Limitations of Component-Based Efficiency Regulations for Compressed Air Systems

In order to reduce the energy consumption of electric motor driven systems (EMDS), single components of these EMDS have been regulated regarding their efficiency. By introducing the extended product approach in DIN EN 61800-9, compressors have been reduced to simple load machines of power drive systems (PDS). This suggests the need to improving the component efficiencies even more and to link the PDS efficiency to the compressor package, instead of considering the overall energy consumption of the application, process, or system, which includes the complete compressor package. A comparison of motor efficiency with compressor package efficiency using the same electric motor but different compressor technologies is given and reveals that the efficiency of a compressor package primarily independent of the EMDS when looking at the total operating range. Three practical examples are given to emphasize the application-oriented wire-to-process overall performance as the key measure of the package. The various possible operation modes of not only a single compressor package but also even a whole compressed air station have to be taken into account for a holistic point of view. The paper concludes that a life cycle and application approach is the most efficient way forward toward real energy savings.