The bypass adapter enables a targeted control of the supply and exhaust air flows. The incoming air into the plant is dried by a GIEBEL adsorber. In contrast, the outflowing air is directed through the stainless steel valve either into the environment or into a screwed-on pipe for targeted discharge, e.g. out of the building. The internal ball-spring valve blocks the contact of the internal tank air with the adsorber, so that even particularly aggressive or sensitive substances can be efficiently ventilated.