Absorption Chiller

An absorption chiller cools by using a heat source, rather than an electrically driven compressor, to drive its refrigeration cycle, so it can run on solar energy, waste heat or district heating instead of electricity; it circulates two coolants, one that evaporates to draw heat out of its surroundings and is then absorbed into a second liquid, with applied heat later separating the two fluids and restarting the cycle, and because it has no moving parts it runs almost silently. William Cullen laid the scientific groundwork for the process in 1748, Ferdinand Carré invented practical absorption cooling using water and sulfuric acid in 1858, and Baltzar von Platen and Carl Munters improved the design in 1922 with a three fluid version that needed no pump at all; commercial production began under the company AB Arctic in 1923 to 1925, later acquired by Electrolux. Absorption chillers are especially useful where electricity is unreliable or expensive, and they are central to trigeneration systems, which use the waste heat from a gas turbine to produce electricity, hot water and air conditioning in sequence, raising the turbine overall efficiency.