| 摘要 |
PROBLEM TO BE SOLVED: To improve comfortability by reducing sound produced upon switching of a four-way valve at defrosting operation and shortening interruption time. SOLUTION: When upon heating operation a frosting judgment part 11 judges that frost is deposited on an outdoor heat exchanger 3, first interruption time is set to be longer and shorter by a first interruption time set part 12 based upon the magnitude of a temperature difference between temperature of an indoor heat exchanger 5 and that of the outdoor heat exchanger 3. Whilst during the first interruption time since the frosting judgment part 11 judges that frost is deposited on the outdoor heat exchanger 3, a first compressor interruption instruction part 13 issues an interruption instruction to interrupt the compressor 1. Thereafter, a four-way valve 2 is changed over to a dotted switching position to start defrosting operation. |
