How Often Should You Clean Your Air Ducts?

person using a vacuum to clean air duct in floor of home

Indoor air has been shown to be more polluted than outdoor air. So, it stands to reason your air ducts should be cleaned on some type of regular basis, right? Not so much. Air ducts have never been proven at fault for worse (or better) indoor air quality. In fact, when it comes to how often you should clean your air ducts, it’s only recommended if there’s visible mold growth, extreme amounts of dust and debris, or a pest infestation.

But First, What Are Air Ducts?

A part of your home’s HVAC system, air ducts are typically made of sheet metal or fiberglass. Their job? To serve as conduits for airflow in your house, be it cooled air from your air conditioning in the summer or heated air from your furnace or heat pump in the winter.

Maintaining indoor air quality by consistently recycling the air in your home, return ducts pull in air from various rooms, filter that air, and send it to the heating or cooling system. Then, the supply ducts push that air back out into your living spaces with help from a blower.

How Often Should You Clean Your Air Ducts?

There’s a lot of information about how often homeowners should clean their air ducts floating around online — some sources say once a year, some suggest once every three to five years, and others urge once every eight to 10 years. 

But the most reliable sources, the Environmental Protection Agency (EPA) and the National Air Duct Cleaners Association (NADCA), avoid recommending an arbitrary duct cleaning schedule for everyone, advising people to simply clean their air ducts as needed. 

Why? Every household lives under its own unique conditions. For some, it may be possible to go 10 years or longer without an air duct cleaning, while others (particularly those living with asthmatics, smokers, and pets) might need a cleaning much sooner. Below, we’ll get into a few more reasons you may need an air duct cleaning.

Pro Tip: A general rule of thumb is to have your air ducts inspected annually to make sure everything is working properly.

Signs Your Air Ducts Need Cleaning

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You Notice Significant, Visible Mold Growth

You may even catch a whiff of a musty smell. Since the same ductwork delivers both hot and cold air throughout your home, depending on the season, those varying temps may cause condensation, which, in turn, could lead to mildew and mold growth inside your HVAC system. This could potentially spread mold spores via your home’s air vents.

If, during a DIY or professional air duct inspection, you see something that even resembles mold, call up an expert who specializes in testing for and eradicating the pollutant. Left unchecked, mold can contribute to respiratory problems and other health problems.

There’s a Vermin Infestation

Dark, cozy, dry spaces give love-at-first-sight vibes for the likes of rodents and insects. And guess what your air ducts are? Yep – exactly that kind of environment. You’ll know you’ve got a pest problem on your hands if you notice droppings, hear the pattering of critters’ feet, smell a musty odor, see shed insect skins/eggs, or find chew marks.

Your Ducts Have a Massive Build Up of Allergens

According to the EPA, a light amount of dust and allergens in your air duct system isn’t going to cause you harm, especially since the majority of it tends to get stuck to the duct walls, never actually entering your living spaces. The same goes for the dust and dirt you might sometimes find on your return air vent grilles; simply wipe it away or vacuum them clean.

If, however, you or other people in your household are prone to allergies, have asthma, or are experiencing unexplained symptoms of illness you feel may be directly related to dirty air ducts, it may be a good idea to have them inspected and cleaned.

FAQ About When You Should Clean Your Air Ducts

Does air duct cleaning prevent health problems?

No. Research has never shown that dust and other allergens in air ducts represent any type of danger to human health. There’s also no evidence that professional air duct cleaning improves indoor air quality, as contaminants more often enter your home in the following ways:

  • shoes and clothing worn outdoors
  • smoking inside
  • cleaning with chemicals
  • regular movement that stirs up dust, etc.

Can air duct cleaning save energy costs?

The act of cleaning your air ducts will not lower your energy bills; however, if you discover your air ducts have any leaks, sealing those leaks can help make your air duct system more energy efficient, cutting those energy costs.

Additionally, studies have shown that cleaning your HVAC system’s individual components (rather than the air ducts) — think fans, coils, valves, and heat exchangers — may help increase energy efficiency and lower costs, as well.

Is air duct cleaning DIY-able?

Air duct cleaning is definitely a task you’ll want to leave up to the pros if you still decide you want to have this done. Before hiring an air duct cleaner, though, be sure to do your due diligence. The EPA recommends getting quotes from at least three air duct cleaning services and interviewing the cleaners who may potentially come to your home. 

Here’s how to know you’re hiring the right air duct company, according to the EPA:

  • They don’t promise improved health benefits.
  • They follow the National Air Duct Cleaners Association’s standards.
  • They don’t tout air duct cleaning as part of regular HVAC maintenance.
  • They have excellent references/reviews.
  • They don’t claim to be EPA-certified, as that doesn’t exist for air duct cleaning.

When to Hire a Professional

Again, air duct cleaning isn’t a service you’ll probably need, except under special circumstances (e.g., visible mold, extreme layers of dust and dirt, or pest infestations). If such a circumstance arises, definitely enlist the help of a professional air duct cleaner near you. They’ll give your air duct system a thorough inspection, protect pets and furnishings from harm/damage during cleaning, vacuum out ducts, and repair any damage they find.

Note: If visible mold is the problem, you’ll need to hire a mold removal specialist near you to tackle that part first. Air duct cleaners are not the same as mold removal experts.

Main Photo Credit: Kubrak78 / Canva Pro / License

Andréa Butler

Andréa Butler is a writer and editor. And while she hasn't been blessed with DIY skills herself, she is adept at writing and enjoys sharing home improvement tips and pool care guides for the true DIYers out there.