11 Common Signs of Dirty Air Ducts and What to Do Next
Dirty ducts can cause a slew of problems, including high power bills
Highlights
Clogged vent covers and air filters indicate it’s time for a cleaning.
Unusual noises in and around your HVAC system could signify a problem.
If you notice a spike in your power bill, dirty air ducts may be to blame.
To ensure your ducts are thoroughly cleaned, hire a professional.
No matter how clean you keep your house, your air ducts accumulate dirt, dust, and debris over time. Left unchecked, this gunk can build up and form blockages in your ducts, leaving you with a dirty and inefficient duct system. Keeping your ducts clean will help. Here’s how to know it’s time to get your air ducts cleaned.
1. Dirty Vent Covers
Every month, take a stroll around your house and look closely at each of your vent covers. If you notice significant dirt or debris buildup, there are likely blockages or contaminants in your ductwork. Dirty vents are a clear sign of dirty air ducts.
2. Clogged Air Filters
In general, you should change your air filters every 90 days, or every 60 days if you’re allergic to dust or pet dander that accumulates in your ducts over time. Air filters trap these contaminants and prevent them from circulating throughout your home. If you can’t remember the last time you replaced your air filter, it’s probably overdue for one before your ducts start accumulating build-up.
3. Visible Mold Growth
Mold and mildew in air ducts exacerbate allergies and respiratory conditions. It grows quickly, and if it’s left unchecked, it can cause serious structural damage to your home.
While checking for dirt buildup on your vent covers each month, look for signs of mold growth in your air ducts. If you see discoloration near your vents or other HVAC components, hire a specially trained mold removal specialist near you to handle it. If you ignore it now, you may end up paying thousands of dollars for mold remediation in the future.
4. Noisy Air Ducts
Besides the faint hum of the motor running, your HVAC system shouldn’t make a lot of noise. If you hear loud noises in your HVAC system, like pops, bangs, or rattles, you could have an issue, like a blockage. Schedule a duct cleaning if you hear any strange sounds coming from your ductwork.
5. Weak Airflow
If one of the rooms in your home is always much colder than the rest, you may have a problem with buildup in your ducts. First, check to see that all of your vents are open. If they are and you’re still noticing an unexplained temperature difference between rooms in your house, clean your ducts to remove buildup and blockages that could be cutting off airflow in your home.
6. Signs of Rodents or Insects
Rodents, insects, and other vermin love to set up shop in cozy, warm air vents. But their presence isn’t healthy for you or your family—the smell of their droppings, fur, or shells can be extremely unpleasant and make your family members sick.
You’ll know you have a vermin problem if you see, smell, or hear them shuffling in your ductwork. To get rid of them, hire an animal removal service near you. Then, have your ducts professionally cleaned to remove any harmful substances they left behind.
7. Unusually High Power Bill
Your heating and cooling costs should be predictable every year. If you’ve lived in your house for more than one year, you likely know the general utility costs associated with each season. But that’s not an excuse to ignore your bill. If you notice any unusual spikes throughout the year, there could be a problem.
An unusually high power bill could be a sign that your ductwork is dirty. Dirt, dust, and debris buildup can prevent your HVAC system from running efficiently. If you notice a spike in your bill, consider cleaning your ductwork.
8. Smelly Ducts
An unpleasant odor coming from your ducts is a sign of mold, mildew, or vermin. If you notice a smell when you’re near your vents or other HVAC components, it’s time to clean them. Hire an HVAC inspector to assess the situation and determine if you do, in fact, have mold or vermin. If that’s the case, you may need a specialized professional to tackle the problem.
9. Increase in Dust Around the House
An increase in dust build-up in your home, particularly around your air vents, could indicate that it’s time to clean your ducts. When dust and other particles build up in your ductwork, as the air circulates through, it pulls the particles with them.
Clean your air vents at least once a month with a microfiber cloth or vacuum attachment. If you don't notice any dust building up around your furniture, then it’s likely just dirty vents. However, if your air vents look dusty even after regular vent cleanings, then cleaning your ducts is a wise next step.
10. Recent Home Repair or Renovation
When you make a home repair or renovation, all the sawing, nailing, and moving things can kick up dust and other particles. As the particles become airborne, they’ll travel through your ductwork. Depending on the type of particles they are and how clean your air filter is, some might seep through into the ductwork. So you should always clean your ductwork after doing a major home improvement project, especially a messy one.
11. Increase in Allergy-like Symptoms
If you’re sneezing, have a scratchy throat, or other allergy symptoms, the culprit is likely the air you’re breathing. Dirty ductwork allows dust, pollen, and other respiratory irritants to filter through your air vents and into your home.
Along with cleaning your air ducts regularly, if you’re a regular allergy sufferer, it’s ideal to pay close attention to the air filters you install. Some air filters offer higher levels of protection, removing mold, bacteria, dander, and other particles from the air. They will be more expensive, but they’re worth it if they give your allergies a time-out.
But if you’re still experiencing symptoms after cleaning your ducts, you should consult a doctor for further analysis.
What to Do If Your Air Ducts Need Cleaning
You can clean your air ducts yourself with a strong vacuum and a few scrub brushes if you only need a basic cleaning. But if you notice any of the warning signs discussed above, you should hire a pro. That’s especially true if you see or smell mold, mildew, or vermin. A professional will have the right training and tools to clean your ducts thoroughly. Hire a professional air duct cleaner near you to have your air ducts cleaned well.
Air duct cleaning costs average about $400, but this varies depending on the size of your home and how accessible the ducts are.
Lauren Murphy contributed to this article.
Frequently Asked Questions
To see dirty ducts, watch your air vents as your HVAC kicks on. If it puffs out a small cloud of dust, you probably have dirty air ducts. You’ll also notice you have dirty ducts if you have to clean your air vents more than once per month, you’re suffering from allergy symptoms more, or you notice more dust accumulation on furniture near air vents.
When air ducts become dirty, it impedes the ability to push air through. And the air going through will be dirtier. As such, your HVAC will work harder to balance the temperature and humidity in your home. You might hear it kick on more often, and you’ll definitely notice a spike in your energy bills. That’s why hiring a local air duct cleaner is worth it. You’ll breathe cleaner air, keep your home more comfortable, and reduce the work your HVAC must do.