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Mold On Your A/C Evaporator Coils? Here's How To Deal With It

If you've noticed your A/C isn't as cool as it once was, it might be due to unforeseen mold growth. Mold is a menace that not only poses a health risk, but also degrades the overall performance of your HVAC system. The following deals with the underlying factors that promote mold growth, as well as ways you can put an end to it.

How Mold Growth Takes Hold

There's nothing mold and mildew loves more than a nice, dark and damp place to flourish. Unfortunately, the environment inside your HVAC system's indoor cabinet fits those requirements to a tee. As your A/C system operates, the evaporator coil is hard at work extracting heat from the air flow it receives via the blower fan and return air inlet. However, this process creates condensate, which drips off the evaporator coil and onto the drain pan below.

All this moisture in a relatively damp and clammy environment offers plenty of opportunity for mold spores to take root and create explosive growth. The end result is an evaporator coil that's caked with slimy mold and mildew.

Blocked evaporator coils are no good for cooling, since it's nearly impossible for air to flow through the clogged coil fins. There's also a good chance that mold and mildew can clog up the condensate drain line, which causes flooding and adds to the excess moisture problem.

Taking Care of Business

The first order of business involves getting rid of the mold growth. There are several methods you can use, each with its own benefits and drawbacks:

  • Compressed air – Many HVAC technicians use this method to clean off mold without making physical contact with the coil fins. However, this can spread dirt, debris and mold spores to other areas of the indoor cabinet.
  • Self-rinsing foam cleaner – Not only does it save you the hassle of bringing a brush or compressed air in contact with the delicate coil fins, but it also saves you the trouble of rinsing the evaporator coil. As the foam breaks down into a liquid, it'll also break down most, if not all of the mold and mildew on the coil. However, you may need multiple applications to break down stubborn mold.
  • Soft brushes – This method is effective for stubborn mold removal, although care should be exercised to not inadvertently bend the evaporator coil fins.

After cleaning the evaporator coil, the next step involves cleaning the condensate drain line and drain pan. In most cases, the line may be clogged with mildew growth, resulting in a drain pan that's prone to overflowing with condensate:

  • Use a wet/dry shop vacuum to remove any standing water in the condensate drain as well as any that's spilled onto the floor.
  • Break up any clogs present in the line with a small plumbing snake. You can also use your vacuum to suck out the clog.
  • Thoroughly clean the condensate drain pan with a disinfectant cleaner. Afterwards, pour a cup of household bleach into the condensate drain line to kill any remaining mold or mildew.

Preventative Measures

It's important to look at mold as not a problem in of itself, but as a symptom of an underlying problem. For example, excess humidity can easily spur explosive mold growth. Keeping your home's relative humidity below the 60 percent threshold not only keeps your home comfortable, but it also curtails mold growth to a significant degree.

You should also take steps to keep your HVAC system's ductwork clean. This includes having a professional from a site like http://www.perryheatingandcooling.com carefully vacuum the ducts and inspect them for gaps, cracks and other damage that could allow dust to get through. Changing your furnace air filter on a monthly basis also helps cut down on dust, mold spores and other airborne debris that could contribute to mold growth.

Another good way to prevent mold from coming back with a vengeance is with the help of an ultraviolet (UV) lamp. UV lamps are an indispensable tool for curtailing mold growth within the evaporator coil cabinet of your HVAC system. These lamps generate the same UV rays as natural sunlight, which helps break down the molecular bonds that keep mold and a variety of other bacteria together.