The bypass adapter allows targeted control of the supply and exhaust air flows. The inflowing air into the system is dried by a GIEBEL Adsorber. On the other hand, the outflowing air flows out through the stainless steel valve either into the environment or into a screwed-on pipe for targeted discharge, e.g. out of the build-ing. The internal ball-and-spring valve blocks the contact of the inside of the tank with the adsorber, so that particularly ag-gressive or sensitive substances can be efficiently ventilated.