This New ‘Sweating’ Paint Could Keep Homes Cool Without AC

Who needs an AC when your house can just sweat it off?
In a breakthrough that sounds almost too wild to be true, a team of scientists at Nanyang Technological University (NTU) in Singapore has developed a revolutionary sweating paint. This cement-based coating mimics the human body’s natural cooling process—releasing stored water as temperatures rise, which then evaporates to cool the surface.

It’s a simple but powerful form of passive cooling technology, and one that could reduce our dependence on energy-hungry air conditioners.

How the Sweating Paint Works

The paint contains a hydrogel matrix—a water-absorbing polymer. At night or during cooler hours, it pulls moisture from the air. As the day heats up, the paint releases this water in tiny droplets that evaporate and cool the surface.

This evaporative cooling process can lower surface temperatures by 6°C to 10°C (11°F to 18°F). Unlike conventional reflective coatings, which only bounce back sunlight, sweating paint actively cools surfaces—making it especially effective in humid climates.

Because it works without electricity or machinery, it’s a fully self-regulating solution—ideal for rooftops, building exteriors, or areas with limited access to energy.

A Future with Passive Cooling

With climate change intensifying heatwaves, demand for cooling is expected to triple by 2050. But air conditioners, while effective, contribute to the problem by consuming electricity and releasing greenhouse gases.

Sweating paint offers a low-cost, energy-free alternative. Climate advocates have long dreamed of solutions like this—simple, scalable, and sustainable. It’s particularly promising for developing regions and low-income communities where heat is rising but cooling access remains limited.

Researchers are now testing durability, color options, and large-scale production. Future applications could expand to vehicles, temporary shelters, and even wearable tech—marking a bold step forward in sustainable urban design and a meaningful win for the planet.

Read further on Science News.