| 摘要 |
PROBLEM TO BE SOLVED: To prevent a base for placing an outdoor heat exchanger from being frozen in case of heating operation at low fresh air temperature. SOLUTION: An air conditioner is adapted such that there are coupled in order a compressor 1, a four-way valve 2, an outdoor heat exchanger 3, a pressure reducing device 4, and an indoor heat exchanger 5 to form a refrigerant circuit, and heat transfer pipes of the outdoor heat exchangers 3 are disposed longitudinally in two lines. In the air conditioner, upper and lower two coupling parts which couple upper ends and lower ends of the front row and the back row of the heat transfer pipes are taken as middle parts 3a, 3b of the outdoor heat exchanger 3, and parallel bypass circuits including opening/closing valves 6a, 6b are provided between the two middle parts 3a, 3b and a discharge side of the compressor 1. upon cooling and heating operations both opening/closing valves 6a, 6b are closed, and upon defrosting operation both opening/closing valves are opened whereby part of refrigerant gas discharged from the compressor 1 is supplied to the two middle parts 3a, (3b. Further, upon heating operation where fresh air temperature is lower than predetermined temperature the opening/closing valve 6a is closed while the opening/closing valve 6b is opened to supply the part of the refrigerant gas discharged from the compressor 1 to the middle part 3b. |
