What is not calculated is whether the cooler is even capable of condensing all the vapor and cooling it down to the desired temperature. In addition, of course, the distillate cannot become colder than the cooling water. For example, if the cooling water is 20°C, the lowest possible temperature of the distillate is also 20°C. However, if the computer calculates a temperature rise of 90°C, i.e. the cooling water at the cooling water outlet should have a temperature of 20 + 90 = 110°C, i.e. a temperature above the boiling point of water, the cooling water flow is too low and the cooling water temperature too high.
The main purpose of this calculator is to estimate whether the water flow is generally strong enough.