An Israel-based tech firm has developed a paint that cools down when exposed to sunlight, potentially offering an electricity-free cooling system for buildings.
According to the New Scientist, the firm SolCold was inspired by the counterintuitive principle of laser cooling, where specially designed materials cool by up to 150°C when hit by lasers. They decided to come up with a material that could do the same in sunlight and therefore be applied to roofs of buildings.
According to Yaron Shenhav, Co-Founder of SolCold, this amazing paint works “like putting a layer of ice on your rooftop, which is thicker when there is more sun.”
The paint is made up of two layers – an outer layer that filters out some of the sun’s rays, and an inner layer that converts heat to light and emits it away from the building. Titanium dioxide is used in the outer layer to allow radiation ranges to be transferred to the bottom layer.
During testing, when applied to roofs and ceilings, the paint has successfully lowered the temperature of rooms by 10°C. The firm predicts that with the paint, buildings can lower their energy consumption by up to 60 percent, massively reducing their electricity bills and carbon emissions at once.
Titanium dioxide is already used in light-scattering paint applications to reduce the amount of heat buildings absorb, but this is the first time it has been used to actively reduce the temperature in the building.