Patent ID: 7238105

Claim:
Dewpoint cooler, comprising: a first air circuit and a second air circuit thermally coupled thereto via an at least partially heat-conducting wall, through which two circuits can flow two respective media, wherein at least the second medium contains a gas, for instance air, with a relative humidity of less than 100%; wherein the heat-conducting surfaces of said wall are at least partially covered in the area of the secondary medium with a hydrophilic, for instance hygroscopic coating, which coating is for instance porous and/or can absorb water by capillary action, retain it and relinquish it again through evaporation, such that the wetted coating, and thereby also the heat-conducting surfaces, are cooled; primary drive means based on pressure difference, for instance a fan or pump, for the primary medium; secondary drive means based on pressure difference, for instance a fan, for the secondary medium; and a wetting unit for subjecting the secondary medium to wetting by the water by evaporating liquid from the coating such that the evaporated liquid entrained by the secondary medium extracts heat from the primary medium via the heatconducting wall; characterized by said heat-conducting wall having break-up means such as fins for breaking up at least the thermal boundary layer, the laminar boundary layer and the relative humidity boundary layer at the position of at least active zones in both media for heat transfer, which break-up means comprise heatconducting protrusions which enlarge the effective heatconducting surface area of said wall; said break-up means also being at least partly covered in the area of the secondary medium with a hydrophilic, for instance hygroscopic coating, which coating is for instance porous and/or can absorb water by capillary action, retain it and relinquish it again through evaporation, such that the wetted coating, and thereby also the break-up means, are cooled; a housing in which the walls bounding the air circuits are accommodated, which housing is adapted as border or frame, or a part thereof for an outside door or outside window of a building, wherein the inlet of the primary circuit and the outlet of the secondary circuit are situated on the outside and the outlet of the primary circuit and the inlet of the secondary circuit are situated on the inside.