Smog-eating tile arrives in California
Smog-eating tile – it almost sounds like something out of a science fiction movie. But it's real, and it's in Southern California, with KB Home installing smog-eating tile on houses in several communities.
The concrete tiles are manufactured by Irvine, Calif.-based Boral Roofing and they neutralize smog-forming nitrogen oxides produced by most vehicles. During a 12-month period, the concrete tile roof on a 2,000-square-foot house can neutralize the same amount of nitrogen oxides as a car's engine typically produces during 10,800 miles of driving, said Craig LeMessurier, director of corporate communications for Los Angeles-based KB Home.
What makes this possible is that the tiles contain titanium dioxide, which is a naturally occurring substance that Boral Roofing incorporates into the tiles' surface, said John Renowden, vice president of product development for Boral Roofing.
Titanium dioxide is a photo catalyst, so when the tile's surface is expose to ultraviolet light, as found in daylight, it breaks down the nitrogen oxides in the air into harmless calcium nitrate. This process works on both sunny and cloudy days, Renowden said.
"Calcium nitrate is fertilizer. When that washes off the roof that fertilizes your garden. It's a very mild fertilizer," he said.
Extensive European laboratory testing and field studies from 2002 to 2006 proved the smog-fighting ability of the tiles, he said.
The tiles were shown to the public last year in Lancaster, Calif. The enthusiastic response led KB Home, a national homebuilder, to begin offering it in all of its housing developments in southern California in January. The Lancaster home is zero energy with solar systems, factory backups and smog-eating tile, making it the first residential roof application in the U.S., Renowden said.
The roof is a standard feature in some KB Home communities and, in others, it is an upgrade that averages an extra $800. Air quality in a neighborhood can improve is the tiles are installed on many homes, because it reduces the smog-creating potential of vehicles in the area, LeMessurier said.
The Boral Roofing tiles appeal to homeowners interested in green homebuilding because while there is no direct savings, when homebuyers roll the $800 cost into a 30-year home mortgage at today's 5 percent interest rate, "For about $5 a month they can take a car off the road each year. It is a pretty cool thing to think about," LeMessurier said.
In Europe, similar roofs have been used in homebuilding for about five years, but KB Home is the first to use them in the U.S. Boral Roofing acquired the license to produce the tiles for the North America market from Monier, a company in Germany, Renowden said.
Usage in other industries
The technology is used in other industries, with Alcoa Architectural Products announcing just last week that they've created an aluminum architectural panel that not only cleans itself but also the air around it. The Alcoa panels also reduce nitrogen oxides in the air, similar to the Boral Roofing tile. The Alcoa panels are produced by Japanese manufacturer TOTO, Renowden said.
Other smog-fighting products available include ceiling tiles that remove formaldehyde, which is linked to health problems. These tiles are produced by Armstrong Ceiling & Wall Systems.
And Florida-based Zevoteck is producing an energy-efficient compact florescent light bulb called the Ionic Bulb that includes an air purifier to eliminate allergens from the air.
Renowden said the desire for products to help purify the air, such as the tiles, is a growing market.
"It's increasing. At the moment the tiles are mostly going onto model homes as it's quite new to the market and KB being the leaders in innvoation in the building industry were the first to apply it," he said. It's starting to gain momentum."
Teena Hammond Teena Hammond has published more than 2,000 articles in People and W magazines, Women's Wear Daily, and in dozens of newspapers and books. She also wrote a home improvement, remodeling and decor column that ran in Gannett newspapers nationwide. She's interested in all things green and would love to hear from you with your story ideas.