Innovative Air Technologies applications

All materials corrode, which is to say every substance eventually changes from one form to another through chemical reactions. Many of these reactions, especially those which depend on oxygen, are catalyzed and accelerated by moisture. Dehumidifiers  are working to protect materials from more subtle and expensive forms of corrosion.

When cold surfaces are surrounded by moist air, water vapor will condense on the surface like “sweat” on a cold beer glass in summertime. This can lead to a surprising number of problems. For instance, consumers in a supermarket may not be able to see frozen foods in a refrigerated display case with a glass door. That may mean thousands of dollars in lost revenue. Alternately, condensation can form on hidden aircraft structural members as a plane descends from the cold upper atmosphere into moist environments, which can accelerate stress corrosion, shortening the life of the air frame. In both of these cases, dehumidifiers are installed to surround the cold surface with dry air.

Mold and fungus are present in almost all materials. They can survive without moisture, remaining dormant for decades, even centuries. But when moisture and a food source become available they will multiply rapidly. This moisture does not have to be  in liquid form. Microscopic organisms can use moisture present in solid materials because they need so little. Dehumidifiers prevent the moisture with dry air.

Virtually every substance has some affinity for moisture. Even plastic resins like nylon cans collect six to ten percent of their dry weight in water vapor. In many cases, this presents no problem. In others, moisture regain can affect critical dimensions just like thermal expansion, or make products that would otherwise flow freely stick together. The typical home salt shaker  illustrates this point: moisture regain on humid days clogs the shaker holes. On a dinner table, this may be a minor problem. But in packaging machinery, sticky products have major economic consequences. Desiccant dehumidifiers are effective in controlling humidity at low temperatures, and have been widely applied to prevent moisture regain.