What Causes a Musty Smell from AC?
Sometimes, something awful hits the air when you turn on your air conditioning. While unpleasant odors are never welcome indoors, there’s something particularly worrying when it comes from inside your ducts and vents.
One of the main concerns is that you can’t see where the smell is coming from. If your home is like most in the U.S., you have central cooling with ducts that trace through your walls and floors into each room.
It can be tricky to find where that smell is coming from and what’s causing it.
Most people attempt to deal with musty smells from air conditioning by cleaning vents, spraying disinfectant into ducts, or leaving the AC off.
However, there are reasons why your air conditioning smells musty, and knowing the causes can help you fix issues and avoid nasty odors at home or in the workplace.
Here are some of the main reasons why your AC smells musty.
Mold Growth Causes Musty Smells
Mold is by far the most significant reason for musty smells coming from your ducts. When moisture gets inside your HVAC system, it loves to hide against your duct walls in dark places where it can grow uninterrupted.
Depending on where you live, mold can be especially pernicious. It grows very quickly in humid areas, places that are hot in the summer, and where it’s dark.
If your home or commercial property is damp, you should be alert for mold growth.
Mold smells musty like something is wet or rotten in the house. It’s almost like you can taste the air you’re breathing. Musty smells are usually most noticeable when you first walk into the house.
It’s normal for people living in a house not to notice musty smells because they are always there. If someone you know walks in and tells you it smells musty, take the problem seriously.
A musty smell indicates bacteria growth build-up inside your house.
Other Signs of Mold Growth
It’s typically impossible for the average homeowner to look deep inside their ducts to look for mold, so how can they be sure?
Air duct cleaning services use specialized tools like video camera equipment to get visual confirmation of mold growth. It’s unlikely you have something like that at home, but there are other ways you can spot mold growth and know whether you need professional duct cleaning.
Here are some other signs of mold growth besides musty smells:
Mold in other areas - If you spot mold on your walls, floors, or ceilings, or black spots on your vents, it’s possible you have mold in your ducts. Mold in your ducts is likely, especially if you don’t see any other obvious cause, like water damage or leaks in the basement.
Allergies - Are your allergies spiking whenever you’re at home, and you don’t know why? One of the main culprits of at-home allergies is mold. In addition to mold, enough dust and pet dander in your ducts can trigger musty smells.
Other Health Issues - Pay attention to your body. Do your eyes water at home? Do you have trouble breathing or sleeping? Health problems may be caused by mold growing in your vents.
These are just some of the signs of potential mold growth in ducts.
Is Mold in Air Conditioners Dangerous to Health?
Mold inside your air conditioning and ducts can spread across your house and into the air you breathe.
Mold is a significant health risk to young people, pets, older folks, and people with sensitive immune systems. In addition, people with asthma or sensitive allergies are also at higher risk due to mold exposure.
Mold causes allergies, sinus problems, coughing, wheezing, watery eyes, sleep problems, and other health issues.
How to Get Rid of Mold and Musty Smells from AC
One of the first things you should do is confirm that the smell is coming from your air conditioning.
Turn the AC off, let it rest, then turn it on again. If the smell is only noticeable when the AC is on, then it’s a good bet the ducts or your appliance is the cause.
However, your AC can sometimes smell musty because it’s been a while since you turned it on. After a wet winter, for example, there could still be some moisture in your ducts.
It may take time for your air conditioning system to blow everything out. When you’re first starting to use your AC in the new year, for example, leave it on for several hours each time, and see whether that helps reduce the smell.
If the musty smell doesn’t fade or disappear, you’ve possibly got something inside your ducts that’s causing the problems.
Duct issues are likely, especially if your air conditioning is working properly. On the other hand, you may have appliance issues that are causing the smell due to leaks, excess condensations, or other concerns.
Can Professional Air Duct Cleaning Get Rid of Mold?
Yes, professional air duct cleaning services can find and eliminate mold inside your ducts.
Call a reputable service in your area if you can’t seem to get rid of musty smells in the air whenever you turn on your air conditioning.
Here’s a basic overview of what they can do to help:
Inspect your ducts - Air duct cleaning companies use video camera inspections to look inside your ducts to find any mold or other causes of musty smells.
Vacuum - They use specialized vacuums that suck out mold particles, dust, hair, pollen, and other irritants.
Scrub brushes - The vacuums typically have strong brushes attached to their heads to clean the walls of your ducts as they go. The cleaning does a great job of preventing future mold growth in your system.
Anti-mold UV lights - Some companies offer UV light installation that stops mold from growing again. These lights sit inside your ducts and kill mold particles before they multiply.
Most experienced duct cleaning technicians know the smell of moldy or musty air conditioning systems. Find one near you and give them a call for a visit. There’s a good chance they’ll quickly get to the bottom of your odor issues and eliminate unwelcome smells inside.