Effectiveness of Cooling Tower For a given type of cooling tower, a closer (smaller) approach temperature indicates a more effective tower. Selecting a cooling tower with a close approach will supply the cooler water … but the capital cost and energy consumption of the tower will be higher, too. Note that effectiveness refers to the thermal efficiency of the cooling tower fill and the evaporative process; do not confuse this with the mechanical efficiency of the cooling tower. The mechanical efficiency refers to the fan power that’s required to circulate ambient air over the cooling tower fill. Different types of cooling towers differ in their mechanical efficiencies.
