Causes of Corrosion The evaporator coils developed pits and subsequent corrosion. Copper corrosion also occurs when it’s exposed to acetic or formic acids found in household products like adhesives, cleaning solvents, paint and plywood. It shows up as blue or black deposits on the coils.

What causes AC coils to corrode?

The indoor evaporator coil corrodes due to airborne volatile organic compounds (VOCs) that are off-gassed by building materials, pressed-wood furniture components, as well as textiles, fabrics, and various everyday household products.

How do you prevent AC coils from corroding?





The best way for a building owner to prevent coil corrosion is to apply a protective coating to the coil. Coating types include polyurethanes, epoxies, fluoropolymers and silanes. Each coating type has its own distinct advantages and disadvantages.

What happens when AC coils rust?

Corroded coils can lead to leaking refrigerant and a loss of cooling power, and they’re one of the top causes of needing to have a coil replacement. Or, in some cases, replacing the whole air conditioner. Catching the problem early makes it more likely you can avoid a bigger, more costly repair.

Is it normal for evaporator coil to rust?

Rust will be a normal sign of age of the coil. However, too much rust on a young coil can mean that the coil has been leaking and freezing over. As a result, the added moisture from the ice has sped up the rusting of the support parts.

How long should AC coil last?

10 to 15 years





For an evaporator coil to live out the fullest extent of its life, the AC unit must be regularly maintained. If proper maintenance is regularly performed, then the evaporator coils should last 10 to 15 years, which is the ideal lifetime for an evaporator coil and comparable to the lifespan of an AC unit.

How much does it cost to replace an air conditioner coil?

Condenser Coil Costs

Coil Capacity Part Only Installation Cost
1.5-2.0 ton $575 – $800 $475 – $650
2.5 ton $625 – $975 $535 – $750
3.0 ton $735 – $1,055 $600 – $835
3.5 ton $775 – $1,025 $775 – $985

How do I stop my AC condenser from rusting?

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What are the two common types of coil corrosion?

The two most common forms of coil corrosion are pitting and formicary. These two corrosive processes can occur in as little as a few weeks after installation. More typically, corrosion will begin appearing within a one-to-four-year period.

Why do condenser coils fail?



The reason for this is most condenser coils have fin spacing of 12-20 fins/inch. With fins that tight together, the coil can and will act like a filter. And when the coil is clogged up, the performance suffers greatly.

Can you use a rusted air conditioner?

The presence of rust can have a serious impact on your air conditioner’s performance and reliability. Not only is a rusty air conditioner a cosmetic eyesore, but the structural damage it causes can damage your system in ways you wouldn’t expect.

Is it normal for AC to rust?

Rust forms on your air conditioner primarily due to the accumulation of water or condensation of moisture on the A/C components. Some of the parts that are likely to be affected include the condenser coils, evaporator coils, drain pan, compressors, fan blades, and ductwork.

Can AC coils be repaired?



If you’ve got a damaged air conditioner coil, a number of things can happen. If it’s early stages and the coil is simply bent or broken, then a repair might be the most cost- and time-effective route to take. However, it’s fairly common for a coil to be damaged not due to a bump or bend, but due to corrosion.

How do I know if my AC coil is bad?

If you have your air conditioning system turned on but warm air is exiting your vents, it could be a sign that your evaporator coil is not working properly. This happens when your AC system is otherwise functioning as it should, but your evaporator coil is not effectively cooling the circulating air.

How often do AC coils need to be cleaned?

Air conditioning coil corrosion protection treatment & chemical … ·

What are the two common types of coil corrosion?

The two most common forms of coil corrosion are pitting and formicary. These two corrosive processes can occur in as little as a few weeks after installation. More typically, corrosion will begin appearing within a one-to-four-year period.

Why do condenser coils fail?



The reason for this is most condenser coils have fin spacing of 12-20 fins/inch. With fins that tight together, the coil can and will act like a filter. And when the coil is clogged up, the performance suffers greatly.

Why does corrosion occur and how do you prevent it HVAC?

Two principal dissolved gases, oxygen and carbon dioxide, cause the primary corrosion problems in heating and cooling systems. Both gases, if not removed or chemically treated, will contribute to corrosion within water systems.

What causes formicary corrosion?

Formicary corrosion is caused by a chemical reaction requiring three parts: oxygen, water, and an organic acid. If any of the three parts are removed there can’t be any further formicary corrosion. Formicary corrosion only occurs in copper based alloys and HVAC coils are often made of copper.

How do you protect a cooling coil?

Maintain Efficiency



Coating your coils with UV-inhibiting coating protects them from the sun. The sun UV rays degrade the coils when exposed for long periods. This may reduce their efficiency and or even the breakdown of the entire system.

Which type of corrosion occurs specific to copper coils in outdoor AC units?



Pitting corrosion happens when the coil is exposed to water, chemicals or detergents that contain chloride or fluoride. This creates cavities or ‘pits’ in the metal surface of the coil, increasing the potential for leakage.

What are air conditioner coils made of?

The evaporator coil is inside or near the air handler where the blower fan is. Evaporator coils are made from copper, steel, or aluminum because these metals conduct heat easily. Most residential AC evaporators consist of tubes bent into U-shapes and set into panels.

How do I protect my outside AC unit from rust?

The best way to prevent rust is a proactive approach. In some cases, you can purchase an air conditioner that’s made specifically for coastal areas and contains a rust-prohibitive coating. If you can’t find one of these, then you can always apply the coating yourself or call us to do the work.

Can aluminum AC coil be repaired?

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Quote from Youtube video: Save you and your customer valuable time save money by repairing not replacing expensive aluminum evaporator coils.