Abstract: The present invention relates to a method of producing multiple channels for use in a device for exchange of solutes between at least two fluid flows. The invention further relates to such a device. At least a first and a second sheet are comprised. The method comprises the steps of providing at least one of the first and second sheets with at least one profiled surface and joining the first and second sheets together with the profiled surfaces facing against each other. Channels are formed by the shape of the profiled surfaces.

Abstract: Device for exchange of moisture, between at least two counter-current gas flows (A, B), comprising a generally closed chamber (1, 101) having an inlet (7, 107) and an outlet (8, 108) for a first gas flow (B), such that the first gas flow flows in a first direction from the inlet to the outlet inside the chamber; and at least one duct (2, 102), which extends inside the chamber, generally in parallel with the first direction, which duct (2, 102) is arranged to conduct a second fluid flow (A) in an opposite direction to the first direction and which duct (2, 102) comprises a duct wall material with high permeability to water.