| 摘要 |
PURPOSE:To enable the presence or absence of frosting to be detected securely and with a high accuracy, by a method wherein the temperature of an interior coil of an air conditioner is detected, and defrosting is started when the gradient of temperature fall exceeds a set gradient at the time of heating. CONSTITUTION:At the time of the heating operation, an interior fan motor 27 is driven, and electric currents are supplied to a relay 17 for driving a compressor, a relay 18 for an exterior fan and a coil 9 for a four-way valve, so that the four-way valve is changed over to a heating cycle and both the compressor and the exterior fan are driven. Thereafter, when the exterior coil is frosted and a coolant-evaporating action in the coil is lowered, the temperature of the interior coil is also lowered. The temperature of the interior coil is detected by a sensor 12, and whether or not the gradient of the temperature fall has exceeded a set gradient is discrminated by a microcomputer 1. When an output YES is generated three times successively, the compressor and the exterior fan are stopped and the four-way valve is changed over to a defrosting cycle. |
