The presence of humidity into experimental gas mixtures is generally nocuous for some kind of equipments used in the gas distribution systems and for the filtering units. Conversely it can be required in many applications: in the RPC detectors of the ATLAS experiment for instance, the humidity is mandatory for the correct usage of detectors under radiation, but it tends to quickly saturate the filtering modules installed on the gas distribution system. A method to intensively extract the moisture or, in alternative, to exchange it from the incoming gas line stream toward the filtering system to the outgoing one is presented: based on special porous membranes, the solution can reduce the rate of the filters regeneration from the estimated 1 regeneration every 24-36 hours to 0.5-2 regenerations per month, saving up sizable amount of regeneration gas, expenditures of energy and fresh experimental gas to recondition the filtering cartridges.