The Fraunhofer Institute for Solar Energy Systems (ISE) – a German research center – has developed a building façade panel that acts as a low-temperature heat source for domestic heat pumps as part of its TABSOLAR III research project.
“Heat pumps are currently seeing something of a boom in the heating technology market,” says Fraunhofer ISE in a statement. “However, not every property has sufficient space to accommodate the external air unit needed for an air-to-water heat pump.”
The solar thermal panels, which are made from ultra-high-performance concrete, are designed to offer a noiseless and space-saving alternative to external air units, it adds.
According to the research institute, the panels also act as an “attractive architectural feature.”
Heat absorption
Each of the TABSOLAR panels feature channels of “solar fluid” that absorbs the heat from the sun’s radiation and surrounding air. The absorbed heat is then transferred into the heat pump circuit via a heat exchanger.
The channels are configured in a branched pattern similar to the veins found in leaves or the human body. This structure was created using Fraunhofer ISE’s bionic FracTherm process.
“Using this process, it is possible to create an evenly distributed network of channels across almost any shaped panel, which ensures uniform flow distribution and also a lower energy consumption rate for the pump,” explained the research institute.
The prefabricated panels have been developed for suspended rear-ventilated façades, which reduce heat loss from a building and protect it from external environmental factors.
“Our simulations suggest that both new builds and older retrofitted building stock would have sufficient façade space for this purpose,” explained Dr. Michael Herman, Project Manager at Fraunhofer ISE and coordinator for the TABSOLAR III joint research project.
The institute noted that there is potential to adapt the concept for other construction facades in the future.
Range of applications
The TABSOLAR brand includes a range of façade panel options to suit different applications.
TABSOLAR Premium panels are glazed with “spectrally selective coatings” that can generate higher temperatures. This range is more similar to conventional solar thermal collectors and is designed for domestic hot water heating and backup heating, explained Fraunhofer ISE.
TABSOLAR Economy offers medium temperatures for domestic hot water production or solar combination systems.
TABSOLAR Design is an unglazed panel that can be personalized with different color and surface-structure options. This product was developed as a low-temperature heat source for heat pumps used for domestic hot water heating or swimming pools.
Inside a building, panels from the TABSOLAR Heat & Cool range can be used as “thermally activated building systems” for heating and cooling.
Industry collaboration
Funded by the German Federal Ministry for Economic Affairs and Climate Action, the TABSOLAR III project is coordinated by Fraunhofer ISE in collaboration with a range of industry partners.
Throughout the development and testing of the panels, the stakeholders have been involved in the project.
“Right from the outset, this has been an interdisciplinary project,” explained Herman. “We have pooled expertise from the relevant solar technology and construction sectors to develop an innovative and architecturally attractive solution which we hope will further the energy transition in the building industry.”
“We have pooled expertise from the relevant solar technology and construction sectors to develop an innovative and architecturally attractive solution which we hope will further the energy transition in the building industry.”
Dr. Michael Herman, Fraunhofer ISE
In addition to the façade panels, a range of tools have also been developed as part of the project, including an augmented reality app for visualizing the panels in situ and an online configuration tool to aid the design process.
There are also plans to ensure the technology can be integrated into Building Information Modeling processes.
Fraunhofer ISE presented a demonstration façade showcasing sample panels from its TABSOLAR Design range at the BAU architecture trade fair, which took place in Munich, Germany, from April 17 to 22.
A prototype of the complete solution will be developed for testing and monitoring.
