Rising temperatures are hitting cities hard. Due to crowded conditions and streets trapping heat, temperature fluctuations affect urban areas more than rural ones. Data from the UN shows that 55% of the global population lives in urban areas. By 2050, this number may be up to 68%, a clear majority. This means we need creative and innovative ways to cool down the places we live in.
Solar Reflective Paint Project in L.A.
In summer 2022, GAF, a roofing and waterproofing manufacturer, partnered with nonprofit Climate Resolve to paint the roads of Pacoima, L.A., with a solar reflective coating. The project covered a total of more than 1 million square feet. The area included basketball courts, schoolyards, and parking lots. A local artist even created a street mural with the paint.
Since launch, the project has been under study. Now, a peer-reviewed study by Altostratus, which also created California’s Urban Heat Island Index, found that reducing surface temperature was linked to a decrease in ambient air temperature. This refers to how hot (or cold) you would feel while walking around.
According to research, during heat waves, Pacoima had ambient air temperatures that were up to 3.5°F cooler than surrounding areas. On sunny days, these temperatures were up to 2.1°F cooler. The solar reflective coating also helped the pavement warm up slower before noon and also cool off faster in the afternoon. Also, the surface temperature of the coated pavement was, on average, 10°F cooler than non-coated areas during the day on sunny days.
Jeff Terry, the VP of corporate social responsibility and sustainability at GAF, sees promise in these results. In an interview with Forbes, he reported that many residents of Pacoima have told him how cooler they feel and how they can let children play outside without worrying about heat strokes.
A Good Solution?
While the paint project helped cool down Pacoima, it may be better used alongside other cooling methods. Shade can cool people by 20-45°F in places with hot and dry climate.
Even though the cooling effect is small, solar reflective paint can be an eco-friendly cooling option by reducing the need for AC units. They can also lower a building’s carbon footprint.
Beyond the Pacoima Project
As of now, GAF has applied the solar reflective coating, now named StreetBond, to 130 schools across the US. In January of this year, GAF used their paint on basketball courts outside of a community center in Kissimmee, Florida.
Their most recent project was in a middle school in Mableton, Georgia. As a bonus, the students learned to calculate how cooler the painted surfaces were compared to those without. The team is now making arrangements to bring their paint to Miami.
References:
https://www.fastcompany.com/91117672/something-amazing-happened-when-an-l-a-neighborhood-covered-its-roads-in-solar-reflective-paint
https://www.forbes.com/sites/jamiehailstone/2023/07/11/how-reflective-coatings-are-cooling-down-one-los-angeles-neighbourhood/
https://www.smartcitiesdive.com/news/los-anageles-cool-reflective-pavement-study-results-pacoima-extreme-heat/714420/
https://coolcalifornia.arb.ca.gov/how-cool-vegetation-works
https://ashbrookroofing.co.uk/blogs/general-guides/what-is-solar-reflective-paint-and-what-does-it-do
