Seems illogical but this process was demonstrated as far back as 1878, when Augustin Mouchot demonstrated the production of ice blocks using a solar driven Adsorption Chiller.
As in a refrigeration circuit, the refrigerant changes its physical form from a liquid to a gas and back again. Every time the refrigerant changes back and forth in it’s physical state, the refrigerant absorbs and expels heat energy. But during the condensation stage (from gas to liquid) its temperature is reduced enough to be cold..
In this case the refrigerant is also water, therefore a non pollutant, in compared with the mass produced ozone depleting equivalent used in a traditional refrigeration system.
How Adsorption Chiller interfaces
The Adsorption Chiller has four internal compartments, two which contains silica-gel. The solar heated water is used to evaporate the refrigerant out of the porous absorbent silica-gel, at the same time it is pressurised into the top compartment. Another water circuit (condenser circuit used to heat the Swimming Pool) condensates the refrigerant (which creates the cool temperature) which is then used to saturate the Silica-Gel again……And so it goes on in an alternate semi continuous operation.
As there are not many mechanical moving components, the Chiller can last as long as thirty years, with very little maintenance required.