Homes Chilled Without Air Conditioners!

Homes chilled without air conditioners! Is there any chance?

A team of Electrical engineering researchers at Stanford University have succeded in designing a new form of a very thin material structure (1.8 micron)  that cools our buildings even when the sun is shining.

The study published in Nature in the November 2014 issue, shows that the use of this innovative coating is designed to equip the roofs and reduced the temperature of a room by five degrees without using any source of energy.

Shanhui Fan, the paper’s senior author said, “We’ve developed a new type of structure that reflects the vast majority of sunlight, while at the same time it sends heat into that coldness, which cools manmade structures even in the daytime.”

In fact, this innovative coating is designed to be installed on roofs. It reflects the sunlight and 97% of solar radiation like a mirror, thus avoiding the heat to penetrate inside the building. In addition, the material has another truly innovative feature, which is to absorb the heat present inside homes and discharge it outwardly without heating the ambient environment.

Radiative cooler prototype Image credit : AP Raman et al. Nature 515, 540-544 (2014)

Eden Rephaeli, a co-first-author of the paper, said “No one had yet been able to surmount the challenges of daytime radiative cooling – of cooling when the sun is shining,… It’s a big hurdle.”

As for now, it is a prototype but these results demonstrate that a tailored photonic approach can fundamentally enable new technological possibilities for energy efficiency. The results of the study demonstrate that, if a house has its roof covered by 10%  with this new radiative cooling panel, it would offset 35% of its entire air conditioning needs.