Is Coil Corrosion Impacting Your HVAC System?

Coil corrosion is responsible for around 40 percent of all equipment failures in commercial facilities, making it one of the most expensive problems associated with your HVAC equipment. Coil corrosion starts small, but if left unchecked can quickly escalate, leading to coil replacement, or even requiring the entire system to be replaced.

Coil corrosion isn’t something that only happens with old equipment. In certain situations, you can find corrosion occurring as early as a few weeks after installation. It comes in two forms: pitting or formicary.

Pitting corrosion is caused by exposure to fluoride within the water supply, or through chloride found in a variety of products such as detergents and cleaners.  As ions from fluoride or chloride are transported into the system and make their way across the coils and condensate, the ions attack and begin pitting the metal. Over time pinholes are created, allowing refrigerant to leak.

Formicary corrosion is caused through access to acids present in a wide variety of products including cleaning solvents, adhesives, paints, plywood, and so on. Formicary corrosion is often referred to as ants nest corrosion because it tunnels within the tubing in a similar fashion to the way ants create their nests. Over time, the pinholes form in the coils, which lead to refrigerant leaks.  

While coil manufacturing companies are aware of the problem and are applying coatings prior to sale, there are a variety of companies that make aftermarket coatings that you can use to reduce corrosion on older systems already in place.

When coils are damaged, it has a variety of consequences on your overall HVAC system.

It starts with requiring your system to run harder to produce the same results. If the coils aren’t producing the required heat source, the compressor will work harder to create the desired results. This increases power usage, lowers the cooling capacity, and causes more stress on all parts of the system. More stress brings on more maintenance. And if the system isn’t producing the right air temperatures, it’s also creating a less than comfortable environment throughout your facility.

Whether coils are coated or not, the best way to combat corrosion and stop it before it occurs is through continuous maintenance. Cleaning coils at least twice per year will clear away any mineral deposits and keep them safe from accumulating corrosive materials. The earlier you catch it, the easier it is to stop it before it impacts your efficiency, and begins degrading your system.

How are you combating coil corrosion?