Coating System Extends Life of Corroding Air Supply Units by 10 Years

An automaker found a way to stretch the life of rooftop air supply units that were rusting, rather than replacing them right away. The equipment, made of galvanized steel, had started corroding after years of exposure to moisture and other elements. Instead of swapping out more than 100 units, the company had them treated with a three-step coating process: a rust-converting primer on spots where corrosion had already set in, an adhesion primer on steel that was still in good shape, and a final waterproof epoxy topcoat.

The treatment is reported to have added about 10 years of service life to the units, letting the automaker put off a costly replacement project.

This is an industrial case study, not a residential product, so it doesn't translate into a rebate or purchase for your house. But the underlying idea applies to home equipment too: rooftop or outdoor metal components, like ductwork, vents, or an outdoor condenser, can corrode over time from moisture and weather exposure. Catching rust early and treating it, rather than waiting until it fails, can sometimes delay the need for full replacement. If you notice corrosion on metal HVAC parts at your own home, it's worth having it looked at sooner rather than later, since early treatment tends to leave more options open than waiting until the damage is severe.