Abstract: An improved, flexible habitation cooling system combines an evaporative cooler having a cold water circuit communicating with heat exchange means for cooling the interior of the habitation and a compression refrigeration system. In one embodiment means are provided in a cold water circuit for circulating cooled water from the evaporative cooler into a heat exchanging coil in an air plenum and back to the cooler for re-use. The expansion coil of the refrigeration apparatus communicates with the cold water circuit in heat exchange relationship to further cool the cold water before it enters the coil in the air plenum. In an alternative embodiment wherein the expansion coil is disposed in the air plenum, the cold water circuit is also disposed in the air plenum upstream of the expansion coil.