HVAC systems are built to withstand years of use but they’re not invulnerable. Coil corrosion is one of the few problems that will undermine its useful life. Under normal conditions, the two copper coils HVAC systems use don’t react with their environments and stay intact. Under certain circumstances, however, they will oxidize and pit, eventually weakening.
Where the Coils Are
The air handler houses the evaporator coil that absorbs the heat in your home’s air and sends it out to the condensing coil, which sits in the outdoor condenser. The coils hold the refrigerant and are essential to the operation of air conditioners and heat pumps.
How Corrosion Happens
More often than not, the corrosion occurs as a chemical reaction with the coil from volatile organic compounds (VOCs) that contain fluoride, chloride, or acetic or formic acids. Product like plywood, cleaning solvents, detergents, adhesives, and some carpeting and fabrics contain these acids. Should they condense on the coil, tiny leaks can form.Excessive amounts of dust can also cause the coils to leak, especially outdoors, although it can happen in the evaporator coil. Clean air filters and annual professional maintenance prevent most coil leaks.
What Coil Leaks Do
The refrigerant in HVAC systems undergoes phase changes from a gas to a liquid and back again. Since the gas is under pressure, it will flow easily through the leaks.
Signs of a Coil Leak
An air conditioner or heat pump that isn’t working properly may have inadequate refrigerant brought on by coil corrosion. When the HVAC technician tests the system, he will check the refrigerant pressure. If it’s low, he will look for leaks.
Repair or Replace
The technician may be able to seal the leak temporarily, but eventually you’ll have to replace the coil or the entire HVAC system. If a coil isn’t available or the system out of warranty, it may be more cost effective to replace the entire system.
The best way to avoid coil corrosion is to keep your system clean and professionally maintained. For more information, contact Air Assurance, providing HVAC services for Broken Arrow homeowners.
Our goal is to help educate our customers in the Tulsa and Broken Arrow, Oklahoma area about energy and home comfort issues (specific to HVAC systems). For more information about HVAC systems and other HVAC topics, call us at 918-217-8273.