Austin's AC: Mold Hiding Summer Allergies?

By Franklin Everett Shaw

November 6, 2025

The relentless Texas sun beats down, and you crank up the AC. Relief washes over you, but then… a tickle in your throat, a scratchy nose, and watery eyes. Is it just summer allergies, or is something more sinister lurking in your air conditioning system? In Austin, where humidity reigns supreme, mold growth in AC units is a common, yet often overlooked, culprit behind allergy flare-ups. It’s time to take control of your indoor air quality and breathe easy again.

Mold thrives in the dark, damp environments of AC systems. The evaporator coil, in particular, is a prime breeding ground. Condensation forms as the unit cools, and dust, pollen, and other organic matter provide the perfect food source. This creates a toxic cocktail that circulates through your home every time you turn on the AC.

So, how do you know if your Austin AC unit is harboring mold? Start with your senses. A musty, earthy odor emanating from your vents is a major red flag. Also, pay attention to your health. Increased allergy symptoms, such as sneezing, coughing, itchy eyes, and a runny nose, especially when the AC is running, can indicate mold exposure.

Here’s a step-by-step guide to checking your AC unit for mold:

1. Safety First: Turn off the AC unit at the breaker box. This prevents electrical shock and ensures the fan doesn’t kick on while you’re inspecting it.

2. Locate the Evaporator Coil: This is usually inside the indoor unit, often in the attic or a closet. You’ll need a screwdriver to remove the access panel. Be careful not to damage any wires or components.

3. Visual Inspection: Use a flashlight to thoroughly examine the evaporator coil and surrounding areas. Look for visible mold growth, which can appear as black, green, brown, or white patches. Pay close attention to the fins of the coil, as mold often hides in these crevices.

4. Smell Test: Even if you don’t see visible mold, a strong musty odor is a strong indicator of its presence.

5. Check the Drain Pan: The drain pan collects condensation from the evaporator coil. If it’s clogged or overflowing, it creates a perfect environment for mold growth. Look for standing water and signs of mold around the drain opening.

6. Inspect the Air Ducts: While you’re at it, take a peek inside your air ducts. Use a mirror and flashlight to get a better view. Dust and debris are normal, but visible mold growth warrants further investigation.

If you suspect mold growth, it’s crucial to get a professional mold test. Several companies in Austin specialize in indoor air quality testing. They can take samples and identify the specific types of mold present, which is essential for effective remediation.

Here are a few reputable mold testing services in the Austin area:

• Mold Inspection Sciences Texas: They offer comprehensive mold testing and inspection services, including air and surface sampling.

• EnviroHealth Consulting: Specializes in environmental testing and consulting, including mold assessments for residential and commercial properties.

• RTK Environmental Group: Provides mold testing and inspection services with a focus on accurate and reliable results.

Once you’ve confirmed the presence of mold, professional remediation is often necessary. Mold remediation is not a DIY project, especially for large infestations. Improper cleaning can actually spread mold spores and worsen the problem.

Here’s what a professional mold remediation process typically involves:

1. Containment: The affected area is sealed off to prevent mold spores from spreading to other parts of the house.

2. Source Removal: The source of the moisture problem is identified and corrected to prevent future mold growth.

3. Cleaning and Disinfection: Mold-infested materials are removed and disposed of properly. Surfaces are cleaned and disinfected with antimicrobial solutions.

4. Air Filtration: HEPA air filters are used to remove mold spores from the air.

5. Post-Remediation Testing: After the remediation is complete, a final mold test is conducted to ensure that the mold has been successfully removed.

Preventing mold growth in your AC system is key to avoiding future allergy flare-ups. Here are some practical tips for Austin residents:

• Regular AC Maintenance: Schedule annual AC maintenance with a qualified technician. They can clean the evaporator coil, drain pan, and other components to prevent mold growth.

• Change Air Filters Regularly: Replace your air filters every 1-3 months, depending on the type of filter and the level of dust and pollen in your home. This helps to keep the AC system clean and prevent mold spores from circulating.

• Keep the Drain Line Clear: Pour a cup of bleach down the AC drain line every few months to prevent clogs and mold growth.

• Control Humidity: Use a dehumidifier to keep the humidity level in your home below 50%. This helps to prevent mold growth in the AC system and throughout the house.

• Improve Ventilation: Ensure that your home is properly ventilated to reduce moisture buildup. Open windows and doors when possible, and use exhaust fans in bathrooms and kitchens.

• UV Lights: Consider installing a UV light in your AC system. UV lights kill mold and bacteria, helping to keep the system clean and prevent mold growth.

One common mistake Austin homeowners make is neglecting regular AC maintenance. They wait until the AC breaks down before calling a technician, by which time mold may have already taken hold. Another pitfall is attempting DIY mold removal without proper training or equipment. This can actually worsen the problem and expose you to harmful mold spores.

Living in Austin means embracing the heat, but it doesn’t mean suffering from mold-related allergies. By taking proactive steps to identify and remediate mold growth in your AC system, you can breathe easier and enjoy a healthier indoor environment. Don’t let mold ruin your summer – take control of your air quality today.