| 摘要 |
PURPOSE:To realize the precise management of operation and maintenance of the air conditioning device by a method wherein the automatic alarm of choking of an air filter is issued based upon the detected value of an inlet air temperature, and the difference between an outlet air temperature and said inlet air temperature of an operating heat exchanger. CONSTITUTION:The inlet and outlet air temperatures of an evaporator 5 in the air conditioning device are respectively sensed with a first and a second thermally sensitive elements 7 and 8. These sensed values are inputted in a calculating unit 10 in order to calculate the difference between the inlet air temperature and the outlet air temperature. On the other hand, the value, which subtract the outlet air temperature from the inlet air temperature under the choked state of the air filter, is memorized in advance as linear function of the inlet air temperature in a memory 12. When the time set with a timer unit 11 elapses after the start of a compressor, a comparator 13 compares the calculated result of the calculating unit 10 with the memorized value of the memory 12. If said calculated result coincides with said memorized value, an alarm device 14 is put into operation to issue the choking alarm of the air filter. |
