Top 5 Signs You Have Mold Growing in Your Air Ducts (And What to Do About It)
- Writer
- Oct 5
- 4 min read
Houston homeowners know how tough it can be to stay comfortable during the long, humid months. Unfortunately, that Houston humidity doesn’t just make you feel sticky - it also creates the perfect environment for mold to grow inside your home’s air ducts.
If you’ve ever noticed a musty odor when your AC kicks on, or strange allergy symptoms that just won’t quit, mold might be the hidden culprit. The good news? With the right mold remediation and air duct cleaning professionals, you can restore your home’s comfort, air quality, and peace of mind.
Here’s how to spot the warning signs before mold takes over your vents - and what to do if you discover it.
Musty or Damp Odors When the AC Runs
The first and most common sign of black mold in vents is that unmistakable musty smell that fills the air whenever your HVAC system turns on.
Mold thrives in dark, damp environments - and air ducts provide both. When spores build up, they release a stale odor that spreads throughout your home. If your air smells “wet,” “old,” or “mildewy,” it’s time to take action.
What to do:Turn off your HVAC system and contact a mold remediation specialist immediately. Running the air could spread spores further. A professional team like Supreme Duct Cleaners can perform an inspection and deep clean your ducts to eliminate the source of the odor safely.
Unexplained Allergy or Respiratory Symptoms
Do you find yourself sneezing, coughing, or dealing with watery eyes only when you’re at home? You might not be imagining it.
Mold spores are microscopic allergens that can trigger respiratory problems, especially in children, the elderly, or anyone with asthma. As your HVAC system circulates air, it can push those spores into every room of your home.
Over time, mold exposure can cause:
Constant sneezing or congestion
Coughing and throat irritation
Headaches or fatigue
Skin rashes or itchy eyes
What to do:If these symptoms seem to worsen when you’re indoors, schedule an air duct cleaning service. Supreme Duct Cleaners uses advanced HEPA-filtered equipment to remove contaminants and allergens, improving your home’s air quality so you can breathe easier.
Visible Mold or Black Spots Around Air Vents
Seeing small black or green spots around your vent covers? That’s one of the clearest signs of black mold in vents.
These spots are usually mold colonies feeding on dust and moisture trapped in your duct system. Even if it looks like surface dirt, it could be mold - and disturbing it can release thousands of spores into your living space.
What to do:Do not wipe or scrape the area yourself. Mold spores can spread easily, especially when disturbed. Instead, contact professionals trained in mold remediation who can properly seal, clean, and disinfect the ductwork. Supreme Duct Cleaners’ team is equipped with specialized tools and EPA-approved cleaning agents to ensure a complete, safe removal.
Weak Airflow or Higher Energy Bills
Mold growth in your duct system doesn’t just affect your health - it also impacts your HVAC performance.
When mold, dust, and debris build up inside the ducts, it restricts airflow. Your system has to work harder to push air through, leading to:
Higher electricity bills
Uneven heating or cooling
Shorter HVAC lifespan
💨 What to do: Regular air duct cleaning keeps your system running efficiently. Supreme Duct Cleaners recommends having your ducts inspected at least once a year, especially in Houston’s humid climate, where moisture buildup happens fast.
Condensation or Moisture in or Around Vents
Remember that Houston humidity we mentioned earlier? That same sticky air can lead to condensation inside your duct system. Over time, that moisture becomes the breeding ground for mold and bacteria.
If you notice water stains around your vents, damp insulation, or puddles near your air handler, there’s a good chance mold is already growing.
💧 What to do:This is a job for professionals. Supreme Duct Cleaners not only removes the mold but also identifies the source of the problem, whether it’s poor insulation, air leaks, or excessive humidity - to help prevent it from coming back.
How Mold Remediation Works
At Supreme Duct Cleaners, our mold remediation process is designed to remove existing mold and stop it from spreading. Here’s what to expect:
Inspection: We locate all mold-affected areas and measure humidity levels.
Containment: Our team seals off the affected zones to prevent spore spread.
Cleaning & Disinfection: Using professional-grade vacuums and EPA-approved products, we remove all visible and airborne mold.
Air Duct Treatment: We perform a thorough air duct cleaning, ensuring the entire system is clear.
Humidity Control: We identify long-term solutions, such as insulation upgrades or moisture barriers, to keep your ducts dry and mold-free.
Protect Your Home from Mold Year-Round
Houston’s humid weather makes it almost impossible to avoid moisture - but with regular maintenance and professional cleaning, you can keep your home safe, healthy, and efficient.
✅ Schedule air duct cleaning at least once a year
✅ Use a dehumidifier in high-humidity areas
✅ Change your air filters regularly
✅ Keep your HVAC system serviced and inspected
🏡 Don’t Let Mold Take Over Your Home
If you suspect black mold in vents or want to prevent it before it starts, call the experts at Supreme Duct Cleaners. We provide professional mold remediation, air duct cleaning, and indoor air quality services to help Houston families breathe cleaner, healthier air - no matter how humid it gets outside.
📞 Call today: (832) 346-6460
📍 Serving: Houston, Humble, Katy, The Woodlands, Galveston & surrounding areas
