Can painting the exterior of your home the right color eliminate the need for air conditioning? It sounds like science fiction, but it may soon be reality.
Scientists at Purdue University have created the world’s whitest paint — as certified by no less an authority than the Guinness World Records — and in the process possibly reduced the need for air conditioning.
The paint reflects 98.1% of solar radiation while also emitting infrared heat. Absorbing less heat than it emits allows the paint to keep the surface of the home cooler than the surrounding temperature.
The new paint differs from standard white paint, which reflects only 80% to 90% of sunlight. That prevents such paint from cooling the surface it coats.
By contrast, using the new paint over a roof area of about 1,000 square feet could create a cooling power of 10 kilowatts. Xiulin Ruan, a professor of mechanical engineering at Purdue, notes that such an effect is “more powerful than the air conditioners used by most houses.”
According to a Purdue press release:
“Two features make this paint ultra-white: a very high concentration of a chemical compound called barium sulfate — also used in photo paper and cosmetics — and different particle sizes of barium sulfate in the paint. 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.”
The Purdue researchers currently are partnering with a company to put the paint on the market. But until it becomes available, you can try to stay cool cheaply by using the tips in “How to Build Your Own DIY Air Conditioner in Minutes.”