How does compression cool water in a household water cooler? I was reading and it says, " The water inside the water cooler is fed into a reservoir, where it is cooled using a refrigerant. A refrigerant is a cooling medium that is circulated in pipes that are located close to the reservoir in the water cooler. The refrigerant changes from a liquid to a gas as it moves in the pipes towards the reservoir because of the pressure in the pipes created by a compressor inside the water cooler. The cooled gas in the water pipe is forced through a valve to make it even colder. When the refrigerant is in a gas form and is circulating in the pipes, it has the ability to absorb the heat away from the mineral water in the reservoir, leaving cool and refreshing water that is readily available. The heat in the refrigerant is then expelled from the water cooler." Could someone not only explain the science behind this, but also the general engineering behind it? Thank you!