Abstract: A computer cooling system adapted to be installed in a drive bay of an existing computer casing to cool the inside of the casing. The cooling system includes a thermo-electric heat exchanger defining first and second superposed air channels respectively in heat transfer communication with the hot and cold sides of Peltier devices. The cooled ambient air is discharged into the computer casing while the heated ambient air is directed into an evaporator for evaporating the condensate formed during cooling of the air discharged into the computer casing.