Cooling with sorption materials can be achieved through various forms. For example, air can be dehumidified isothermally with a concentrated saline solution (see also dehumidifying and cleaning) with the result that the air can be cooled down through direct humidification.
An ad- or absorption chiller respectively, uses sorption materials differently for cooling. Ad-/absorption of a working fluid in the ad-/absorber causes the working fluid to evaporate, which cools down the immediate surroundings. The low temperatures in the evaporator are used for cooling applications using heat exchangers. These machines can be operated in a steady or quasi-steady state and are driven with heat instead of electricity.
A major advantage for climate control in buildings is the temporary overlap of the heat supply through solar thermal collectors and the demand for residential cooling. However, this is not the case for numerous heating systems that use renewable energies. Usually as the natural heat supply decreases the demand for heating rises.
Independently from building climate control and solar thermal collectors, sorption chillers can be driven by excess heat sources at low temperatures that otherwise could not be used effectively for electricity generation.
