Most homeowners don't think about their air ducts until something goes wrong and by then, the dust, dander, and debris have been recycling through every breath their family takes for years. Here are 10 clear warning signs that mean it's time to schedule a professional cleaning.
1. Visible Dust Around the Vents
Dust the area around your supply registers. Run the HVAC for a day or two. Look again. If dust is collecting on or near the vents faster than anywhere else in the room your ducts are pushing it. That's the most common visual sign of a system that needs cleaning.
2. Musty or Stale Smell When the System Runs
Turn on the AC after a long off period. Does the air smell musty for the first few minutes? That's biofilm or mold growing inside the duct system or on the evaporator coil. Cleaning removes the source of the smell and a sanitization treatment kills what's left.
3. Allergies That Get Worse Indoors
If your allergy symptoms worsen when you're home especially when the HVAC is running your ducts may be circulating allergens. Dust mites, pet dander, pollen, and mold spores all collect in ductwork and get pushed out every time the fan turns on.
4. Pets That Shed (And Have Been Around for Years)
Pet hair and dander accumulate in duct systems faster than any other contaminant. If you've had shedding pets for several years and never had professional cleaning there's a substantial layer of pet hair coating your duct interiors. Remove it.
5. You Just Moved Into a New (or New-to-You) Home
Two scenarios both call for cleaning:
New construction: Drywall dust, sawdust, and construction debris settle into duct systems during the build and never come out on their own.
Resale homes: You don't know who lived there before, what they cooked, whether they smoked, or when they last cleaned. Start fresh.
6. Recent Home Renovations
Any major remodel kitchen, bath, basement, addition sends fine dust through the entire HVAC system. Even if you sealed off the work area, microscopic drywall dust and sawdust always finds its way into the ducts. Schedule a cleaning when the project finishes.
7. Visible Mold at the Registers
If you see black or dark green spots on the register vents themselves, or if there's visible mold on the air handler there's a mold problem in the system. Don't cover it up; clean it. Sanitization is also recommended in this case to kill any remaining microbial growth.
8. Energy Bills Have Crept Up
If your energy bills are higher than the same time last year and you can't explain why, dirty ducts may be the culprit. A clogged blower wheel and dirty coil make the HVAC work harder to move the same air. The result: higher bills, more wear, less performance.
9. The HVAC Is Running Longer to Reach Setpoint
Notice the AC is running 30, 40, 50 minutes per cycle when it used to run 20? That's a system struggling to push air through dirty ducts and a dirty coil. Cleaning often restores the original performance.
10. It's Been More Than 5 Years
If you can't remember the last time you had professional cleaning, or it's been more than 5 years it's overdue. Even without any of the other signs, 5+ years is enough time for substantial buildup, especially in St. Louis' humid climate.
What to Do Now
If you noticed any of these signs in your home, the next step is simple: call a family-owned, BBB-accredited cleaner for a free quote. Get a free estimate or call (314) 718-3632 we'll ask a few questions and tell you honestly whether your home is overdue.