One way to prevent such problems is to use AgION coatings developed by AK Coatings, Middletown, Ohio (, on HVAC components. The inorganic coating, which can be pigmented or transparent, uses encapsulated silver ions to suppress microbe growth on carbon and stainless steel. Coated steel parts can be formed, bent, and drawn using conventional techniques. Coated parts can be cleaned with mild detergents and air dried. Abrasive cleaners, strong solvents, and acid-based cleaners can damage the coating.

The coating has been approved by the FDA for an additive in food-contact polymers, by the National Sanitation Foundation for product and food-zone applications, and by the EPA as an antimicrobial agent in HVAC systems. The UL certifies the coating is not a fire or smoke hazard. The coating also resists saltwater and humidity and works in a wide range of temperatures and pH levels.