This invention provides an air-conditioner that continues a heating operation while performing a
defrosting operation. A first bypass circuit 6 is provided for connecting the portion of a heat-pump-type refrigerating cycle between an indoor
heat exchanger 3 and a decompressor 4 to the suction side of a compressor 1. The first
bypass valve 6 is provided with a two-way valve 7 and a
refrigerant heater 8. Further, a second bypass circuit 9 is provided for connecting the portion between a four-way valve 2 and the indoor
heat exchanger 3 to the portion between the decompressor 4 and an outdoor
heat exchanger 5. The second bypass circuit 9 is provided with a
defrosting two-way valve 10. To defrost the outdoor heat exchanger 5, the decompressor 4 and the
defrosting two-way valve 10 are closed according to
outside air temperature and a fan 19 is rotated to perform a first defrosting operation. When the temperature detected by the temperature means of the outdoor heat exchanger is less than a predetermined value while the first defrosting operation is within a preset period of time, the two-way valve of the second bypass circuit is opened and an outdoor fan is stopped to perform a second defrosting operation.