The two towers are filled with adsorbent material (keeping on the surface, outside). It has been designed to filter H20 molecules by a physical sieve method. The H2O molecules attached to the surface of the adsorbent material can easily be separated from the place where they are attached by the effect of molecular forces. While the 1st tower dries the inlet humid air, it is replaced with the fresh air passing through the 2nd tower in the opposite direction. This is a physical reaction and can be applied numerous times.
This process is normally performed between the two towers alternately with 10-minute intervals. The process is listed as drying, pressure balancing and refreshment. In the AK-DAB model, ~15% of the dried air is consumed continuously in the refreshment process.