International News
THE NEW WHITEST PAINT
IS HERE – AND IT ’ S THE COOLEST . LITERALLY
In an effort to curb global warming , Purdue University engineers have created the whitest paint yet . Coating buildings with this paint may one day cool them off enough to reduce the need for air-conditioning , the researchers claim .
In October ( 2020 ), the team created an ultra-white paint that pushed the limits of how white paint can be . Now they ’ ve outdone that . The newer paint not only is whiter but also can keep surfaces cooler than the formulation that the researchers had previously demonstrated .
“ If you were to use this paint to cover a roof area of about 1 000 square feet , we estimate that you could get a cooling power of 10 kilowatts . That ’ s more powerful than the central air conditioners used by most houses ,” said Xiulin Ruan , a Purdue professor of mechanical engineering .
The researchers believe that this white may be the closest equivalent of the blackest black , “ Vantablack ,” which absorbs up to 99.9 % of visible light . The new whitest paint formulation reflects up to 98.1 % of sunlight – compared with the 95.5 % of sunlight reflected by the researchers ’ previous ultra-white paint – and sends infrared heat away from a surface at the same time .
Typical commercial white paint gets warmer rather than cooler . Paints on the market that are designed to reject heat reflect only 80 to 90 % of sunlight and can ’ t make surfaces cooler than their surroundings .
The team ’ s research paper showing how the paint works was originally published in April 2021 as the cover of the journal ACS Applied Materials & Interfaces .
6
RACA Journal I June 2021 www . hvacronline . co . za