Mold in Air Ducts? How Did It Get There?

Boston Mold Removal by Aspen Air Duct Cleaning

Mold in your home or business can not only cause a foul smell, but it can also harm your indoor air quality and negatively affect your health. Aspen Air Duct Cleaning cleans air ducts and removes mold in the Greater Boston area. You may be asking questions like:

How does mold grow in ductwork?

How can I keep mold from entering my home or business?

What is the best way to clean mold?

In this article, we'll discuss all of these questions and provide an overview of what causes mold growth, how to spot mold before you can see it, and how to prevent mold in your home or business.

Signs of Mold in Ductwork

If you think you might have a mold problem in your air ducts, look for signs of mold. Mold is not always visible to the naked eye, but sometimes it can leave stains on the walls or ceiling around an HVAC unit. You may also notice discoloration or a musty odor coming from your vents. If this sounds familiar, don't worry—you're not losing your mind. Now that you know what to look for, have any visible mold removed and cleaned by a professional immediately!

  • Musty odors
  • Dust build-up on vents
  • Allergy symptoms
  • Visible mold growth

The Obvious Things That Cause Mold

Mold Education in Boston with Aspen Air Duct Cleaning

Mold is attracted to many of the same things that make humans happy: moisture and warm, humid environments. If you're living in your home and the air ducts are not well-ventilated, it's easy for mold to form in them. This can happen if water leaks into the system or if there is poor ventilation overall.

  • Moisture
  • Heat

If you notice a musty smell coming from your vents, this could be a sign of mold growth in them. The smell will likely be strongest when you turn on a fan or heater that blows air through those vents—but it'll also linger when there aren't any fans running too.

How Can I Keep My Ducts Clean?

Keeping your home’s humidity low is a great way to prevent mold from growing in the air ducts. A good rule of thumb is to keep the humidity below 50 percent by running fans, dehumidifiers, and air conditioners when needed.

While you may also want to consider how hot or cold it gets in your home during different times of the year, an ideal temperature range for most homes is between 60-70 degrees Fahrenheit during winter months, and between 75-80 degrees Fahrenheit during summer months. This will help maintain a comfortable level of airflow throughout the house while keeping any unwanted moisture out of your ducts.

As far as circulation goes, if there are any rooms in your house that don't get much traffic (like basements), try turning on fans or plugging them into timers so they run periodically throughout the day to keep air moving through those areas too!

Keep The Humidity Out of Your Home

As we mentioned, humidity can be a big contributor to the growth of mold in your air ducts when moisture and heat combine in the ductwork. To keep humidity levels down in your home or business:

  • Use a dehumidifier
  • Use a humidistat
  • Use disinfectants

Humidity is the breeding ground for mold and having a plan to combat a humid environment is important to stop the initial cause of mold. You could clean mold and it could come back if you don’t resolve the underlying issue.


There are a few things that you can do to keep your air ducts clean. The first thing is to keep the humidity at a reasonable level in your home so there is no condensation on the inside of your ductwork. You also want to make sure that if there is any moisture present in your attic or crawl space, it gets dried out as quickly as possible before mold starts growing. If you find mold growing inside of your ductwork, then by all means get it taken care of immediately! Otherwise, be sure not to disturb the area until after professionals have cleaned up and removed all traces of mold spores from around them.

Mold Removal & Air Duct Cleaning in the Greater Boston Area

If you have visible mold, musty smells, or an accumulation of black dust on your vents and are interested in air duct cleaning and mold removal for your home or business, Aspen Air Duct Cleaning is ready to help. You can request an estimate or request service here. Feel free to call us to discuss your specific situation at (978) 681-5024.