White houses are often boring but may help save big on your air conditioning bills and ultimately save the planet.
Researchers at Purdue University have developed the world’s whitest paint that has earned a Guinness World Records title. According to the researchers, coating your home with the world’s whitest paint may dramatically reduce or even eliminate the need for air conditioning.
The idea was to create a paint that would reflect sunlight away from a building; however, making this paint really reflective also made it really white. The formulation that professor Xiulin Ruan’s lab-created reflects 98.1% of solar radiation while emitting infrared heat. Because the paint absorbs less heat from the sun than it emits, a surface coated with this paint is cooled below the surrounding temperature without consuming power.
Currently, commercial white paint is designed to reject heat, reflect only 80-90% of sunlight, and can’t make surfaces cooler than their surroundings.
To make this paint really reflective, it was also necessary that it should be made really white. For this, the researchers used a very high concentration of a chemical compound called barium sulfate with different particle sizes. What wavelength of sunlight each particle scatters depends on its size, so a wider range of particle sizes allows the paint to scatter more of the light spectrum from the sun.
They claimed that covering a roof of about 1,000 square feet with the whitest paint would allow a cooling power equivalent to 10kW that would be more powerful than the central air conditioners used by most houses.
Now, the researchers plan to put this ultra-white paint on the market. They’ve already partnered with a company to mass-produce and sell the paint and have already filed patents.