Principle of a clay cooler

Bild Schematic diagram:The evaporation process on the surface of a ceramic cooler is shown schematically. The ceramic cooler made of fired clay was soaked in cold water and then removed. The pores of the ceramic filled up with water. If a cold beverage bottle is then placed inside, it will stay cold for a relatively long time in the ceramic cooler, even if the surrounding temperature is higher. As the water evaporates from the pores of the ceramic cooler, heat is constantly extracted from the air in the interior of the clay pot (evaporation heat and some adsorption heat). As a result, the air inside the clay pot stays cold, as does the bottle placed inside.