IIT Researchers develop smart windows that regulate light, heat, conserve power in buildings
Temperature control (heating / cooling) and lighting are considered to be the predominant energy-consuming resources in large buildings and office complexes that use traditional glass windows. Researchers at IIT Guwahati claim to have developed smart window materials that can control the amount of light and heat that penetrates through voltage when voltage is passed through it. They say this can help develop efficient automatic air conditioning systems in buildings.
Intelligent window materials developed by the researchers use precious metals and their comparatively inexpensive alternatives. According to Ashish Kumar Chowdhary, an IIT Guwahati research scientist, their design was to have an electro-optic polymer sandwiched between ultra-thin layers of metal. Filtering of light would thus be made possible by applying a voltage and changing the index of refraction (how light moves through a material) of the electro-optic polymer.
When running simulations, the researchers considered using gold and silver as the outer metal layers, but ran the tests with copper and indium tin oxide. Researchers claim that under certain conditions, the smart glass could selectively filter solar radiation that spans the visible, infrared, and short-wave infrared wavelengths, including heat and light reflected from neighboring buildings and structures. The results of this study were recently published in the journal Solar Energy Materials and Solar Cells.
The team believes that such intelligent materials can be used to achieve efficient automatic air conditioning in vehicles, locomotives, airplanes and greenhouses of the future. They claim that the material proposed by their team can be easily made using existing state-of-the-art nanoscale manufacturing processes such as electron beam evaporation and graphoepitaxy techniques. According to the researchers, the processing of these materials depends on the surface smoothness and other physical properties of the layers. The team plans to conduct further studies on the subject.
“We believe that our smart windows can provide an alternative solution to maintaining the interior temperature and lighting in a building or vehicle by incorporating them into standard glass windows or walls, reducing the need for air conditioning,” said Dr. Debabrata Sikdar, Assistant Professor, Faculty of Electronics and Electrical Engineering.