A evaporative cooling device is described having a pair of heat conducting plates arranged in spaced, generally parallel relationship with spacing elements separating the plates from one another and defining primary and secondary flow channels between the plates. Inlet ducts are connected to the primary channels and outlet ducts connect from the primary and secondary channels. A water distribution system is also provided to supply water to the secondary channels such that a primary air flow through the primary channels may be cooled by heat conduction along the plates to cause evaporation of the water into a secondary air flow through the secondary channels.