When researchers in Singapore began painting three small houses with different paints, they probably didn't imagine that after two years of tropical sun and rain, they would solve one of the most pressing problems of modern cities. Traditional reflective paint and regular paint yellowed, while their new formula remained perfectly white. But color is just the beginning: This porous reflective paint “sweats” like human skin, reflects 92% of sunlight even when wet, and cuts air conditioning consumption by up to 40%. The future of urban cooling has just found a home, ladies and gentlemen.
A reflective paint that does not give in to humidity
Most reflective paints work well in deserts, poorly in the tropics. The problem is always the same: moisture traps heat near surfaces, rendering traditional radiative cooling useless. Researchers from Nanyang Technological University They have overcome the obstacle by combining three cooling strategies in a single reflective paint.
Li Hong and his team created a cement-based formulation that reflects sunlight, radiates heat into space, and most importantly, “sweats.” The porous structure retains water and releases it slowly, just like our skin does. The result? A reflective paint that maintains 88-92% reflectivity even when wet.
The test that is worth more than a thousand simulations
Two years of direct observation in Singapore is worth more than any computer model. Jipeng Fei, co-author of the research published on Science, says that while other paints yellow after a few months of tropical climate, their reflective paint “was still white.”
The numbers speak for themselves: homes painted with the new formulation consumed 30 to 40% less electricity for air conditioning. As we have already observed, super-reflective paints represent a promising frontier, but this time a crucial element is added: the ability to function even in high humidity conditions.
Reflective paint, the recipe is simple: nanoparticles, polymers and a pinch of salt
The recipe seems almost alchemical, but it is pure materials engineering. Nanoparticles maintain high reflectivity and strengthen the structure. A small amount of polymer and salt helps retain moisture and prevents cracks. The whole thing is assembled in a cement matrix that emits up to 95% of the absorbed heat in the form of infrared radiation.
See Wee Koh, the study’s third author, points out that “about 60% of building energy globally is used to cool spaces.” Reflective paint doesn’t just save energy: it sends heat directly into the space instead of venting it into the surrounding air, helping reduce the urban heat island effect.
Singapore as a laboratory of the future
Singapore has transformed this research into urban policy. The Housing Development Board is extending the use of reflective cladding to all public buildings by 2030, after trials in Tampines confirmed temperature reductions of up to 2°C.
Reflective paint is no longer a laboratory experiment. It is a mature technology waiting to be applied on a large scale in cities that suffer the most from urban heat. One paintbrush at a time, one wall at a time, towards a slightly cooler future.
