The scarcity of wood

sparked the inventive spirit of Peter Ritter von Rittinger

To evaporate the brine, the Ebensee saltworks required so much wood that the surrounding forest area was completely depleted. This made the procurement of fuel increasingly difficult and expensive. In 1853, Peter Ritter von Rittinger, a trained physicist and mathematician, patented his "evaporation process," specifically developed for the salt production process. His method was based on the works of Carnot, a French physicist who, through his theoretical analysis of the steam engine, established a new branch of science, thermodynamics. Rittinger's innovation enabled an energy saving of 80 percent compared to the conventional wood evaporation process.

With this "apparatus for evaporating salt brine," he created the first heat pump. His method allowed for the use of the generated steam for heating purposes or for re-evaporation. Construction of an experimental apparatus began in 1856 at the Ebensee saltworks, and in 1857, the prototype of the "steam pump" went into operation, marking the world's first use of a heat pump. Rittinger predicted an annual saving of 32,000 cubic fathoms of wood (approximately 293,000 m³) in all Austrian saltworks through the additional use of hydropower.

Commercial dissemination began in the first half of the 20th century and varied depending on the political situation in different countries, until finally in 1945, the first ground-source heat pump was introduced to the market. By the early 1980s, 46 heat pump systems had been installed in Upper Austria, including large-scale installations such as the municipal office in Ebensee, many of which are still in operation or can be visited today.

Despite declining energy prices after the second oil shock, a group of Upper Austrian companies specialized in installing this innovative heating system, laying the groundwork for the success of the heat pump in Austria.