In a refrigeration cycle apparatus according to the present invention, a non-azeotropic refrigerant mixture is used. The refrigeration cycle apparatus includes a compressor, a first heat exchanger, a decompressor, a second heat exchanger, a third heat exchanger, and a blower. The blower blows air to the second heat exchanger and the third heat exchanger. The non-azeotropic refrigerant mixture circulates in a first circulation direction through the compressor, the first heat exchanger, the decompressor, the second heat exchanger, and the third heat exchanger. The second heat exchanger is greater in flow path resistance than the third heat exchanger. The blower forms a parallel flow with the non-azeotropic refrigerant mixture that flows through the second heat exchanger and the third heat exchanger.

An air conditioning system includes an air conditioning apparatus, and a controller. The air conditioning apparatus performs air conditioning of an air-conditioning target space. The controller is connectable to a plurality of types of thermostats. The controller performs communication with the thermostat connected thereto. The controller performs a performance determination process for the refrigeration cycle apparatus. The controller performs different performance determination processes according to whether a first type of thermostat is connected thereto unit or whether a second type of thermostat is connected thereto. Alternatively, the air conditioning apparatus changes a method for using information received by the controller from the thermostat according to whether being in a determination processing time over which the performance determination process is performed or in a non-determination processing time over which the performance determination process is not performed.

An air-conditioning apparatus includes: a plurality of heat source units each including a compressor, a heat-source-side heat exchanger, a flow control valve, and an accumulator; a use-side load connected to the heat source units by pipes, and including a use-side heat exchanger that causes heat exchange to be performed between refrigerant supplied from each of the heat source units and a use-side heat medium; and a controller that controls an operation of each of the heat source units. The controller includes a determination unit and a liquid equalization unit. The determination unit determines whether or not a current operation is a non-normal operation in which the heat source units and the use-side load operate in a different manner from that in a heating operation or a cooling operation. The liquid equalization unit equalizes the amounts of liquid refrigerant that flows in the heat source units, when the determination unit determines that the current operation is the non-normal operation.

A method of operating an air conditioner unit to implement effective defrost cycles includes obtaining a coil temperature of an outdoor heat exchanger, a dew point of a flow of air through the outdoor heat exchanger, and a flow rate of the flow of air. A frost rate of frost buildup on the outdoor heat exchanger is estimated based on the coil temperature, the dew point, and the flow rate, and a frost quantity or weight is determined by integrating the frost rate. A defrost cycle is initiated if the frost quantity exceeds a predetermined frost threshold, e.g., in pounds of water.

An apparatus evaluation system includes a first evaluation unit that evaluates a first air conditioning apparatus, and a first air conditioning control unit that controls a second air conditioning apparatus. The first evaluation unit performs a first evaluation process to evaluate the first air conditioning apparatus based on a first evaluation index obtained in a first operation performed as a first evaluation operation at a time of installation, and a second evaluation process to evaluate the first air conditioning apparatus based on the first evaluation index obtained in a second operation performed as the first evaluation operation after the first evaluation process. The control unit operates the second air conditioning apparatus before at least one of the first and second operations of the first air conditioning apparatus is performed, and/or while at least one of the first and second operations of the first air conditioning apparatus is being performed.

A performance degradation diagnosis system includes a determining unit, and control unit. A refrigeration cycle apparatus includes a refrigerant circuit having a compressor, heat-source-side heat exchanger, and use-side heat exchanger. The determining unit determines, based on an index indicating an operation state of the refrigeration cycle apparatus, performance degradation of the refrigeration cycle apparatus with respect to each of a plurality of performance degradation factors. In a case in which the determining unit determines performance degradation, the control unit grasps an operation condition of the refrigeration cycle apparatus which is operating. In a case in which the operation condition of the refrigeration cycle apparatus is not suitable to determine performance degradation with respect to a performance degradation factor of a determination target, the control unit controls the operation condition of the refrigeration cycle apparatus so that the operation condition of the refrigeration cycle apparatus becomes an appropriate operation condition.

A heat pump system including a charge compensator having a liquid line port for an inflow of a refrigerant into the charge compensator and for an outflow of the refrigerant from the charge compensator. The heat pump system further includes an isolation valve configured to control flows of the refrigerant to and from the charge compensator through a liquid line piping of the heat pump system based on whether the heat pump system is operating in a cooling mode, a defrost mode, or a heating mode, where the liquid line port is fluidly coupled to the liquid line piping of the heat pump system.

A heat pump may include a compressor configured to compress a refrigerant, a first temperature sensor configured to detect an outdoor temperature, a second temperature sensor provided in heating pipes connected to a heating device, and a controller. Based on a first sensing value of the first temperature sensor, the controller may be configured to control a compressor, control power to a boiler, and/or calculate an expected efficiency of the heat pump. Based on the expected efficiency and/or a second sensing value of a second temperature sensor, the controller may be configured to control power to the boiler.

A heat exchanger includes: a plurality of flat tubes; a fin in which a plurality of notches are arranged side by side in a vertical direction, the fin having a plurality of intermediate portions and a connecting portion connecting the intermediate portions to each other; and a first bulging portion having an upper end edge and a lower end edge provided between a first notch and a second notch, the upper end edge being positioned in the intermediate portion and the lower end edge being positioned in the connecting portion. The upper end edge has a first upper end positioned on an intermediate portion side, and a second upper end positioned on a connecting portion side, the first upper end being positioned to be higher than the second upper end, or the first upper end being positioned at the same height as the second upper end.

The invention provides a refrigeration apparatus configured to cool the interior of a casing of a heat source unit by a refrigerant. An air conditioner includes a heat source unit, a utilization unit having a utilization heat exchanger and constituting a refrigerant circuit along with the heat source unit, and a controller. The heat source unit causes heat exchange between a refrigerant and a heat source, and cools the interior of the casing, and causes a valve to switch to supply or not to supply the cooling heat exchanger with the refrigerant. The controller assesses, before the refrigerant is supplied to the cooling heat exchanger, whether or not the refrigerant flowing from the cooling heat exchanger toward the compressor comes into a wet state when the refrigerant is supplied, and determines whether or not to open the valve in accordance with an assessment result.