Published in the journal Sustainable Cities and Society in March this year, researchers from Nanyang Technological University (NTU) applied coatings containing additives that reflect solar heat to rooftops, walls and pavements in Singapore's industrial estates. In a warming world, paint could be a key tool in making cities more comfortable for work and play.
How cool paint can help reduce heat in cities?
After they applied cold paint to one area of the city, they compared the temperature and comfort levels to adjacent unpainted areas.
The researchers measured air flow, surface and air temperature, humidity and radiation over two months and found that the coated areas released 30% less heat from the building surface. This results in temperatures dropping as low as 2 degrees during the hottest times of the day.
The coating contains additives that reflect the sun's heat, successfully reducing surface heat absorption and dissipation. Roofs with a cold paint coating reflect more sunlight during the hottest times of the day on a sunny day than conventional roofs. 50%, absorbs less heat than 40%, lowering the temperature in the area by about 1.5 degrees, making it more comfortable for pedestrians.
The least invasive solution for urban cooling
The findings could be invaluable to cities looking for quick, cheap ways to combat the damaging and worsening effects of heat waves.
"This is a minimal-impact solution to urban cooling, with immediate results compared to others that often require massive urban redevelopment to deploy," said Kiran Kumar Donthu.
By reducing the amount of heat absorbed by urban structures, it could also cool buildings and reduce the need for indoor air conditioning, he added.
This is useful not only in cities like Singapore, which are hot year-round, but also in other urban areas affected by global warming.
Lead researcher Associate Professor Wan Man Pun said: "As the world warms, people will increasingly look for ways to stay cool."
"Our study validates how cool paint coatings can be a strategy to reduce the urban heat island effect in the future."
The NTU team will conduct further research focusing on how the cold paint coating remains unchanged over time at the same experimental site.
Source:
euronews.green (2024.04.01) 'A minimally intrusive solution for urban cooling': This paint could make cities feel 1.5C cooler
