What is the meaning of approach, pulb temprature and dew point which are related to cooling water?

Question

What is the meaning of approach, pulb temprature and dew point which are related to cooling water?

Answer 1

I am not quite sure what you are asking - if you are cooling air - the approach temperature is the temperature of the air stream as it enters the cooling coils - the coils can remove heat and lower temperature until the temperature reaches the inlet dewpoint, then the cooler has to remove the latent heat of vaporization to condense water from the air, as it cools the air stream further (removing much more energy from the air at that point).  the exit stream of air from the cooler is then at saturation - dewpoint = temperature.  To 'dry' the air, typically, the air stream is cooled beyond where you would like the room to be, to remove additional moisture, then the air is heated slightly to return it to the desired temperature.