Saving Power by Demand Capacity Controlled Compressor

We quantified the effect on the power reduction of the car air conditioner, in low cabin heat load and in high-speed vehicle cruising. Using a demand capacity control compressor, both the reduction of the excessive cooling capacity and the improvement of refrigeration cycle efficiency are possible. We studied how to operate the demand capacity control compressor effectively. We found out the following things as results.

1. 1.
   By using cycling clutch control when the ambient temperature is low (<20degC), and capacity control when the ambient temperature is high, power can be saved.
2. 2.
   Demand capacity control compressor and system can save 29% of the energy that the A/C system consumes in a year. Therefore the system result in a 22% reduction of the fuel consumption penalty that normally results from use of the A/C system.
3. 3.
   Demand capacity control compressor and the system can reduce the fluctuation of the discharge air temperature by 37%, and can reduce torque load to the engine.