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September is Mold Awareness Month. Do You Know the Signs that Mold May be Lurking in Your Air Ducts?

Posted on 09/21/2022

While we all know how dust can negatively affect our health, mold is a whole different animal! Not only can mold exacerbate allergies and respiratory problems, but it can also spread quickly throughout your home.

It’s no secret that mold thrives in damp, dark places like bathrooms and basements, but did you know it can also grow in your home’s ductwork? Since air ducts tend to be out-of-sight, out-of-mind, it’s common for mold in the vents to go undetected, and mold in an air duct system can be a serious issue since any time the heating or cooling system is running, all those mold spores are spread throughout your home multiple times a day. 

September is Mold Awareness Month, so the Breathing Clean team here at NADCA is here to educate homeowners on everything mold, including ways to spot mold in your home, common symptoms of mold allergies, and what to do about mold in your ductwork.

Signs of Mold in Your Home

To keep your home and family healthy and breathing clean, it’s important to know the signs of mold. If you recognize any of the following things in your home, mold may be lurking somewhere:

  • Water. Although mold and its spores are everywhere, active mold growth requires moisture. Whether on visible surfaces or hiding behind drywall, in attics, or under carpets, indoor mold grows in the presence of excessive dampness or water. 
  • Humidity and Condensation. Humidity or water vapor in the air can sometimes supply enough moisture for mold to thrive and grow. If your home feels humid, or you notice an abundance of condensation, you’ve got a prime environment for mold. 
  • Odor. Is there a strange, earthy smell in your home that won’t go away, no matter how much air freshener you spray? Mold may be at the root of the issue. Microbial Volatile Organic Compounds (MVOCs) are gases produced by mold, and that musty odor you smell from mold is caused by MVOCs. Did you know that while air fresheners and candles may smell nice initially, they too, add Volatile Organic Compounds (VOCs) to your indoor air?
  • Health Problems. Some people may not be affected by mold at all, but others can have an allergic reaction to it. In fact, being exposed to indoor air polluted with mold can cause upper respiratory tract infections and can worsen symptoms in people who have asthma. These illnesses can be extremely dangerous—especially for children and the elderly, or anyone with a weakened immune system.

Signs of Mold in Air Ducts

Your heating and cooling system can develop condensation that leads to the growth of mold in your ductwork (especially if you live in a humid climate). You may spot mold in and around your air vent covers, but unfortunately, many components of your air conditioning and heating system aren’t easily accessible or visible, so mold in your air ducts is especially difficult to detect. However, while mold can be difficult to see, it usually presents itself in the form of a musty odor.

Even if you don't see mold in your air vents, it doesn't mean there isn't mold deeper in your air ducts. Undetected mold in a home can be incredibly harmful from an indoor air quality standpoint. It’s important to be aware of a few telltale signs that there could be mold lurking in your home’s air ducts:

  • A strong, musty mildew smell throughout your home, not just one room
  • Evidence of mold growing near the intake vents or around the air ducts
  • People living in the home frequently experience symptoms like headaches or wheezing (especially when in the home)

Symptoms of Mold Allergies

Mold allergy symptoms are very similar to the symptoms of other allergies, and can include:

  • sneezing
  • runny or stuffy nose
  • itchy throat or ears
  • hives
  • swollen or itchy eyes
  • coughing, wheezing, or difficulty breathing

If you suffer from asthma or other respiratory problems, the presence of mold in your home can be even more bothersome. Exposure to indoor mold has been known to aggravate asthma symptoms in sensitive individuals, such as children and the elderly. Length of exposure may also dictate the seriousness and duration of mold allergy symptoms. 

If your home or family is showing symptoms that point to the presence of mold, it’s important to act quickly! Addressing issues immediately will prevent the spread of spores and lessen the severity of symptoms that individuals living in the home may be dealing with.

Mold Cleaning and Prevention

In general, prevention is key when it comes to dealing with mold. The CDC recommends using an air conditioner or dehumidifier to keep humidity levels in your home lower than 50 percent, ensuring you have sufficient ventilation, optimizing settings on your thermostat, using mold inhibitors in your paints, and cleaning your bathroom with mold-killing products. Keep in mind that if the conditions causing mold in the first place aren’t corrected, mold growth can return.

It is also a good idea to schedule periodic air duct inspections to be sure that mold and other hidden hazards aren’t lurking in your ductwork. When you decide it’s time for air duct cleaning, make sure you choose a qualified contractor to ensure the job is done right. NADCA makes it really simple for homeowners to find an air duct cleaning professional. All it takes is a zip code to search our online directory to find a NADCA member in your area; look for a Certified Ventilation Inspector (CVI) to do the job right. 

Should suspected mold be found in your HVAC system, a NADCA member can recommend the best approach for properly testing and then eliminating it (and preventing future reoccurrences). 

Click Here to Find a NADCA-Certified Professional Near You!