New reflective coating will keep homes of the future cooler

As the dazzling buildings on the Greek island of Santorini demonstrate, painting your home white helps to keep it cool. Wearing white clothes is also a good way of beating the heat on hot days.

But it isn’t easy to keep white clothes clean, and some of us like a bit more colour in our lives. Thankfully, a new ultra-reflective coating will offer a kaleidoscope of cooling colours to choose from.

Yuan Yang, a materials scientist at Columbia University in New York City, and colleagues have developed a specialised paint coating made from two layers. The bottom layer is made using a porous polymer that scatters and reflects infrared light; the upper layer is a commercial coloured paint.

Testing carried out on a sunny summer’s day showed the black version of the two-layer paint kept an object 15.6C (28.8F) cooler than standard black paint. If applied to a building the scientists estimate their coating could reduce solar heating on a wall by 10-20%.

The research, reported in the Science Advances journal, suggests the new coating is adaptable and could be used to paint buildings, cars and even textiles, giving the residents of Santorini the option of a colour change.