| 摘要 |
PURPOSE: An air conditioner is provided to reduce power consumption, and to prevent lowering of the indoor temperature by changing defrosting restriction time according to external air temperature and outdoor heat exchanger temperature for starting defrosting corresponding to external air temperature and RPM(Revolution Per Minute) of a compressor. CONSTITUTION: A control device(8) starts a defrost prohibition timer wherein defrosting prohibition time is increased with the decrease of outside air temperature, and reads the outside air temperature detected by an outside temperature sensor(7), an outdoor heat-exchanger temperature detected by an outdoor heat- exchanger temperature sensor(6), and RPM of a compressor detected by an RPM sensor(13). The outside heat-exchanger temperature is calculated when starting defrosting. When the value of a defrosting prohibition time timer elapses and exceeds the given defrosting prohibition time and the outdoor heat-exchanger temperature reduces to the value lower than temperature at which defrosting is started, a four-way valve(5) switches from a heating cycle to a cooling cycle and enters defrost operation. When the defrost operation is completed, a defrosting operation time timer and the defrosting prohibition time timer are reset.
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