In the isothermal humidification process, the water vapour is dispersed in the environment after having been created by boiling water.
This procedure requires the contribution of an external source of energy to change the state of the water.
As the temperature of the water vapour is higher than that of the air, the temperature of the air tends to increase.
The adiabatic process does not involve the contribution of thermal energy from an external source: the water is finely atomised and introduced into the environment. The heat required to transform the water from liquid to vapour is supplied by the air, which is consequently cooled.
