Researchers at the Indian Institute of Technology (IIT) Guwahati have developed an alternative for AC (air conditioning) that the IIT claims is not only affordable and efficient, but also operates without the use of electricity. The innovation called ‘Radiative Cooler’ coating material can be applied on the rooftops and works both during the day and at night to provide an alternative to traditional air conditioners.
How Radiative Cooler works?
According to the researchers, passive radiative cooling systems work by emitting heat absorbed from their surroundings in the form of infrared radiations that can pass through the atmosphere before being dumped into the cold outer space.
Most passive radiative coolers operate only at night. For daytime operation, these coolers need to reflect entire solar radiation as well. Till now, these cooling systems are not able to provide sufficient cooling during the daytime. IIT Guwahati Researchers set out to resolve these issues and bring out an affordable and more efficient radiative cooling system that can operate round the clock.
Facts of Radiative Cooler:
• The theoretical design of the radiative cooling system has been tested and verified against rigorous computer-based simulations.
• This patterning free design of radiative cooler is large-area compatible and hence, also less prone to imperfections during the fabrication process, said the IIT.
• It is expected that the cooling power to be obtained after the construction of the cooler is going to closely match the calculations.
• With this innovation, cooler manufacturers can now explore radiative cooling to make electricity-free cooling systems.
“The team hopes this will reach the market once the large-scale prototypes are developed and tested for operational stability and durability under different climatic conditions. They are now working towards this,” said the IIT in an official notice.
Who are involved in creating radiative cooler
Ashish Kumar Chowdhary, Research Scholar at IIT Guwahati under the supervision of Prof. Debabrata Sikdar, Assistant Professor, Department of Electronics and Electrical Engineering, IIT Guwahati, along with his research team has designed and modeled such a passive radiative cooler.
“Instead of a single layer, the team cascaded silicon dioxide and aluminum nitride thin film layers on a silver layer, used as a ground metal, placed over a silicon substrate. The cooler they designed achieved about 97 per cent reflectance for solar and atmospheric radiations and 80 per cent emissivity for radiations in atmospheric transmittance wavelengths. The net cooling power is estimated to be 115 Wm−2 which could reduce ambient temperature up to 15 degrees below the outside temperature,” said the IIT in a statement.
