Fraunhofer ISE has developed solar thermal facade panels that act as heat pump sources in buildings. The solution is made of high-performance concrete for aesthetic architectural facades.
The Tabsolar invention consists of solar thermal panels made of ultra-high-performance concrete (UHPC). Between each panel are multi-branched cylindrical hydraulic tube channels with heat-absorbing solar fluid. The heat exchanger transfers this heat to the heat pump circuit.
“The design of the channel structures was created using the bionic FracTherm process developed by Fraunhofer ISE, which produces multiple branched (or fractal) patterns similar to veins in leaves or the human body,” the institute said in a statement. “With this process, it is possible to create an evenly distributed network of channels over almost any shaped panel, ensuring even flow distribution and also lower pump energy consumption.”
The dimensions of the solar thermal panels are 1,683 mm x 1,040 mm, which corresponds to a surface area of 1.75 m², according to Tabsolar’s website. They are available in glazed and unglazed versions. The unglazed variant is intended as a heat source for hot domestic water or heat pumps for swimming pools. It can be designed in different colors and with other surface structures. Glazed panels with spectrally selective coatings can reportedly produce higher temperatures and are therefore designed to be used for domestic hot water heating and backup heating, as well as traditional solar thermal collectors.
“Our simulations suggest that both new buildings and older retrofitted building stock would have sufficient facade space for this purpose,” said Dr. Michael Herman, Tabsolar III Joint Research Project Coordinator and Project Manager at Fraunhofer ISE. He stated that the goal of the project is to demonstrate that the BIPV solution is a silent and space-saving alternative to air units outside air-to-water heat pumps.
Prefabricated Tabsolar panels have been developed for suspended rear-ventilated facades (VHF), but according to Fraunhofer ISE, they can potentially be applied to composite exterior insulation and finishing systems or sandwich wall systems. The panels can also be installed inside buildings as thermally activated building systems (TABS) for heating and cooling.
Fraunhofer ISE will present its Tabsolar panels at the BAU trade fair for architecture, materials and systems from 17 to 22. April at Messe München. The Tabsolar III research project is funded by the German Federal Ministry for Economic Affairs and Climate (BMWK) and supported by several partners.