At saturation condition dry bulb, wet bulb and dew point temperature are same with 100% relative humidity. The minimum temperature to which water can be cooled in cooling tower is equal to wet bulb temperature of air.

When a stream of moist air is passed over a cold and dry cooling coil such that no condensation takes place, n cooling is sensible cooling. It is along dew point temperature as it remains constant during sensible cooling.

During adiabatic saturation process, enthalpy and wet bulb temperature remains constant and dry bulb temperature decreases. In this dew point temperature increases.

The evaporative cooler performance is directly related to evaporate water at a given relative humidity. The temperature of water does not have a great effect upon cooling produced through evaporation.

When warm saturated air is cooled excess of moisture condenses. The relative humidity remains constant but specific humidity decreases due to which excess of moisture condenses.

The process involved is cooling and dehumidification. Since temperature of spray water is less than dew point temperature cooling and dehumidification will take place.

The valve of effective temperature is low in winter and high in summer. In winter it is 19 degrees Celsius and in summer 22 degrees Celsius. Therefore effective temperature is index which correlates combined effects of air dry bulb temperature, air humidity and air movement upon human comfort.

Wet bulb depression is difference between dry bulb and wet bulb temperature. Hence, when DBT = WBT implies that relative humidity =100%. Therefore when wet bulb depression is zero relative humidity is equal to zero.

Sensible heat factor is ratio of sensible heat and total heat is equal to latent heat plus sensible heat
SHF = SH/ (SH+LH), but LH = 0.25SH
Hence, SHF = 0.8.

At 100 RH, WBT = DBT = DPT. The temperature corresponding to saturation temperature at partial pressure of water vapor is called dew point temperature.