GUWAHATI: Researchers at the Indian Institute of Technology Guwahati (IIT-G) have developed smart windows for automatic climate control of buildings, which can come handy in times of Covid by resisting the spread of the virus in residential apartments. These smart glasses can find applications for efficient automatic climate control in vehicles, locomotives, airplanes and greenhouses of the future. As Covid-19 has imposed an unprecedented risk of cross-infections through aerosol transmission in public buildings where central air-conditioning systems are in use, the experts believe that their smart windows can provide an alternative solution for maintaining ambient indoor temperature, thereby reducing the need of air-conditioning. Dr Debabrata Sikdar, assistant professor at the electronics and electrical engineering department of IIT-G, along with his research scholar, Ashish Kumar Chowdhary, from the premier technology institute, have designed the smart window materials that can effectively control the amount of heat and light passing through it in response to an applied voltage. The researchers said such smart window materials would help develop efficient automatic climate control systems. “At present, the Covid-19 pandemic has imposed an unprecedented risk of cross-infections through aerosol transmission in public buildings such as healthcare centres, offices, transportation systems, workshops, laboratories and food storage facilities where central air-conditioning systems are in use,” said Sikdar. “There has been increased attention to sustainable architectural designs for better light and heat management in buildings in recent years, and deploying smart windows is the first step for such structures,” Sikdar said. Conventionally, window designs are static and they are predesigned for specific climatic conditions. “The emergent smart windows, on the other hand, can dynamically adjust the amount of light and heat radiation entering a building in response to external stimuli, thus conserving the building’s energy,” he added. According to the United Nations Environment Programme, buildings around the globe account for 36% of energy use and 39% of energy-related carbon dioxide emissions annually. The climate control system, where energy-consuming devices are used to maintain comfortable indoor temperature and brightness, is the source of primary consumption of energy in buildings. “A building’s heating, cooling, and lighting loads are major energy-consumption segments in any building. To meet the goals of the Paris Climate Agreement, a building’s energy intensity- how much energy buildings use-will have to improve by 30% by 2030,” a IIT-G spokesperson said. “We have proposed an electro-tuneable glass made of two ultra-thin metal layers sandwiching an electro-optic polymer whose refractive index can be changed by applying a small voltage, which allows filtering of visible and infrared radiation,” explained researcher Ashish Kumar Chowdhary.