Auto A/C Evaporator Coil

Are You Experiencing Auto A/C Evaporator Coil Leakage?

An auto A/C evaporator leakage can be very frustrating to deal with. These leaks cause the escape of refrigerant which compromises the efficiency of the cooling system. Getting the refrigerant recharged can be costly, and the substance itself is classified as an environmental hazard.


It should be noted that a certain amount of water dripping from the A/C’s evaporator coil is normal in most cases. The refrigerant within the coil will expand, which extracts heat from the air within the cabin which then makes the water condense. The liquid will drip from the coil onto the condensate pan where it will eventually leave the vehicle. If you find that your mechanic has to place new refrigerant into your vehicle yearly, this usually means that the coil has begun leaking excessively.

Why Evaporator Coils Are Susceptible To Leaks

Some of the A/C units that are installed within automobiles have evaporator coils that leak due to defects or improper installation. Many drivers will notice the leaks within a few months of installing the A/C and get it corrected by either re-soldering the joints or tightening the fittings. In normal A/C systems it will take years for leaks to appear, which usually results from wear.

Over time, formic acid will accumulate as a result of interactions among moisture, volatile chemicals and oxygen near the copper tubing’s surface. The formation of formic acid will become worse in the vicinity of chemical fumes. Coils today are also designed differently than how they were in the past.

For instance, many of the higher efficiency air conditioning systems now use thinner copper than previous models. Although this enhances the transfer of heat between the refrigerant and external air, it also means that the tubing corrodes faster and will begin leaking sooner than tubing which is thicker.

Changes have also been made to the refrigerant itself. R-410A, which is the refrigerant used in many new vehicles, is more eco-friendly than the older R-22. However, R-410A needs greater operational pressure for optimal performance. The increased pressure combined with rapid penetration from corrosion into the thinner coils makes leaks happen faster than was the case in previous models.

How To Avoid Leaky Evaporator Coils

The best way to avoid leaky evaporator coils is routine maintenance, at least once a year. When the coils are cleaned, this will delay leakage by reducing the accumulation of residue on coils which is corrosive. A number of A/C manufacturers are also switching from copper to aluminum, since it has greater corrosion resistance. You should also make sure your vehicle is not using VOCs (volatile organic.