New research suggests that a special type of paint could significantly reduce urban heat. This “cool paint” reflects sunlight, keeping cities cooler and more comfortable for residents.
While using paint to combat urban heat isn’t a new idea, a recent study by Nanyang Technological University (NTU) provides the first real-world evidence of its effectiveness. Researchers in Singapore coated roofs, walls, and roads in an industrial area with this special paint. The paint contains additives that reflect sunlight, reducing heat absorption by buildings and streets.
Cooler Cities in Real-World Testing
Previously, studies on cool paint relied on simulations or small-scale models. This NTU experiment is the first to test it in a real-world setting. By comparing a painted area to an unpainted control area, researchers were able to measure the impact on temperature and comfort.
Over a two-month period, they monitored air movement, surface and air temperature, humidity, and radiation. The results were impressive: the painted area saw a 30% reduction in heat radiating from buildings and streets. This translated to a significant temperature drop, with the painted area being up to 2°C cooler during the hottest part of the day.
Reduced Heat Absorption Benefits Everyone
The special pigments in cool paint reflect sunlight, reducing heat absorption. During peak sun hours, rooftops coated with cool paint reflected 50% more sunlight and absorbed 40% less heat compared to conventional roofs. This not only cools the surrounding environment but also helps to keep buildings cooler, potentially reducing the need for air conditioning.
The study also found that cool paint made the area more comfortable for pedestrians. Thermal comfort levels were measured using a standardized index that considers temperature, humidity, wind, and radiation. Pedestrians in the painted area reported feeling about 1.5°C cooler.
A Promising Solution for a Warming World
These findings offer a valuable tool for cities struggling with heatwaves and rising temperatures. “Cool paint provides a minimally disruptive solution for urban cooling,” explains Dr. Kiran Kumar Donthu, lead author of the study. “Unlike other options that require major construction, cool paint offers an immediate impact.”
By reducing heat absorption in buildings, cool paint can also lead to lower energy use. This benefit extends beyond hot climates like Singapore. “As the world warms, people everywhere will be looking for ways to stay cool,” says Associate Professor Wan Man Pun, lead investigator of the study. “Our research shows that cool paint can be a viable strategy to combat the urban heat island effect.”
The NTU team plans to continue their research, focusing on the long-term durability of cool paint in the same test location.