This simple product keeps buildings cool

In the rural, South African town of !Kheis — which means “a place to live” in the Khoi language — temperatures are hot, often topping 40 degrees C.

Corrugated metal homes in low-income neighborhoods of this part of the Northern Cape province have proven to be ideal for testing a new “cool coatings” technology from U.S. and African researchers.

The Global Cool Cities Alliance brought U.S. companies and universities together with their counterparts in South Africa to test the cool-coatings technology. The U.S. Department of Energy helped to pay for the venture.

Man with hand on white corrugated wall (Theresa Scheepers)
Bipin Shah from WinBuild Inc. explains how the white reflective surface works. (Theresa Scheepers)

Cool paint deflects heat

The testing process worked this way: Rooftops and exterior surfaces were prepped and painted with a coating engineered to reflect the sun’s heat.

Bipin Shah, president of WinBuild Inc., a project partner that tested glazing systems, says the coatings can deflect 80 to 90 percent of the sun’s heating rays, maintaining a comfortable temperature inside structures.

“The inside of the house is much cooler, even though there is much heat on the outside,” he said. The paint, manufactured by several U.S. companies, is affordable for low-income communities.

Before the buildings were painted with cool coatings, it was impossible to stay inside them on a hot day, according to resident Oom Isaac. But he and other residents say that, since the paint was applied, their homes are comfortable in hot or cold weather.

To make this happen, the project team connected U.S. coatings manufacturer Topps Products with !Kheis and other interested parties. Topps now has a company presence in South Africa and is one of several participating U.S. companies, including EPOX-Z and EnviroECOats.

Three workers dressed in blue on rooftop (PEER Africa)
Workers apply a “cool coating” to a roof in !Kheis. (PEER Africa)

The !Kheis project team included the Lawrence Berkeley National Laboratory and the University of Florida, which ran training sessions on using the technology, from installation to software development. A partnership between the University of Florida and the University of Pretoria offered online training.

Workers can enroll in an industry-recognized, nationally certified training program especially designed for the project.

The South Africa Energy Efficiency and Renewable Energy Exchange provides updates on the project and resources for other communities interested in similar programs.

The project was largely funded through the U.S. Department of Energy’s Energy Efficiency and Renewable Energy International Team, which supports the deployment of clean energy technologies and the growth of a strong market in South Africa. Twenty-two U.S. companies are participating in the project, including Dow Chemical, which also contributed financially.