Mold in Your AC Unit? Coil & Air Handler Mold Removal in Austin

Your AC cools the air by pulling heat and moisture out of it. The moisture condenses on the evaporator coil, drips into a drain pan and leaves the house through a condensate drain line. When that works, the water is gone in minutes. When it doesn’t, the air handler becomes a dark, damp box full of dust, which is everything mold needs.

Central Texas makes it worse: systems run hard from late spring through fall, often from attic air handlers sitting in 120-degree heat. The causes we find most often:

• A condensate drain line clogged with algae or sludge, leaving standing water in the pan
• A rusted, cracked or poorly sloped drain pan that never fully drains
• Dirty coils and filters that hold moisture and feed growth
• Oversized systems that short-cycle, shutting off before they pull the moisture out of the air
• Air leaks in the cabinet or return that pull humid attic or garage air into the unit
• Systems left off, or set very high, in a vacant home during a humid stretch

The air handler feeds every room, so it’s usually the center of the work. First, an independent, licensed mold assessor evaluates the home and writes the protocol. If the mold is only in the HVAC system, Gold Eagle handles it as a licensed mold remediation company. If it’s also in walls, the attic or belongings, a general mold remediation company handles that part and we do the HVAC side. A typical coil and air handler job includes:

1. Protecting the rest of the home from dust and debris, inside the other company’s containment when one is on the job
2. Opening the cabinet and HEPA vacuuming loose debris
3. Cleaning the evaporator coil and fins with coil-safe methods, or replacing the coil when it’s badly corroded or can’t be cleaned effectively
4. Cleaning or replacing the blower wheel and treating the cabinet surfaces
5. Removing and replacing contaminated internal insulation, which is porous and usually can’t be cleaned
6. Replacing or re-leveling the drain pan and clearing, re-sloping or re-routing the condensate drain
7. Checking the float switch, filter rack and cabinet seals so humid air and water stay where they belong

Opening and replacing AC parts takes an air conditioning license, and cleaning and treating mold in the system is remediation work. We hold both licenses, so we can legally do both halves of the job inside the unit. If the ducts are affected too, see duct mold removal and replacement.

Sometimes cleaning an old unit isn’t the best use of your money. Replacement is worth discussing when the coil is leaking refrigerant or heavily corroded, the cabinet insulation and blower are badly contaminated, the system is near the end of its life, or it’s the wrong size for the house and keeps causing humidity problems. A right-sized system with proper airflow runs long enough to pull the moisture out, which makes a repeat problem less likely.

We’ll show you what we found and lay out both options. Learn more about AC repair and installation.

• Change filters on schedule, usually every 1 to 3 months
• Keep the condensate drain clear, and have it flushed during annual maintenance
• Keep indoor humidity between about 40% and 50%; if your AC can’t, consider a whole-home dehumidifier
• Don’t shut the AC off in summer when you travel; set it a few degrees higher instead
• Seal leaks in the return and cabinet so the system isn’t pulling in attic air

Coil mold rarely stays at the coil:

• HVAC restoration: how an HVAC mold job runs, from assessment to clearance
• Duct mold removal: when mold has spread into the ducts and plenums
• Signs of mold in your HVAC system: what to watch for before it spreads

If you’d like the background first, these guides cover why coils grow mold, why an AC ices over or leaks water, and how to keep mold from starting:

• Could Your HVAC System Be Secretly Growing Mold?
• Why Is My AC Freezing Up or Leaking Water?
• Best Practices for Mold Prevention in Your HVAC System
• Austin Mold Facts
• Whack-a-Mold (a quick game)

See every guide in the Resource Center