A dewpoint cooler comprises: two medium circuits coupled mutually via a heat-conducting wall, through which circuits two media can flow, wherein the second medium contains gas, which wall has heat-conducting protrusions; wherein the wall and the protrusions are covered with a hydrophilic coating which can absorb an evaporable liquid and relinquish it again through evaporation such that the wetted coating, and thereby also the heath-conducting surfaces and the protrusions, are cooled; a wetting unit for subjecting the secondary medium to wetting by the evaporable liquid by evaporating liquid from the coating such that the evaporated liquid entrained by the secondary medium extracts heat from the primary medium via the heath-conducting wall. The coating consists of a porous technical ceramic material, such as a mineral wool.