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HVAC Coil Corrosion Causes and Effects 

You would think that since San Antonio is well away from the coast with its salt air, you don’t have to worry about HVAC coil corrosion. While our location can make the outdoor unit coil less prone to rusting out, corrosion can still cause adverse effects on your indoor coil, so it’s vital to understand why it occurs.

What Causes Coil Corrosion?

Corrosion of an indoor HVAC coil is typically caused by volatile organic compounds (VOCs) in a home’s air supply. These VOCs off gas from building materials, pressed wood components in furniture, textiles, and numerous household and cleaning products. While it’s well known that VOCs degrade indoor air quality, they also oxidize into corrosive acetic or formic acid on the surface of an HVAC coil. Over time, these acids eat away at the metal causing tiny pinholes.

Symptoms of a Corroded Coil

The first signs of coil deterioration may be a decline in your HVAC system’s efficiency and output. You’ll likely find it more difficult to maintain a comfortable temperature, and see an increase in your energy bills. The underlying reason for this decline is a slow leak of refrigerant through tiny holes developing in the coil.

How to Prevent Corrosion

If you call in a professional to diagnose why your HVAC system’s efficiency is dropping and they find that it’s leaking refrigerant due to corrosion, your only options are a costly coil or equipment replacement. Before this happens, it’s wise to take steps to prevent corrosion:

  • Schedule regular professional HVAC maintenance. Make sure that the service includes cleaning the coil to neutralize acid buildup that erodes the metal.
  • Introduce cleaner outdoor air. You can do this naturally by opening windows, by using exhaust fans in the bathrooms and kitchen routinely, or investing in a mechanical ventilation system like an energy recovery ventilator (ERV).
  • Install a whole-house air cleaner on your HVAC system. A knowledgeable HVAC pro can advise you on the best type of air cleaner for eliminating VOCs.

For personalized advice about preventing HVAC coil corrosion in your San Antonio home, contact us today at Beyer Boys.

Our goal is to help educate our customers in the greater San Antonio, Texas area about energy and home comfort issues (specific to HVAC systems).