Is Mold Growing On Your Air Conditioner's Evaporator Coils?

You rely on your air conditioner not only to control the temperature of your home but to deal with excess humidity too. Of course, the moisture sucked out of the air has to go somewhere, and it can create mold growth problems inside the outdoor unit. Watch out for mold growing on the evaporator coils and take care of it promptly to prevent the problem from spreading throughout your home.

Signs of Mold Growth

You might notice an increase in respiratory problems or a musty smell, but there's no way to know where the mold is growing with such vague symptoms. The only way to tell where the mold is in your system is to open the outdoor unit and check for visual confirmation. It's usually easier to rule out mold in tower first rather than starting with an inspection of the ductwork since the ducts can be tricky to access and quite long.

Causes of Moldy Coils

The evaporator coil is the part of the A/C that handles dehumidification because humid air flows over the coil while it's cooled by the refrigerant. Since this causes moisture to condense on the surface, there's always a source of moisture for fueling mold growth as long as the A/C is running. Combine that with the tendency for the coil to get covered in dust and debris that feeds mold and it's no surprise that mold commonly grows on this part of the unit.

However, mold growth still indicates something's wrong in the air conditioning system. The water on the coil falls into a drain pan and then flows down a hose away from the house. If the drain is clogged, the pan will get moldy and the spores spread quickly to the coil above.

Fixes for Mold Problems

If you discover mold growing on the coils, it's best to leave the cleaning process to the professionals. They'll remove all the residue with a cleaning product that doesn't damage the coil. It's easy to accidentally bend or dent the coil with enthusiastic cleaning, so letting a professional handle it ensures you don't end up with a costly repair. You may need to follow up with further fixes like

  • Unclogging the drain pan by flushing the hose with a shop vacuum, vinegar, or hydrogen peroxide
  • Finding other mold growth in the home that is supplying the spores flowing into your A/C
  • Checking that the mold hasn't spread to the ducts
  • Changing your air filters more regularly
  • Upgrading to a filter that traps more dust and spores.

For more information or assistance with your air conditioner repair job, contact an HVAC contractor near you.