electric refrigerant detection unit when a rotation speed of the air-sending fan becomes equal to or larger than a first threshold value under a state in which the electric refrigerant detection unit is supplied with electricity.

An air conditioner, having an outdoor unit and an indoor unit, to perform a heating operation and a defrosting operation, the air conditioner including a detection unit to detect a state of at least one selected between the outdoor unit and the indoor unit and to output the detected value, a controller to determine whether the air conditioner is in a stable state when the defrosting operation is completed and, upon determining that the air conditioner is in the stable state, to control the detected value output from the detection unit to determine entry time of the next defrosting operation, and a storage unit to store a value detected in the stable state. The entry time of the defrosting operation is accurately determined, thereby minimizing the number of times of the defrosting operation during the heating operation.

An air conditioning system is provided. The system has a high-pressure pipe, a low-pressure pipe, an indoor heat exchanger, an outdoor heat exchanger, a leak-free thermal expansion valve and a variable capacity compressor. The variable capacity compressor has a shell, a first cylinder and a second cylinder. The shell has a suction port and an exhaust port. The first cylinder has a first suction hole connected to the suction port and a first exhaust hole connected to the exhaust port. The second cylinder has a second suction hole connected to the suction port, a second exhaust hole connected to the exhaust port, and a pressure relief hole connected to the high-pressure pipe and the low-pressure pipe in an on-off manner. Before the variable capacity compressor is started, the high-pressure pipe and the low-pressure pipe are connected and also disconnected after the first preset duration.

Disclosed is a chiller including a pull-down procedure or pull-down mode, a sustain procedure or sustain mode and, additionally, a heat-up procedure or heat-up mode or temper mode. This allows the chiller to deliberately and determined heat up content if the starting temperature of the content is below the target temperature for serving the content.

Provided is a refrigeration cycle apparatus including: a refrigeration cycle configured to circulate refrigerant; a heat exchanger unit configured to accommodate at least a heat exchanger of the refrigeration cycle; and a controller configured to control the heat exchanger unit, in which: the heat exchanger unit includes: an air-blowing fan; and a refrigerant detection unit configured to detect a concentration of leaked refrigerant and to output a detection signal to the controller; and the controller is configured to operate the air-blowing fan when detecting leakage of the refrigerant, and to stop the air-blowing fan triggered by becoming positive from negative of a temporal change of the concentration of the leaked refrigerant.

A usage-side air-conditioning apparatus has: a casing; a usage-side heat exchanger to cool or heat air inside the casing through the use of a refrigerant supplied from a heat-source-side air-conditioning apparatus; an air supply/exhaust mechanism to take room air and/or outdoor air in from an air-conditioned space or outside of the air-conditioned space, supply the air as supply air to the air-conditioned space, and exhaust the air as exhaust air out of the air-conditioned space; and a refrigerant leakage detection device to detect the refrigerant. When the refrigerant leakage detection device has detected the refrigerant, a refrigerant exhaust operation is performed by the air supply/exhaust mechanism to exhaust the refrigerant out of the air-conditioned space along with the air inside the casing.

A refrigeration cycle apparatus includes a refrigerant circuit including a compressor, a condenser (outdoor heat exchanger), an expansion valve, and an evaporator (indoor heat exchanger), a fan configured to blow air to the condenser, a fan configured to blow air to the evaporator, and a controller configured to control at least one of a frequency of the compressor, an opening degree of the expansion valve, a rotation speed of the fan, and a rotation speed of the fan, such that the refrigerant sucked into the compressor has a quality of 1.0 or greater. The refrigerant circuit is configured for use with a refrigerant mixture inclusive of 30 wt % to 50% wt ethylene-based hydrofluorocarbon refrigerant.

A refrigeration cycle apparatus includes: a refrigeration cycle circuit including a compressor, a four-way valve, a heat source side heat exchanger, a heat source side pressure-reducing mechanism, an indoor side pressure-reducing mechanism, and an indoor side heat exchanger, and a hot water supply refrigerant circuit branching off from between the compressor and the four-way valve, including a hot water supply side heat exchanger and a hot water supply side pressure-reducing mechanism in order, and connected between the heat source side pressure-reducing mechanism and the indoor side pressure-reducing mechanism, wherein when a refrigerant state value on at least one of a low pressure side of the refrigeration cycle circuit and a discharge side of the compressor becomes a refrigerant collection start state value, a refrigerant collecting operation that collects refrigerant accumulated in the hot water supply refrigerant circuit into the refrigeration cycle circuit is started.