Scientists create whitest paint that would eliminate need for air-conditioning

Scientists have created the world’s whitest paint in a lab in Purdue University, which could soon eliminate the need of air conditioners. The paint has already made its way to the Guinness Book of World Records as the whitest.

Xiulin Ruan, a professor of mechanical engineering at Purdue University says, “When we started this project about seven years ago, we had saving energy and fighting climate change in mind.” The scientist at the university had aimed to make a paint that would reflect sunlight away from a building structure.

In creating a paint that would reflect 98.1% of solar radiation and emit infrared heat, the paint became really white. When applied to a building the paint will not absorb heat and will instead, emit it, making the surrounding and indoor temperature cooler without consuming any power. Ruan predicts that a roof of 1000 square foot covered in this paint will have a cooling power of 10 kilowatts, which is more powerful than most air conditioners in houses.

The paint’s whiteness also means that the paint is the coolest on record. Using high-accuracy temperature reading equipment called thermocouples, the researchers demonstrated outdoors that the paint can keep surfaces 19 degrees Fahrenheit cooler than their ambient surroundings at night. It can also cool surfaces 8 degrees Fahrenheit below their surroundings under strong sunlight during noon hours.

The paint's solar reflectance is so effective, it even worked in the middle of winter. During an outdoor test with an ambient temperature of 43 degrees Fahrenheit, the paint still managed to lower the sample temperature by 18 degrees Fahrenheit.

This white paint is the result of six years of research building on attempts going back to the 1970s to develop radiative cooling paint as a feasible alternative to traditional air conditioners.

Commercial white paint gets warmer rather than cooler, since general paints that are designed to reject heat, reflect 80-90% of sunlight and can’t make surroundings cooler. Researchers at Purdue have partnered with a company to begin selling the ultra-white paint and make it available for everyone.