The "apparatus for evaporating salt brine"

operates as follows:

It extracts heat from a cooler location and transfers it to a warmer area using a specialized substance. In this process, heat is absorbed and released as the substance is compressed and expanded. In heating mode, the heat pump collects warmth from the air, water, or ground and delivers it to the building to be heated. In cooling mode, the process is reversed: the heat pump extracts warmth from inside the building and releases it outside. This way, the heat pump efficiently utilizes existing heat sources to heat or cool buildings.

With his "apparatus for evaporating salt brine," he became the creator of the first heat pump. According to his method, the steam generated could be used for heating or for further evaporation. Construction of an experimental apparatus began at the Ebensee saltworks in 1856. In the historic year of 1857, the prototype of the new "steam pump" went into operation at the Ebensee saltworks. This marked the world's first use of a "heat pump." With additional propulsion from hydropower, Rittinger estimated an annual saving of 32,000 cubic fathoms of wood (approximately 293,000 m³) for all Austrian saltworks.