How is the cooler approach calculated?

The cooler approach is calculated by taking the water temperature leaving the cooler and subtracting the saturation temperature (s.s.t.) at the corresponding pressure. This process gives insight into how effectively the cooler is removing heat from the water. The closer the water temperature leaving the cooler is to the saturation temperature, the more efficient the cooling process is.

This calculation is essential for evaluating the performance of the cooling system and determining whether it's capable of meeting the desired temperature levels. A smaller cooler approach indicates better performance, as it suggests that the system is effectively exchanging heat and maintaining low water temperatures.

In this context, other options involve different temperatures that do not accurately define the cooler approach, such as water temperature entering the cooler or temperatures related to the condenser or evaporator, which are not directly relevant to the specific evaluation of the cooler's effectiveness.