By BUILDER Magazine Staff. Always dark and sometimes damp, HVAC ducts can breed mold, mildew, and a menagerie of nasty organisms ranging from Legionella to e-coli. If this happens to one of your buyers, guess who they're likely to blame?

Now the Middletown, Ohio-based AK Steel thinks it has a solution: self-cleaning ducts. This March, the EPA approved AK's new anti-microbial steel for use in heating, ventilating, and air conditioning (HVAC) systems. The steel is coated with an anti-microbial compound produced by AgION Technologies in Wakefield, Mass., and uses silver ions to control a range of microorganisms. "The ions are released at a slow and steady rate," explains Chuck Gerba, a professor of microbiology at the University of Arizona, "ensuring long-term protection."

To test AgION, AK is building what it calls "the nation's first anti-microbial home," an 11,000-square-foot test mansion in Simi Valley, Calif., that should be finished next spring. All ducts will use the new steel, as will doorknobs, handrails, faucets, and food preparation surfaces. Gerba will monitor the impact of anti-microbial ducts on the home's air quality.

Opulent test homes notwithstanding, AK is targeting the mass market. Electrolux Home Products will use the new steel on its Frigidaire brand appliances, and Alan McCoy, AK's vice president of public affairs, says the company is "talking with all major HVAC and appliance manufacturers." AK has also introduced a coating it can sell to small shops. McCoy says the coating should add just 15 percent to 25 percent to a typical HVAC system. For more information, go to