The GIEBEL adsorber of the VARIO PA-R_NBR series are high-quality ventilation dryers with an aluminum valve part and a refillable cartridge. Furthermore the GIEBEL adsorbers are equipped with NBR seals. The desiccant and all wearing parts can be exchanged very easily. In the valve part are integrated large valves for the aeration and deaeration, which work frost-proof and ensure a low pressure build-up even on large systems. The replacement of the saturated and discolored desiccant can be done anywhere and very quickly by removing the cartridge.