Abstract: According to one embodiment, an air conditioner includes an indoor unit, an outdoor unit, and a controller. The controller includes a first defrost module and a second defrost module. The first defrost module is configured to defrost a first outdoor heat exchanger and a second outdoor heat exchanger at the same time. The second defrost module is configured to start defrosting of the second outdoor heat exchanger in advance, and to perform defrosting of the first outdoor heat exchanger after the start of defrosting of the second outdoor heat exchanger.

Abstract: An air conditioner of an embodiment includes a plurality of outdoor units, one or more indoor units, and a control unit. The outdoor unit includes a compressor, a four-way valve, an outdoor heat exchanger, an outdoor expansion valve and an outdoor blower, and the outdoor units exchange heat between the outside air and a refrigerant. The indoor unit is an indoor unit connected to the plurality of outdoor units by a refrigerant pipe, includes an indoor heat exchanger, an indoor expansion valve, and an indoor blower, and exchanges heat between the indoor air and the refrigerant. The control unit controls the plurality of outdoor units and the one or more indoor units. The control unit controls the condensation pressure of the outdoor unit in a heating operation or the suction pressure of the outdoor unit in a defrosting operation to be equal to or smaller than an upper limit pressure, which is 1/1.

Abstract: According to one embodiment, an air conditioner carries out a heating operation, a cooling operation, a cooling/heating mixed operation in which a higher priority is given to cooling, and a cooling/heating mixed operation in which a higher priority is given to heating.