Mold in your AC system and ducts can pose many issues in your home. Understanding how mold gets there and what you can do about it is important.
Causes of Mold In Ducts
Mold grows in AC ducts for two reasons -- moisture and spores. For this reason, mold is most often a problem at the beginning and end of the cooling season, when the air is more moist. Mold issues often reduce during the summer in dry areas as the air dries out and mold goes dormant. If mold persists through summer and the weather is dry, then there may be an issue with drainage and condensation in the AC itself, which is causing mold growth to continue.
Mold spores get into the ducts via the air, but they are usually harmless until activated by moisture. Often, the mold originates in the outdoor unit or fan assembly since this is most exposed to environmental conditions. Mold can also grow in the filter or filter housing. Once mold is in the system, it can take hold in the ducts themselves and begin growing there.
Concerns From Mold Growth
The main concern with mold is your and your family's health. Some people are very sensitive to mold, so even a small amount can lead to respiratory problems, itchy eyes, skin irritation, or other allergy-like symptoms. Over time, exposure to mold spores can make it difficult for sensitive people to get restful sleep, so more severe health problems can ensue. With enough mold, even those that aren't normally sensitive can experience some negative health effects.
Mold can also be bad for your AC system. Too much moisture in the system can lead to rust and corrosion. If moisture is getting into the system, the problem needs to be remedied. Even if moisture levels aren't alarming initially, heavy mold growth can end up retaining excess moisture so it doesn't dry promptly, thus leading to moisture damage.
Repair and Cleaning
Repair begins with determining the cause of the moisture unless it is just normal seasonal humidity. A full inspection and tune-up of the AC system is needed. Then, have your AC unit cleaned out so that any existing dirt and mold can be removed and you can begin fresh. This includes replacing the filter and cleaning out the filter housing.
Cleaning the AC won't remove the mold and spores that are now in your ducts, though. For this, you will need to have the ducts completely cleaned by a professional. If you live in a damp or humid climate, it's a good idea to have the ducts cleaned annually.
Contact an air conditioner duct cleaning service if you are concerned about mold in your vents and ductwork.