No Spores Indoors: What You Need To Know About Mold In Your Central Air

18 May 2015
 Categories: , Articles


A common problem with household air conditioning systems is the development of mold. Since your air conditioner sends cool air throughout your home, that means any mold growing in it will be distributed through your home as well. The best way to keep mold at bay is to clean and service the air conditioner regularly. Here is some helpful information about what can cause mold in your air conditioner, how to spot it and what to do about it.

Causes of Mold in Your Central Air

Central air conditioning systems create a prime environment for mold to grow. There are two key factors that contribute to mold growth in central air systems.

  • Condensation: When the air in your house is warm and humid, the sharp change in temperatures caused by the cold air ducts will cause condensation inside your air conditioning system. In most cases, that condensation will evaporate as soon as the system shuts down. Sometimes, though, the air is too humid and the moisture can't dissipate at all. The residual dampness encourages mold development.
  • Dirt and Dust: Air conditioning systems gather a lot of dust, pollen and dirt particles. When these things settle inside the air conditioner, they serve as a source of food for mold to thrive. When you combine this food source with the moisture in the system, you're creating a balanced environment to support mold growth.

Signs of Mold in Your Central Air

Knowing what to watch for is the first step toward dealing with mold growth in your air conditioner. Here's a look at a few things that indicate you may have a mold problem.

  • Musty Odors: Mold growth in your air conditioner will cause a musty, mildew-like smell in your house. If you notice the smell increasing when the air conditioner comes on, that's a sure sign you may have mold issues.
  • Visible Mold Spores: Inspect the air ducts, drip pans, air intake vents and cooling coils for any visible mold spores. These are the most common spaces where mold will grow in air conditioning systems.

If you don't see mold spores inside the unit but you're certain that you smell it, talk with an HVAC service technician about a thorough cleaning and service on the whole system. You may be detecting early signs of mold that you can eliminate before it becomes visible.

Treatments for Mold in Your Central Air

When mold has started developing in your air conditioner, it can take some effort to get rid of. There are many small cracks, crevices and spaces that can be difficult to clean. Here are some tips to help you deal with mild mold growth, though you should call an HVAC service technician to deal with more elaborate problems.

  1. Use a Cleaning Solution: Start with a mixture of a teaspoon or two of dish detergent in a cup of water. Also, create a solution with a half-cup of bleach in a gallon of water to use for disinfection afterward.  
  2. Scrub the Area: Spray the surface with the detergent solution. Use a brush or clean rag to scrub the area. Once finished, spray the bleach solution on the area and let it sit for a few minutes to disinfect the space. Then, wipe the whole area clean with some damp paper towels. You may need to repeat the process a few times to get rid of all of the mold. Finish the process with one final application of dish detergent solution to get rid of any residue.

With the tips presented here, you can identify and deal with the potential mold growth in your air conditioner. If you're not comfortable doing the work on your own, most air conditioning service centers will inspect your central air a few times a year to help you prevent mold development. Visit to learn more about the services offered by local HVAC companies.