The answer to this question is the place where the compressed air expansion tank is installed. When installed inside a compressor room or production hall, the refrigerant dryer can be installed downstream of the compressor upstream of the expansion tank. However, it must be preceded by e.g. a cyclone separator, when there is no compressed air aftercooler on the compressor, and a 1 micron pre-filter. Thanks to this, condensate with water will not accumulate in the expansion tank, which will slow down its wear process. When the expansion tank is installed outside the compressor room (in an open space), it is worth installing the dryer behind the expansion tank when the compressed air system is directed back to the buildings, e.g. in the compressor room or other room. However, you should always remember about the additional installation of the automatic condensate drain under the tank, because in it the process of sudden cooling of the compressed air and water condensation takes place. In this case, too, you should not forget to install a filter at the inlet to the refrigerant dryer.