heinrich böll foundation berlin
few, but highly innovative technology ensures extremely low energy consumption. It is not cooled by a refrigeration machine, but by water. Rio-Therm balustrades are located along the window fronts in all offices. They contain a high-performance heat exchanger through which water at a temperature of 20° C circulates in summer. A small fan in the sill unit ensures that the cooled air is distributed throughout the room. Even with outside temperatures of 30° C, the room temperature does not rise above a maximum value of 25° C. The cooling water required for this is produced by a so-called adiabatic recooler of the KW25 type: city water is sprayed onto its pipes. This produces evaporative cooling, which reduces the cooling water temperature back to 20° C. Thus cooled, the water is returned to the circuit. The advantages of the system are obvious: conventional air-conditioning systems require water with a temperature of 8-10° C. The cooling water is then reheated to 12° to 18° C in the room. This swallows up an unnecessary amount of energy. With the system used in the Heinrich Böll Foundation, no temperature jump is necessary. As a result, cooling here is more efficient by a factor of 10 than with conventional systems.