The Paint That Cools Your Roof and Pulls Water From Thin Air
CLIMATE SOLUTION | PROF. DR. FAISAL IQBAL JAFRI
Australian researchers developed a nanoengineered cooling paint that reflects 96% of sunlight, lowers roof temperatures, reduces energy use, and harvests water from air, offering a sustainable solution to urban heat, drought, and climate challenges.
You don’t notice it at first. The roof above your head, baking under a summer sun, seems harmless enough. But in a city, that ordinary surface is quietly making life hotter, harder, and drier. Concrete, asphalt, and dark roofing absorb the sun’s energy like a battery storing heat, then release it slowly through the night. That’s the urban heat island effect in action, and it means your neighborhood can feel five or even ten degrees warmer than the fields just outside the highway. Now imagine if that same roof, the one adding to the problem, could flip the script entirely. What if it could cool your home without using a watt of electricity and pull clean water out of thin air at the same time?
That’s exactly what a team of researchers in Australia set out to build. Chiara Neto and Ming Chiu, scientists at the University of Sydney, were watching global temperatures climb and water reservoirs shrink. They knew that air conditioning makes things worse, guzzling energy and pumping waste heat back into the streets. So they asked a different question. Instead of fighting heat with more machines, why not design a surface that naturally stays cool? And if that surface gets cold enough, could it also collect the moisture that’s already floating above us, invisible but always there?
The result is a nanoengineered paint that does both. By 2022, their work had grown into a startup called Dewpoint Innovations. The coating works through a phenomenon called passive radiative cooling. Ordinary white paint reflects maybe seventy to eighty percent of sunlight. That’s decent, but it still heats up. Dewpoint’s formula, tested in a six month outdoor trial reported in 2025, pushed solar reflectance all the way to ninety six percent. The difference is dramatic. While a standard dark roof might sit there absorbing everything, Dewpoint’s surface actually stays cooler than the surrounding air. In a three month field trial in Sydney in late 2023, their paint ran up to thirty degrees Celsius cooler than a dark roof. For anyone paying an electricity bill, that matters. The trial estimated a thirty four percent drop in cooling energy use.
That kind of saving isn’t just good for the wallet. It’s a serious piece of climate adaptation. Distinguished Professor Baohua Jia, a nanotech expert at RMIT University in Melbourne who isn’t involved with Dewpoint, called the technology a tangible tool for dense urban areas. She believes it could drastically lower ambient city temperatures, reduce heat stress, and cut our collective reliance on air conditioning. And here’s where it gets even smarter. A surface that stays cold while everything around it warms up does something magical. It encourages moisture in the air to condense on its surface, just like a cold drink sweats on a humid day. That means Dewpoint’s paint doesn’t just repel heat. It can actively harvest water.
The company imagines this water feeding into existing rainwater systems for gardens or, with the right filtration, becoming drinking water for households. But Ming Chiu, the co inventor and chief technology officer, sees a more urgent use. During Australia’s catastrophic 2019 to 2020 bushfire season, he watched images of firefighters giving water to dehydrated koalas. That stuck with him. He realized that water capture systems could be deployed in the middle of nowhere, generating fresh water from the air so wildlife could drink during droughts when every creek and pond has turned to dust. It’s a quiet, low tech solution to a violent problem.
Dewpoint isn’t there yet, but it’s close. The company is preparing for larger trials across Australian rooftops and possibly overseas. They’ve already partnered with Haymes Paint, an Australian owned company, to bring the product to market. Andrew Brewer, who manages product strategy at Haymes, admitted that breaking into the construction industry is tough. Project builders tend to stick with what they know. Adoption will depend on independent testing, clear proof that the energy savings justify the upfront cost, and compatibility with standard painting methods. But he also sees the long term trend. As sustainability and heat management become bigger priorities in construction, demand for cooling products will grow.
So what will this paint actually cost? Aeka Mehta, another member of the Dewpoint team, said they expect to land around the same price as other functional paints, which typically run fifty to one hundred percent more expensive than regular paint. That’s not pocket change, but neither is replacing an overworked air conditioner every few years. And compared to the hidden costs of heat waves, blackouts, and water trucked in from hundreds of miles away, it starts to look like a bargain.
Of course, challenges remain. Radiative cooling paints can lose effectiveness over time as dirt collects on the surface. They perform better on clear nights than cloudy ones. And building codes haven’t really caught up, so there’s no standard way to measure or mandate this kind of technology yet. But Jia is optimistic. Materials are improving. Manufacturing is scaling up. She believes passive radiative cooling will play an increasingly vital role in cooling cities, cutting carbon emissions, and securing water supplies, all without consuming precious energy or relying on artificial refrigerants.
For Dewpoint, the ultimate goal is nothing less than a rewrite of urban planning. Mehta put it simply. He wants their paint to become part of the toolkit that city planners and architects use going forward, not as a niche product but as a standard feature. Imagine building codes that require new roofs to reflect heat and collect water. Imagine neighborhoods designed to cool themselves and produce their own moisture, block by block. It sounds like a dream. But so did a paint that stays colder than the air around it, until someone brushed it onto a roof in Sydney and watched the thermometer drop.
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About the Author
Prof. Dr. Faisal Iqbal Jafri writes on climate innovation, sustainability, emerging technologies and solutions shaping resilient communities and future cities.
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