an air drying system 8 employing two air dryer modules 10 as described herein was measured to have only 2 psi of pressure drop at full flow 40 cfm as compared to a conventional system having a substantially equal capacity and being operated under substantially equal parameters which had a measured pressure drop of 12 psi in other words according to such configuration air drying system 8 according to the present application had only one sixth the pressure drop of a conventional regenerative air drying system fig9 is a block and schematic diagram illustrating generally a compressed air system 120 including an air compressor 122 a storage container 124 for storing compressed and dried air a controller 126 e g a plc and a regenerative air dryer system 8 according to the present application including four air dryer modules 10 indicated as dryer modules 10 a 10 d as described above the housings 12 of the four air dryer modules 10 a 10 d are coupled together and form common input and output air passages 20 and 28 shared by air dryer modules 10 a 10 d in operation regenerative air dryer system 8 receives a supply of u201c wet u201d compressed supply air 40 from air compressor 122 via input air passage 20 dryer modules 10 a 10 d dry the wet supply air 40 by directing the air through desiccant canisters 14 and provide a flow of dry output air 42 to a storage container 124 e g pressurized tank via output air passage 28 according to one embodiment as described above after all of the air dryer modules 10 a 10 d are pressurized and regenerative air dryer system 8 is providing a stable flow of dry.