Abstract: There is disclosed a new and improved cooling system and method for cooling the air in an enclosed space. The cooling system includes a cooling tower having a plurality of fans arranged to cool a first fluid and a chiller including a condenser thermally coupled to the first fluid, a compressor, and an evaporator. The chiller further includes first conduit means for carrying a refrigerant. A chilled fluid loop including second conduit means circulates a second fluid through the evaporator for cooling the second fluid and is arranged to flow air over the second conduit means and into the enclosed space for cooling the air in the enclosed space. Fan control means controls the speed of the cooling tower fans to minimize the total power consumption of the fan motors and the compressor.