Abstract: This invention uses an air to air heat exchanger to cool the air passing through an evaporative water cooler. This enables the evaporative water cooler to cool water to a temperature very near to the dewpoint temperature. The water so cooled may be used to remove heat from other media. One use of the cooled water is to remove heat from a habitation. This invention provides in hot arid climates a method of cooling air inside a habitation to a temperature providing comfort to the occupants at a much lower cost and at a much lower usage of electrical energy than previous methods.