The energy efficiency depends on the internal pressure drop and the electrical power consumed by the refrigerated air dryer.  

The internal pressure drop is the difference between the pressure of the compressed air at the refrigerated air dryer inlet and outlet pipe.

The lower the internal pressure drop of the refrigerated air dryer, the lower the pressure you need to achieve with the air compressor. And the less energy the compressor consumes. 

Our refrigerated air dryers are designed to minimize pressure drop and have therefore the lowest energy consumption.