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GAF's First Urban Heat Project Produces Cool Results

GAF coatings had been proven to cool surfaces and ambient air on individual applications but had never been applied on a community-wide scale. Preliminary data showed a 25-50% reduction of the urban heat island effect during peak temperatures.

Last year, roofing and waterproofing giant GAF launched the GAF Cool Community Project — a novel initiative assessing and addressing the urban heat island effect. GAF partnered with Climate Resolve, Pacoima Beautiful, and other grassroots community organizations and government partners to investigate the impact of urban heating in the Los Angeles neighborhood of Pacoima.

Just north of downtown LA, Pacoima doesn’t get the cooling effect of the nearby ocean; so it’s uniquely hotter than the surrounding region. Like other underserved communities, Pacoima suffers disproportionately from heat-related stressors compared to adjacent neighborhoods.

In July 2022, GAF applied its StreetBond solar-reflective pavement coating to a 10-square-block area in Pacoima — approximately 700,000 square feet of ground surface including roads, parking lots, playgrounds, basketball courts, a school yard and more. GAF’s StreetBond reflective coatings can reflect upwards of 60 percent of sunlight, essentially bringing a surface’s albedo (its ability to reflect heat) back into balance with the Earth’s surface.

Each month, measurements were taken for temperature, barometric pressure, dew point, air speed and direction, long- and short-wave radiation, albedo and more. Two remote weather stations in the community provided another layer of real-time data. Simultaneously, an adjacent five-square-block control community received the same measurements. Months of measurement data established baseline temperatures for Pacoima.

Seven months into the project, preliminary data analysis showed a 25-50 percent reduction of the urban heat island effect during peak temperatures, and 13-21 percent improvements across all day and night hours. Average ambient air temperature saw 1.5°F cooling during sunny days. On very hot days, cooling reached 3.5°F with 10°F reductions in surface temperatures.

The team was surprised to discover that communities downwind from Pacoima were also experiencing cooling effects from 0.2-0.5°F. Jeff Terry, VP of Corporate Social Responsibility & Sustainability at GAF, wondered if just one community has such an effect, what could an entire city do? That’s the entire point of the project, he explained: To create a model and proving ground for other municipalities to adopt in the fight against scorching urban heat.

“What we wanted to do [in Pacoima] was learn and demonstrate what’s possible,” Terry said. “Hopefully, this will be a model that can demonstrate what’s possible for other municipalities across the country.”

GAF’s coating technology had been proven to cool surfaces and ambient air on individual applications; but the company had never applied it on a community-wide scale.

“[GAF] has done lab tests on things; but you never quite know until you take a comprehensive, community-based approach to doing this,” he said. “This has never really been done before. But if you look at it more comprehensively than just one single-lane mile or a single basketball court, you can actually see some cooling solutions at the community level.”

Image credit: GAF

Anecdotally, community members say they are using air conditioning less often; feel better letting their kids out to play on hot days; and report increased tire and shoe longevity. And community cooling reaps rewards beyond comfort: Cooler communities can reduce cooling-related energy costs and emissions, and actually provide net long-term cooling effects similar to reducing carbon emissions.

Starting in August, a number of residential houses will receive new roofs with GAF solar-reflective technology. Together with community-wide data gathered from phase one, the team hopes to paint a holistic picture for how solar-reflective surfaces affect all aspects of a community.

The project puts no financial burdens on the community, thanks to GAF’s partnerships with Climate Resolve, Pacoima Beautiful and the Global Cool Cities Alliance (though organizational changes led the latter to prematurely pull support). Working with organizations representing the community is central to the success of this type of project, Terry explained.

“They’ve been incredible partners in helping us get to know the residents of Pacoima,” he said. “We’ve also had great partnerships with government agencies, which have been critical in doing the actual work.”

GAF sussed out community needs and sentiments via these local partners, then brainstormed how it could provide solutions.

“It’s critical — going into communities and asking the residents about their needs and what’s happening there,” Terry said. “We’re open to partnering with everybody. It’s not us saying, ‘Hey, this is the best way to go;’ but something that needs to be demonstrated with a community-wide approach to addressing heat.”

GAF and its partners will use what they’ve learned about climate-resilient communities to develop a roadmap for scaling reflective coatings elsewhere. The company is speaking with other municipalities interested in taking the model to cities in other climate regions. With record-breaking heat throughout the world this summer, the call for climate-resilient communities is a poignant one; and new incentives in the Inflation Reduction Act and other state and federal legislation are finally providing the financing needed to scale adaptation solutions and save lives.

Reflective coatings such as StreetBond will play a huge role in heat mitigation, Terry explained — considering the nation’s millions of square miles of roadways, parking lots, roofs, and other hard surfaces all contributing to sweltering urban heat. But reflective coatings are not a silver bullet, he warned. They should be part of a suite of other tools — including increasing greenspace and tree canopies, and other innovative solutions.

“No silver bullets here,” Terry cautioned. “We just need to make sure that the toolbox is full.”

GAF says a comprehensive, phase-one project report will be published by mid-September 2023 and will later be submitted for peer review.