How to Tell If Mold Is Growing in Your HVAC System>

FHP AC Service | South Florida’s Trusted Indoor Air Quality Experts

Mold in your HVAC system is more than just an inconvenience—it can seriously impact your health and your home. But how do you know if it’s lurking inside your ducts, coils, or air handler?

At FHP AC Service, we help homeowners and business owners across South Florida identify and eliminate harmful mold in their HVAC systems. Here are the top warning signs to look out for—and what to do next.

⚠️ 1. Musty Odors Coming from Vents

That telltale musty smell is often the first sign of mold growth in your HVAC system. Mold thrives in damp, dark areas—like air ducts, drain pans, and evaporator coils. If the odor intensifies when your AC turns on, it’s time to schedule a professional inspection.

2. Increased Allergy or Asthma Symptoms

Experiencing sudden or worsening:

  • Sneezing

  • Coughing

  • Eye irritation

  • Headaches

  • Fatigue?

Your HVAC system could be circulating airborne mold spores. Mold exposure affects indoor air quality and can worsen existing respiratory issues, especially for children, the elderly, or those with compromised immune systems.

️ 3. Visible Mold on Registers or Around the Air Handler

Check your supply vents and return grilles. Do you see black, green, or brown discoloration? Mold may also be visible around the air handler, blower fan, or inside your HVAC cabinet. Even a small amount of visible mold can indicate a larger, hidden problem inside your system.

️ 4. Excessive Moisture, Leaks, or Condensation

Mold needs moisture to grow. Leaking ducts, a clogged drain line, or poor ventilation can create the perfect conditions for mold buildup. Signs to watch for:

  • Water pooling around your indoor unit

  • Condensation on ducts or vents

  • Mold stains on walls or ceilings near HVAC equipment

5. Poor Airflow or System Performance

A mold-contaminated coil or duct can restrict airflow, making your system work harder. If you’ve noticed:

  • Uneven cooling

  • Reduced air pressure

  • Higher energy bills
    … your system might be battling both mold and inefficiency.

What to Do If You Suspect Mold in Your HVAC

Don’t try to DIY this one—disturbing mold can spread spores into the air and worsen contamination. Instead:

✅ Schedule a professional HVAC mold inspection
✅ Consider air quality testing (we offer spore sampling & particle counts)
✅ Get expert remediation using HEPA vacuums, antimicrobial treatments, and UV light technology

️ How FHP AC Service Handles Mold Remediation

At FHP AC Service, we offer certified HVAC mold remediation across Broward, and Palm Beach Counties. Our process includes:

  • Full HVAC system inspection

  • Duct cleaning with HEPA-grade vacuums

  • Application of EPA-approved mold inhibitors

  • UV light installation for ongoing protection

  • Optional indoor air quality upgrades (dehumidifiers, filtration, etc.)

Serving South Florida with Certified HVAC Expertise