Reflective roof paint repels the heat

On bright days, the rooftop of the Anaheim Hilton is so blindingly white that it looks like a mirror positioned directly at the sun. That dazzling glare might just be the greenest thing to happen to the top of a building since solar panels.

The white coating deflects nearly 85% of the heat that hits it, reducing the surface temperature by as much as 50 degrees. That means less energy is needed to cool the hotel's interior, cutting air-conditioning costs and carbon emissions.

This is no ordinary coat of paint. Designed by an 82-year-old former military scientist from the Inland Empire, the tinted topcoat is filled with tiny hollow glass balls that deflect heat, layered over a waterproof undercoat made of recycled rubber.

The Hilton spent more than $150,000 on the project, which was completed in March. That's $300,000 less than the cost of a conventional repair to the old, leaky roof, said Jerome Annaloro, director of property operations at the hotel. If the reflective material cuts utility costs this summer the way management anticipates it will, Annaloro said, he will recommend white roofs for the entire Hilton chain.

"I was skeptical at first . . . but the product spoke for itself," he said. "It's a win-win."

Americans spend about $40 billion a year to cool buildings, according to U.S. government figures. So-called cool roofs are being touted as a simple, inexpensive way of lowering surface temperatures on the tops of structures by as much as 100 degrees, cutting operating costs and slowing climate change.

Energy Secretary Steven Chu, a Nobel Prize winner in physics, recently called for all roofs to be painted white to promote saving energy. Some scientists suggest that covering dark tar roofs with light-colored coatings could help mitigate the "urban heat island" effect. Development has raised temperatures markedly in many cities, leading to more energy use and smog as well as greater numbers of deaths during heat waves, experts said.

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