Energy Efficient Water Windows

Windows account for about 40 per cent of building energy costs. To find a solution to the problem, researchers at University of Toronto turned to nature. Researchers at the University of Toronto say they can improve the energy efficiency buildings by fitting window panes with tiny channels of water. The scientists says that these channels, inspired by vascular systems in nature such as the network of blood vessels in the human body, can provide 7º to 9º C of cooling in the summer, and reduce heat loss during winter. The researchers developed a sheet of transparent flexible polymer with a cooling layer of clear silicone, inside which there are the tiny channels with a cross section 1 or 2 mm high and 100 micrometers across. Through these, room temperature water was circulated to and from an external source at a rate of 2 ml per minute. Because the temperature of the water is lower relative to the window, it is able to absorb heat energy and take it away. The process would be the opposite during the winter, when room temperature water would supply heat to the rest of the window. In either case, the idea is that the window would become a more effective barrier to convective heat transfer, making the building more energy efficient. They also suggest that different liquids could be used for various aesthetic effects such as altering color and transparency which could very well be utilized in futuristic architecture. The artificial vascular network layer Schematic of the composite window structure



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