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Liquid windows and the energy-efficient buildings of tomorrow

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On this episode of Futuris, we look at groundbreaking new technology that could hold the key to energy-efficient buildings of the future. We went to Sofia, Bulgaria, to find out how it works.

They look like ordinary windows but they're not. Inside each pane, there is a continuous flow of distilled water and glycol. The windows have been designed by researchers and architects working to create the energy-efficient buildings of tomorrow. The technology is being tested at an experimental pavilion in Sofia.

Inside each window, there is a constant flow of 70 litres of distilled water and 30 litres of ethylene glycol, which serves as antifreeze. Each transparent panel acts as an individual solar collector. Using solar cells, the windows absorb solar radiation and turn it into thermal energy to heat the building's interior.

"The advantage of using liquids instead of air inside the glass is that water is denser, so it absorbs infrared light in a broader range" says Miglena Nikolaeva-Dimitrova, physicist at the Bulgarian Academy of Sciences.


Scientists at this European research project are using the experimental pavilion to test the system's efficiency. Temperature and humidity are constantly monitored inside the building to see if energy can be produced and used long term or in very different climatic conditions.


Scientists want the water flow smart glazing system to ensure energy efficiency, not to act just as a transparent insulator. So the system must be able to maximize solar heat during the winter and avoid overheating in the summer. Scientists think the technology could help design the so-called "Nearly Zero Energy Buildings" of the future, as the European Union seeks to dramatically increase the energy efficiency of new building designs.


Researchers say the system's technology is now ready to be scaled up to industrial production. "We can now launch the product on the market," says Dieter Bruggemann, Professor of Thermal Engineering at the University of Bayreuth and an InDeWaG project coordinator. "Of course, we have to prove that it also works on bigger buildings besides these prototypes which are already running successfully. But we do think that it is now worth installing it in full-scale buildings".

While waiting for investors to get involved, measurements at the demonstration pavilion in Sofia will continue for the next 10 years.


Read the full article here.