World’s Whitest Paint

Researchers recently reported developing the whitest paint on record, capable of reflecting more than 98 percent of sunlight. As a result, it keeps surfaces up to 19 degrees Fahrenheit (approximately -7.22 degrees Celsius at typical outdoor temperatures) cooler than ambient temperature. In comparison, commercially available white paint reflects only 80 to 90 percent of the sun’s rays. Even heat-reflecting paints, which are made with titanium dioxide, only reflect wavelengths in the visible and infrared spectrum, but still absorb ultraviolet waves that cause the surface to increase in temperature.

After evaluating more than 100 different materials, the researchers found that barium sulfate – a compound currently used in cosmetics, photo papers and other products – offered the best performance. In addition, they discovered that boosting the concentration of barium sulfate by a factor of six and varying the size of the particles further improved reflectivity.

Testing resulted showed the ultra-white paint provided an average cooling power of 113 watts per square meter. Painted on the roof of a 1,000-square-foot building, that translates to 10 kilowatts. And unlike air conditioning that simply removes heat from indoors and moves it outdoors, the new paint transfers heat through the atmosphere into deep space to reduce global temperatures. Statistical modeling indicated that it could reduce the need for air conditioning by up to 70 percent in hot locales like Las Vegas or Phoenix. The new paint could be available to consumers in the next year or two at a cost that would be comparable to current products.