BY THE OPTIMIST DAILY EDITORIAL TEAM

What if your home could beat the heat by sweating, just like your skin? A team of scientists in Singapore may have just made that possible.

In a promising new development, researchers at Nanyang Technological University have created a cement-based paint that mimics the body’s natural cooling mechanism: sweating. Unlike typical commercial cooling paints that repel water to protect buildings, this new paint stores water in its porous structure and slowly releases it, evaporating heat away in the process.

“The key is passive cooling,” explains materials scientist Li Hong. That means the system works without electricity or any mechanical input. While many existing cooling paints use radiative cooling (reflecting sunlight and beaming heat into the sky) this method falters in humid climates, where moisture in the air traps heat and blocks it from escaping.

So the researchers got creative.

Triple-action technology

The new paint combines three forms of passive cooling: radiative cooling, evaporative cooling (think: how your sweat cools you), and solar reflection. It reflects an impressive 88 to 92 percent of sunlight, even when wet, and emits up to 95 percent of the heat it absorbs. To boost its performance, the team added nanoparticles for reflectivity and durability, along with a touch of polymer and salt to help retain moisture and prevent cracking.

After two years of real-world testing on three mini houses in Singapore, the results spoke for themselves. One house was painted with conventional white paint, one with a commercially available cooling paint, and one with the experimental sweat-inspired formula. The first two faded to yellow under the equatorial sun, while, as coauthor Jipeng Fei put it, “our paint was still white.” Maintaining that brilliant white color is essential for high reflectivity and consistent cooling.

Energy savings and climate resilience

Performance-wise, the new paint is impressive. It helped reduce energy use for air conditioning by 30 to 40 percent in test homes. And that matters: “Around 60 percent of building energy is used for space cooling,” notes coauthor See Wee Koh. If adopted widely, this kind of cooling paint could significantly slash electricity demand and help buildings stay comfortable with far less reliance on energy-guzzling air conditioners.

Beyond individual homes, the implications are bigger. Cities across the globe suffer from the urban heat island effect, where concrete-heavy environments trap and radiate heat. Air conditioning, while effective indoors, only worsens the problem by releasing hot air into already sweltering neighborhoods. In contrast, this paint emits heat as invisible infrared radiation, which escapes into the atmosphere without warming the immediate surroundings.

“Singapore has very severe UHI,” Koh points out, referencing the city’s intense urban heat island issue, “and so do other regions like the Middle East.” With climate change turning up the global thermostat, innovations like this could offer a passive, planet-friendly way to beat the heat.

Source study: Science— Passive cooling paint enabled by rational design of thermal-optical and mass transfer properties