They are found in numerous hospitals, hotel rooms, schools, and offices. They are small air-handling units paired with chilled-water and hot-water coils, with a fan to circulate heated or chilled air.

Bob Haydu knows his coils. He has spent 35 years in the service industry and in management. He has a BA, an MBA, and has done special studies in corrosion, coatings, and coating applications. And, he ...