| 摘要 |
PROBLEM TO BE SOLVED: To reduce refrigerant noise incident to switching of a four-way valve by providing a control means for stopping a compressor by decreasing the operational frequency thereof when a switching is made from heating operation to defrost operation or from defrost operation to heating operation. SOLUTION: An air conditioner 10 comprises an indoor unit 11 having a heating circuit 11a and an electronic expansion valve 11b, and an outdoor unit 12 having a compressor 12a, a four-way valve 12b, a cooling circuit 12c, and a control section 12d. The electronic expansion valve 11b is set with a heating operation opening during heating operation and set with a defrost operation opening during defrost operation. The four-way valve 12b is switched to the heating circuit 11a during heating operation and switched to the cooling circuit 12c during defrost operation. The control section 12d does not stop the compressor 12a immediately upon transition from heating operation to defrosting operation but stops the compressor after lowering the operating frequency thereof to the lowest frequency. The compressor is controlled similarly when a transition from defrosting operation to heating operation. Since pressure difference is suppressed, switching noise of the four-way valve 12b is lessened. |
