Indian Institute of Technology Guwahati (IIT Guwahati) researchers– Dr. Debabrata Sikdar, Assistant Professor, Department of Electronics and Electrical Engineering and research scholar, Ashish Kumar Chowdhary—have designed a smart window material that can effectively control the amount of heat and light passing through it in response to an applied voltage. Such smart window materials would help developing efficient automatic climate control systems in buildings.The study has been published in the journal, Solar Energy Materials and Solar Cells.
Conventionally, window designs are static, i.e., 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. “At present, the COVID-19 pandemic has imposed an unprecedented risk of cross-infections through aerosols transmission in public buildings such as healthcare centres, offices, transportation systems, workshops, laboratories and food storage facilities etc., where central air-conditioning systems are in use. We believe that our smart windows can provide an alternative solution for maintaining ambient indoor temperature and lighting inside a building or a vehicle by integrating those with usual glass windows or walls, thereby reducing the need of air-conditioning systems,” said Dr. Debabrata Sikdar.
The smart glass material proposed by the IIT Guwahati team can easily be fabricated using existing state-of-the-art nanoscale fabrication methods such as e-beam evaporation and graphoepitaxy techniques. “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 Ashish Kumar Chowdhary.
The primary consumption of energy in buildings is by the climate control system, in which energy-consuming devices are used to maintain comfortable indoor temperature and brightness. Hence, 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 percent by 2030.