Bosch: making a virtue out of necessity

In 1852, William Thomson published a paper on refrigerators that worked on the principle of compression. In reverse, he suggested, they would also be excellent for heating. In his research on “heating machines,” Thomson showed that they would require much less primary energy than conventional direct heating. Peter Ritter von Rittinger is regarded as the inventor of the first heat pump: a system for evaporating brine that he presented in 1853. The process yielded an energy saving of 80 percent compared to the conventional evaporation process using wood. In other words, the contemporary scarcity of wood was the trigger for the development of this pioneering patent.