Duct cleaning has become popular in recent years with many commercial cleaners advertising this service. If you’ve never paid to have it done, are you missing out? Is your home dirtier as a result? I came across a filthy air vent cover during my inspection today so it inspired me to dig into the topic. Here’s some information to help you decide whether or not your home might benefit from having the HVAC ducts professionally cleaned. 

Have You Changed Your Air Filter Recently?

Your furnace’s air filter should be changed regularly to keep your system running smoothly and to maintain optimal air quality. There are several factors that contribute to the longevity of your air filter, here are a few general guidelines: 

  • Home size. Larger homes circulate larger amounts of air which means the filter may need to be changed more frequently than those in smaller homes. I recommend the “average” suburban home without pets change their filter every three months. 
  • Pets. Since common household pets can shed and track in dirt from outside, you’ll need to change the filter regularly to keep it clear of pet hair and dander, roughly every two months.
  • Allergies or medical conditions. Homeowners with severe allergies, asthma or other respiratory conditions should consider changing the air filter once a month to prevent flare ups. 



Your air filter is meant to capture airborne particles like dust, pollen, pet dander, and bacteria before they enter the ductwork. If you fall behind on replacing your filter, your home’s duct system will be the landing spot and a proper cleaning may prove worthwhile. 

Can You See Visible Dust on the Registers and Vent Covers?

We all have the best intentions of dusting our homes regularly, but this chore sometimes gets overlooked. Dirty air ducts often reveal themselves through dust buildup on your vent covers and registers. You might also see unusual levels of dust distributed around your home, prompting you to wonder if you cleaned as well as you thought you did. If this sounds familiar,  it may be worth having your ducts cleaned to ensure you are not recycling dust through your duct system.



Do You Detect Mold In or Around Your HVAC System?

Dust can negatively affect your health, but mold can prove far more serious. Not only can microbial growth exacerbate allergies and respiratory problems, but it can also spread quickly through your home. Whether you spot mold around the vent covers, or you see it growing around your indoor air conditioning unit, it’s important to take action quickly to preserve your home’s indoor air quality.


mold in vent


In addition to a complete duct cleaning, it may be valuable to invest in a moisture intrusion investigation to identify how or why excess moisture is getting into your home.  Mold grows in wet areas, something you can limit with a whole-home dehumidifier or even optimized settings on your programmable thermostat. If your air conditioning unit seems to attract mold and other bacteria, an ultraviolet (UV) germicidal light can offer a straightforward solution.

Can You Hear Noises in the Ductwork?

After you’ve lived with your HVAC system for a few months or years, you become accustomed to its sound. What you might not realize, however, is that the ductwork shouldn’t generate additional noise. If you hear anything more than the blower motor or a general whooshing sound, this is a sign that your ductwork might have a blockage or accumulated dust and debris. On occasion I see evidence that vermin have made their way into the air duct system. If you notice droppings or a strange smell when you circulate air, I recommend you have the ducts properly cleaned. 

If the noise persists, you may need an HVAC technician’s expertise to fix a broken system component. 

Is Airflow Inconsistent from Room to Room?

If you’ve ever noticed that a bedroom or bathroom doesn’t receive the same level of airflow that other rooms do, you might have dust or debris in your duct system. After all, vents that are fully open should deliver relatively consistent airflow through every room in your home.

If you’ve determined some of these factors are a concern for you, it may be time to seriously consider air duct cleaning. 

How Much Does Air Duct Cleaning Cost?

According to Angie’s List, the average air duct cleaning for most homes costs between $300 and $500, with the price affected by factors like the size of the home, the number of ducts, and the configuration. The average per-vent price is $35. Beware of any companies offering unusually low prices. There are companies who claim to offer duct cleaning services but don’t actually clean your air ducts thoroughly. They may only clean a small portion of the ductwork (i.e. only the part of the ducts that are visible when peering into the registers). 

What does Air Duct Cleaning Entail?

Professional duct cleaning services use specialized blowers, vacuums, and brushes to clean out the supply, intake, and return ducts throughout your home. Duct cleaning should also involve a thorough cleaning of the air handler, registers, grilles, fans, motors, housings, and coils of the HVAC system.


duct cleaning brush


I haven’t come across any research proving routine duct cleaning improves the air quality or reduces dust in your home. There is, however, evidence that dirty heating and cooling coils, motors, and air handling units can make your HVAC unit less efficient. So, if you’re on the fence about air duct cleaning, I recommend doing it simply to support the efficiency and longevity of your HVAC system. Less dust circulating in your home is the obvious bonus benefit!