What is the difference between fixed displacement and variable displacement car air conditioning?

[LeOwen]

The difference between fixed displacement and variable displacement car air conditioning is that variable displacement compressors generally have an additional control valve, while externally controlled variable displacement compressors have an extra set of control lines. Fixed displacement air conditioning: When the car's air conditioning is turned on, pressing the A/C button and hearing a "click" sound, along with the compressor starting to work and a momentary change in the dashboard RPM, indicates that it is a fixed displacement air conditioning system. Variable displacement air conditioning: Variable displacement air conditioning, also known as variable frequency air conditioning, is an air conditioning device that automatically adjusts the compressor frequency based on the set temperature and the ambient temperature. It can effectively save energy and reduce power consumption, but the price of such air conditioning systems is higher.