| 摘要 |
PURPOSE:To eliminate uncomfortable feeling due to the noise generated when stopping an operation, by operating an exterior-side blower prior to switching a four-way valve, when stopping a defrosting operation. CONSTITUTION:Where the exterior-side blower 7 is controlled by a pressure switch 9 under an overload of heating, the defrosting operation is performed only after a compressor 1 is operated for a period of time equal to or longer than a period of time set on a timer 14. When the temperature of an exterior- side heat exchanger is higher than a temperature set by a deforsting temperature setting part for the heat exchanger, a defrosting operation judging part operates the blower 7 through an exterior-side blower controlling part, prior to switching the four-way valve 2 by a four-way valve controlling part. A timer 15 is started at the moment the blower 7 is started, and when the period of time counted by the timer 15 reaches a preset period of time, the valve 2 is switched by the four-way valve controlling part, thereby stopping the defrosting operation. Simultaneously with starting and stopping the defrosting operation, a room-side blower 4 is operated by a room-side blower controlling part. Accordingly, the refrigerant noise and vibrations generated when switching the four-way valve for the defrosting operation are reduced. |
