To mention only the most important decision characteristics. Every system manufacturer and operator of adsorption drying installations is called upon to list all aspects relevant to the particular application, thus facilitating a purchase decision. It would be irresponsible to arrive at a universally valid statement advocating or rejecting a particular system without an adequately based evaluation. The wide range of applications, from the small receiver mounted compressor to the sophisticated compressed air plant, have to be considered in a different manner.