Researchers at Nanyang Technological University in Singapore have developed a unique cement-based paint that cools buildings by mimicking the human body’s ability to sweat. This innovative material provides an energy-efficient alternative to air conditioning, especially in hot and humid climates where most cooling paints are less effective.
Most commercial cooling paints rely only on reflecting sunlight or radiating heat. However, this new paint combines three strategies: radiative cooling, solar reflection, and evaporative cooling. Most importantly, it uses water held in its porous structure to mimic perspiration. As the water slowly evaporates, the surface cools—just like sweat cools human skin.
This approach makes it ideal for use in humid environments. Traditional paints tend to repel water, which limits their cooling effect in such conditions. In contrast, this paint performs well even when humidity is high, allowing heat to escape more effectively from building surfaces.
The paint’s base is made from cement, which makes it easy to apply on common building materials. To boost performance, the team added nanoparticles. These increase the paint’s reflectivity and help it stay white over time. Unlike other paints that may turn yellow or degrade, this coating remains bright and functional after years of exposure to sunlight and rain.
In addition, small amounts of polymer and salt are included. These additives help retain moisture in the paint and prevent cracking, further extending its durability.
To test the paint, the scientists applied it to three small houses. One used regular white paint, another used a commercial cooling paint, and the third used the new formula. After two years, only the new paint stayed bright white. More importantly, the house with this coating used 30 to 40 per cent less electricity for air conditioning.
This paint doesn’t only benefit individual buildings. It can also help reduce the urban heat island effect, which makes cities warmer than surrounding areas. While air conditioning releases hot air into the environment, this paint emits heat as invisible infrared radiation. As a result, it cools buildings without warming the air around them.
In densely built cities like Singapore or areas in the Middle East, this could make a big difference. It offers a low-energy way to reduce both indoor and outdoor heat levels.
This material opens new possibilities for architects, interior designers, and urban planners. Its passive cooling ability, long-term durability, and energy-saving performance make it a smart choice for sustainable buildings. As climate challenges grow, such innovations are key to creating comfortable, low-impact environments.
Source: Science News
Photo: Polina Tankilevitch