Your Complete Guide to Cleaning Air Ducts in Spring

Fact checked by Olga Sadouskaya, MD
Clinical Pharmacologist, Chief Medical Officer

When spring’s around the corner, many people start cleaning their homes: wiping the dust and rain spots from their windows, clearing out clothes they no longer wear from their wardrobes, switching out home decor… But what about their air ducts and vents?

In theory, cleaning air ducts makes a lot of sense — dust, dander, dirt, and hair are all too comfortable hanging out in your air vents and ducts, polluting the air you breathe. But is it safe to do? And are there any telltale signs your air ducts need cleaning? Continue reading to find out!

Do you need to clean air ducts?

Dirt, dust, pet dander, and other airborne particles can accumulate in your air ducts. This can make your heating and cooling systems work harder and use up more energy, raising your bills.

However, little research has been done into the health effects of duct cleaning. Government studies from the United States and Canada, as well as health professionals who have investigated duct cleaning, show little evidence that cleaning air ducts alone can improve indoor air quality.

A small amount of household dust accumulating in your air ducts doesn’t pose any significant health risks.

But in some cases, duct cleaning is necessary, for example, if you have:

  • Insects, rodents, and other animal infestation inside your HVAC system
  • Home renovations that damage the existing ductwork
  • Ductwork and floor supply registers that haven’t been properly sealed
  • Deteriorated sealants around air vents

How often should you clean air vents, heating ducts, and HVAC systems?

The Environmental Protection Agency doesn’t recommend cleaning air ducts as part of routine home maintenance, as there’s no conclusive evidence that it can actually prevent any health problems.

That being said, duct cleaning isn't a bad idea — it's just not always necessary. Experts recommend cleaning your air ducts at least once every three years, or whenever there are clear signs that it’s time to clean your HVAC ducts.

Signs your air ducts need cleaning

The EPA recommends cleaning air ducts if there’s visible evidence of:

  • Significant mold growth. Condensation in your heating and cooling system can lead to mold growth in your ducts, especially if you live in a humid climate. You may not see mold around your vent covers, but it usually manifests itself as a musty odor. An air duct cleaning can help get rid of the mold and unpleasant smells in your home. But to prevent mold growth in the future, consider installing a whole-house dehumidifier or adjusting your thermostat settings to keep the humidity level under control.
  • Insect or rodent infestation. Mice, squirrels, and insects can get into your air ducts from time to time. Naturally, these pests leave a slew of bacteria behind. When rodents enter your ductwork, they build nests and leave droppings, sending tiny fecal spores scurrying along your vents, contaminating the air you breathe.
  • Significant dust deposits. Dirt, dust, pet dander, and other contaminants can linger in the air ducts of even the cleanest homes. You may even notice dust coming out of the vents whenever the HVAC system is turned on! If this is the case, your air ducts may need cleaning.

If anyone in your household has a certain health concern, such as allergies or asthma, consult your doctor first. They can help identify if the dirty air ducts are the problem and if cleaning them will help.

3 reasons you should regularly clean air ducts

1. Keeps allergies at bay

Respiratory conditions like asthma and allergies are serious problems for many people. The build-up of dust, bacteria, or mold spores in your air ducts may aggravate any preexisting conditions.

Cleaning your air ducts and — most importantly — regularly changing air filters can help keep allergies and asthma under control.

Your filters can get dirty pretty quickly, depending on the season and air quality. But most of them should be replaced every 2–3 months.

If you want to further improve your indoor air quality, consider getting an air purifier. HVAC system filters and air purifiers both trap airborne particles such as dust, pollen, tobacco smoke, and pet dander, helping to prevent allergy and asthma flare-ups.

2. Removes unpleasant odors

Different smells can circulate in your home during the day. It could be something you cooked, cleaning products, paint fumes, or even tobacco. These odors can linger in your home, clinging to your carpets, curtains, or furniture. You may stop noticing these smells after a while, but your guests won’t be immune to them.

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Duct cleaning alone won’t solve this problem — even if you use an anti-microbial spray as part of the cleaning process. But if the smell appears suddenly and is coming directly from the vents, they may be contaminated with:

  • Rodents and other small animals
  • Their droppings and fur deposit
  • Mold and mildew from excess moisture build-up

In this case, cleaning your air ducts and removing the contaminant can eliminate the unpleasant odors. Once the source of the smell is removed, consider adding or upgrading your air purification system to help keep the air in your home clean.

3. Improves air circulation

If you allow dust and debris to accumulate in your air ducts, your HVAC system has to work harder to push air through the dirt and into your home. This happens because the air doesn't flow smoothly, which prevents the system from reaching the desired temperature.

Additionally, because your HVAC system is working harder than it should, your energy and maintenance bills may go up. When you clean your air ducts, your HVAC system can serve longer and can save you money that would otherwise be spent on costly repairs.

How to clean vents, HVAC ducts, and ducted heating in your house

Since heating and air duct cleaning should ideally be done every three years, it’s best to hire a professional for the job to save you the bother. But if you prefer a more hands-on approach, here’s how you should go about cleaning the air ducts in your home:

  • Turn off your HVAC system at the thermostat or by shutting off the circuit breaker.
  • Remove the grilles. Floor supply registers typically aren’t attached, so they lift off easily. But for ceiling and wall ducts you may need to use the drill to turn out the screws holding the grilles in place.
  • Cover the vent with paper towels. It prevents dust from blowing out of them and landing on your walls and floor.
A person cleaning air ducts
  • Clean the grilles with warm water, mild detergent, and a soft brush. Set them against a wall to dry.
  • Break the dust and other contaminants loose. Push your cleaning brush — something that looks like a toilet brush will work well, but any stiff-bristle paint brush should also do the trick — into the duct to agitate the dirt build-up.
  • Vacuum it up. Be patient, any debris that isn't vacuumed out will be blown back into the room when you restart the HVAC system. To avoid losing the nozzle of your vacuum in your ductwork, secure it to the hose with duct tape.
  • Change your filters. Now that you've successfully removed some of the dust from your ducts, replace your air filter to keep your indoor air clean.
  • Replace the cleaned grilles and vent covers when they’re dry.
  • Turn your HVAC system back on. Let it run for about 20 minutes. Turn it off and check the filter — it’ll catch any contaminants that the vacuum hasn’t removed. If there’s a lot of dust and dirt on this filter, replace it with a new one.

Note: You shouldn't clean your vents yourself if you have asthma, allergies, or any other respiratory conditions. A lot of dust can get whisked into the air during the process, so it may trigger your symptoms.

When to call a professional

Cleaning some advanced HVAC systems may require specialized knowledge and tools. If you don’t feel like getting into the complicated process of cleaning your air ducts yourself, it may be best to hire a professional, especially if the ducts are hard to reach.

Professional duct cleaners use commercial-grade vacuum systems and powered brushes best suited for thorough air duct cleaning.

A professional can remove large items such as dead vermin and construction materials that you can’t clean yourself. They are also trained to detect other issues in HVAC systems that the average homeowner may not be aware of.

In conclusion

​​With springtime comes the perfect opportunity to freshen up your home, and that includes your air ducts. The warmer weather brings an influx of pollen and other allergens, which can quickly build up in your air ducts and cause problems for allergy sufferers. By following the tips in this guide, you can ensure that your air ducts are clean and free of allergens, dust, and other debris. So take some time this spring to give your air ducts a good cleaning to breathe easier during the allergy season.

January 12, 2023