After the well house, the next station for the brine is the thermal technology room. In addition to the three heat exchangers and numerous pipelines, there is also a coarse filter with a 25-micron filter insert installed here. This ensures the protection of the subsequent technical equipment. From this filter, the brine flows into the heat exchangers, where its thermal energy is transferred to the processed heating water.

For this process, the 56 degrees Celsius warm brine and the cooler heating water flow past each other in a counterflow principle, separated by thin metal in all three heat exchangers. Therefore, there is no direct contact between the heating water and the brine. By the end of this process, the heating water is warmed to 56 degrees Celsius, and the brine is cooled to around 20 degrees Celsius.

The heat exchangers are three metal frames, each roughly the size of a wardrobe. Inside, there is an array of countless metal cells. The 322 plates in each array create a surface area of about 300 square meters per heat exchanger. Through these cells, thermal energy is extracted from the brine and transferred to the heating water.

The Schwerin brine contains 149 grams of salt per liter, giving it a salinity of 14.9 percent. For comparison, the Mediterranean Sea has a salinity of 3.8 percent, and the Baltic Sea in the Mecklenburg Bay has a salinity of about one percent. Due to its high salt content, Schwerin brine is suitable for therapeutic applications. However, in contact with technical equipment, it quickly leads to corrosion damage. Therefore, the deep water leaves the geothermal heating plant immediately after its heat is extracted and heads towards the injection well, avoiding contact with other equipment.

The metal cells in the heat exchangers are made of titanium, making them resistant to the salty brine. The thermal technology room is filled with many pipelines due to the two separate water circuits: colorful plastic pipes for the salty brine and steel pipes for the heating water. Each circuit also includes a supply and return line. For instance, the warm brine flows into a heat exchanger through an inlet and then returns cooled towards the injection well through an outlet. Additionally, the thermal technology room contains a pressure equalization tank, ensuring consistent pressure within the system up to the injection well, and the aforementioned coarse filter.

The heating water, warmed to 56 degrees Celsius in the thermal technology room, is then directed to the heat pump room, where it is further heated by the heat pumps.