Signs Of Mold Growth In Air Ducts

Your home's air ducts are warm, dark, and tucked out of the way, making them the ideal breeding ground for mold and mildew growth. Mold growth in your air ducts can have all sorts of implications for the rest of your home and even your personal health, so it's necessary to know the warning signs of mold growth within your HVAC system so that you can contact a professional early to clean the air ducts before it becomes a serious issue.

Odd Smells

If you notice that there is a strange smell that is carried with your central heating or air conditioning air flow, you may have mold growth in your air ducts. Mold tends to have an earthy, moist smell, and it can be hard to miss depending on how widespread the growth is and what type of mold it is. As a general rule of thumb, you can test to see if the smell is coming from your air ducts by turning off your central air or heating unit, and then seeing if the smell goes away. If it does, your air ducts are most likely the problem, but if not, you should look around the room that the smell is in to locate the source.


Another good indication of mold and mildew growth in your air ducts is if you find any sort of moisture or signs of water damage around your air vents. Water damage can take the form of discoloration around the vents or even warping and bubbling of wallpaper, flooring, paint, or any adjacent material. While this can often be attributed to an issue with insulation or plumbing, the point remains that any sort of water damage in your home can contribute to mold and mildew growth, and so it is worth getting in touch with an HVAC professional to take a look within your ducts to see what condition they are in.


The last main indicator of mold growth in your air ducts is if you or a member of your family has experienced any sort of aggravation of allergies or respiratory conditions, especially if it is out of season for those symptoms to show up. Sometimes this can be a fluke, but consistent allergy problems can point to mold spores in your home's air supply, usually coming from your air ducts, and you should have them cleaned out as soon as possible to protect your health.