Ultra-white paint could reduce the need for air conditioning

White houses are often boring, but they just might save the planet. As United States today reports, Purdue University researchers have developed an ultra-white paint (it just won a Guinness World Record) that reflects 98.1% of solar radiation while producing infrared heat. As this leaves the surface cooler than the surroundings (ordinary paint warms the surface), it could effectively replace air conditioning in some cases – it produces 10 kW of cooling power per 1000 m². ft of roof, or more than a typical air conditioning unit in a house.

There are existing paints designed to reflect heat, but they do not reflect more than 90% of sunlight and do not cool surfaces. The team didn’t have much leeway either – an even whiter paintwork could have compromised it.

The trick was to use a high proportion of barium sulfate, a compound often seen in cosmetics and photo paper, in different particle sizes. The wider size range allows more of the light spectrum to be dispersed and thus reflects more sunlight.

It’s unclear how close this extremely white paint is to your local store, but the researchers are fully committed to bringing their work to market. They have partnered with a company to mass produce and sell the paint and have already filed for patents. If it lives up to the bill, however, it could play an important role in tackling climate change. This could reduce or eliminate the need for air conditioning in some homes, especially in hot areas with lots of sunlight. This could reduce emissions and energy consumption, and could save you money on hot summer days.