How does the 'approach temperature' of a cooling tower affect the overall system efficiency?

The approach temperature of a cooling tower significantly affects the overall system efficiency. The approach temperature is defined as the difference between the cold water temperature leaving the cooling tower and the entering wet-bulb temperature of the air. A lower approach temperature indicates that the cooling tower is performing more effectively, delivering colder water to the condenser. Colder condenser water results in a lower condensing temperature and pressure....