Abstract: An air-conditioner for performing a heating operation includes an indoor unit with an indoor heat exchanger set in an air-conditioning target space. There is an outdoor unit set outside the air-conditioning target space, the outdoor unit including a compressor, an outdoor heat exchanger, and an outdoor fan to supply outdoor air to the outdoor heat exchanger. Additionally, there is a humidifier to heat and evaporate condensed water in the outdoor unit to send the evaporated water into the indoor unit. The humidifier includes a water reservoir to store the condensed water in the outdoor unit, and a heating portion formed by a discharge pipe in which the refrigerant discharged from the compressor flows. The discharge pipe communicates between the compressor and the indoor heat exchanger in the heating operation, and the heating portion heats and evaporated the condensed water stored in the water reservoir with heat of the refrigerant.

Abstract: An air-conditioning apparatus includes a main circuit in which a compressor, a flow switching device, an indoor heat exchanger, a pressure reducing device, and a plurality of parallel heat exchangers connected in parallel with each other are connected by pipes, a bypass pipe, a flow control device provided to the bypass pipe and configured to adjust a flow rate of refrigerant flowing through the bypass pipe, an evaporating pressure sensor configured to measure an evaporating pressure of the refrigerant, and a controller. The air-conditioning apparatus is configured to operate in a normal heating operation mode and a heating-defrosting operation mode. When an operation associated with the normal heating operation mode is switched to an operation associated with the heating-defrosting operation mode, the controller adjusts an opening degree of the flow control device using the evaporating pressure in the parallel heat exchanger and a driving frequency of the compressor.

Abstract: Provided is an air-conditioning apparatus having a low-outside-air-temperature cooling operation mode including: a refrigerant circuit; an outdoor fan; an outdoor air temperature sensor; an indoor heat exchanger intermediate temperature sensor; an indoor heat exchanger outlet temperature sensor; and a controller configured to, when a measured value from the outdoor air temperature sensor is equal to or less than a predetermined value, perform the low-outside-air-temperature cooling operation mode, wherein in the low-outside-air-temperature cooling operation mode, the controller is configured to reduce a rotation speed of the outdoor fan, and to, when a difference between a measured value from the indoor heat exchanger outlet temperature sensor and a measured value from the indoor heat exchanger intermediate temperature sensor is equal to or greater than a first threshold, increase an opening degree of the pressure reducing device.

Abstract: An air-conditioning apparatus includes a controller configured to operate in a heating normal operation mode and a heating-defrosting operation mode. In a case of switching from the heating normal operation mode to the heating-defrosting operation mode, the controller makes a selection from an initial control mode 1, in which control is performed such that an initial frequency of the compressor is set to a predetermined maximum frequency and an initial opening degree of the flow control device is set to an opening degree lower than a predetermined maximum opening degree, and an initial control mode 2, in which control is performed such that the initial opening degree of the flow control device is set to the predetermined maximum opening degree and the initial frequency of the compressor is set to a frequency lower than the predetermined maximum frequency, to execute the heating-defrosting operation mode.

Abstract: An air-conditioning apparatus includes a compressor, an outdoor fan, and a controller configured to perform a fan intermittent operation for causing the outdoor fan to run and stop repeatedly after the compressor stops. The controller is configured to, in the fan intermittent operation, in a case where the outdoor fan is running and there is no snow accumulation on the outdoor fan, change a stop upper limit time for the outdoor fan depending on a running time of the outdoor fan in the fan intermittent operation and cause the outdoor fan to stop running after changing the stop upper limit time for the outdoor fan. The controller is configured to, in a case where a stop time of the outdoor fan exceeds the changed stop upper limit time, cause the outdoor fan to run.

Abstract: An air-conditioning apparatus includes a controller configured to operate in a heating normal operation mode and a heating-defrosting operation mode. In a case of switching from the heating normal operation mode to the heating-defrosting operation mode, the controller makes a selection from an initial control mode 1, in which control is performed such that an initial frequency of the compressor is set to a predetermined maximum frequency and an initial opening degree of the flow control device is set to an opening degree lower than a predetermined maximum opening degree, and an initial control mode 2, in which control is performed such that the initial opening degree of the flow control device is set to the predetermined maximum opening degree and the initial frequency of the compressor is set to a frequency lower than the predetermined maximum frequency, to execute the heating-defrosting operation mode.

Abstract: An air-conditioning apparatus includes a main circuit in which a compressor, a flow switching device, an indoor heat exchanger, a pressure reducing device, and a plurality of parallel heat exchangers connected in parallel with each other are connected by pipes, a bypass pipe, a flow control device provided to the bypass pipe and configured to adjust a flow rate of refrigerant flowing through the bypass pipe, an evaporating pressure sensor configured to measure an evaporating pressure of the refrigerant, and a controller. The air-conditioning apparatus is configured to operate in a normal heating operation mode and a heating-defrosting operation mode. When an operation associated with the normal heating operation mode is switched to an operation associated with the heating-defrosting operation mode, the controller adjusts an opening degree of the flow control device using the evaporating pressure in the parallel heat exchanger and a driving frequency of the compressor.

Abstract: An air-conditioning apparatus includes a main circuit in which a compressor, a load side heat exchanger, a first pressure reducing device, and a plurality of parallel heat exchangers connected in parallel with each other are connected by pipes, a bypass pipe diverting a portion of refrigerant discharged by the compressor, a flow switching unit connecting a parallel heat exchanger to be defrosted to the bypass pipe, a plurality of flow rate control devices controlling flow rates of refrigerant flowing through the plurality of parallel heat exchangers, and a controller which controls, in the heating-defrosting operation mode or in the heating operation mode after execution of the heating-defrosting operation mode, the flow rate control devices to control, in accordance with a frost state of a parallel heat exchanger functioning as an evaporator among the plurality of parallel heat exchangers, the flow rate of refrigerant flowing through the parallel heat exchanger.

Abstract: An air-conditioning apparatus includes a main circuit in which a compressor, a load side heat exchanger, a first pressure reducing device, and a plurality of parallel heat exchangers connected in parallel with each other are connected by pipes, a bypass pipe diverting a portion of refrigerant discharged by the compressor, a flow switching unit connecting a parallel heat exchanger to be defrosted to the bypass pipe, a plurality of flow rate control devices controlling flow rates of refrigerant flowing through the plurality of parallel heat exchangers, and a controller which controls, in the heating-defrosting operation mode or in the heating operation mode after execution of the heating-defrosting operation mode, the flow rate control devices to control, in accordance with a frost state of a parallel heat exchanger functioning as an evaporator among the plurality of parallel heat exchangers, the flow rate of refrigerant flowing through the parallel heat exchanger.