Houston Heat: Is AC Fueling Deadly Lung Fungus?

By Franklin Everett Shaw

January 3, 2026

The air hangs heavy and thick, a constant reminder of Houston’s notorious humidity. It’s not just uncomfortable; it’s a breeding ground. A breeding ground for mold, mildew, and, most concerningly, Aspergillus fungus, which can lead to a serious lung infection called pulmonary aspergillosis. For Houstonians, especially those with pre-existing lung conditions, understanding and mitigating this risk is crucial.

Pulmonary aspergillosis isn’t a casual sniffle; it’s a potentially life-threatening infection. It thrives in damp environments, making our air conditioning systems prime real estate for fungal growth. This isn’t scaremongering; it’s a call to action, a guide to protecting your lungs in the face of Houston’s unique environmental challenges.

The key weapon in this fight? Proactive AC maintenance.

Here’s a step-by-step guide to minimizing Aspergillus growth in your AC system:

1. Filter Frenzy: This is your first line of defense. Replace your AC filter at least every 30-60 days, and even more frequently during peak humidity (June-September). Don’t skimp on quality; opt for a MERV 11 or higher filter to trap smaller fungal spores. A common mistake is waiting until the filter looks dirty. By then, it’s already overloaded and less effective. Set a recurring reminder on your phone.

2. Coil Combat: The evaporator coil inside your AC unit is a dark, damp haven for mold and fungus. Cleaning it is essential.

   • Power Down: Always disconnect the power to your AC unit before cleaning. Safety first!
   • Access Granted: Remove the access panel to expose the evaporator coil. This might require a screwdriver. Consult your AC unit’s manual if you’re unsure.
   • Gentle Cleaning: Use a fin comb to straighten any bent fins. Then, apply a no-rinse evaporator coil cleaner (available at most hardware stores like Home Depot on I-10 or Lowe’s in Katy). Follow the product instructions carefully.
   • Professional Touch: Consider hiring a professional AC technician from a local Houston company like Reliant or Green Star Home Services for a deep cleaning at least once a year. They have specialized equipment and knowledge to thoroughly disinfect the coils.

3. Drainage Duty: A clogged condensate drain line can lead to standing water, creating a perfect breeding ground for Aspergillus. Locate the drain line (usually a PVC pipe near the outdoor unit) and check for clogs. You can use a wet/dry vacuum to suck out any debris. Pouring a cup of diluted bleach down the drain line every few months can also help prevent clogs and fungal growth.

4. Ductwork Diligence: Your ductwork is the highway through which air (and potentially fungal spores) travels throughout your home. Inspect your ductwork for leaks or damage. Seal any leaks with duct tape or mastic sealant. Consider having your ductwork professionally cleaned every 3-5 years, especially if you have a history of mold or allergies. Companies like Aeroseal of Houston specialize in duct sealing.

5. Humidity Harmony: Maintaining a comfortable humidity level inside your home is crucial. Aim for a humidity level between 30-50%. Use a dehumidifier, especially in areas prone to dampness, like bathrooms and basements (if you have one in Houston!). Ensure proper ventilation in your home by opening windows regularly (when the humidity isn’t too oppressive) and using exhaust fans in bathrooms and kitchens.

Recognizing the early symptoms of pulmonary aspergillosis is vital, especially for those with pre-existing conditions common in Houston, such as:

• COPD (Chronic Obstructive Pulmonary Disease): Houston’s air quality, often impacted by petrochemical industry emissions, can exacerbate COPD. Individuals with COPD are more susceptible to aspergillosis. Watch for increased shortness of breath, persistent cough, and wheezing.

• Asthma: The humid climate and pollen counts in Houston can trigger asthma attacks. If you have asthma, be extra vigilant about monitoring your symptoms. A new or worsening cough, chest pain, or fever could indicate aspergillosis.

• Cystic Fibrosis: This genetic condition affects the lungs and makes individuals more vulnerable to lung infections. People with cystic fibrosis should be particularly cautious about Aspergillus exposure.

• Weakened Immune Systems: Individuals undergoing chemotherapy, organ transplant recipients, or those with HIV/AIDS are at higher risk.

Specific Symptoms to Watch For:

• Persistent Cough: A cough that doesn’t go away, especially if it produces blood or mucus.
• Shortness of Breath: Difficulty breathing or feeling like you can’t get enough air.
• Chest Pain: Pain or discomfort in your chest.
• Fever: A temperature of 100.4°F (38°C) or higher.
• Wheezing: A whistling sound when you breathe.
• Fatigue: Feeling unusually tired or weak.

When to Seek Immediate Medical Attention:

If you experience any of these symptoms, especially if you have a pre-existing lung condition or a weakened immune system, seek immediate medical attention from a Houston-area medical professional. Don’t delay; early diagnosis and treatment are crucial.

Here are some reputable hospitals and clinics in Houston:

• Houston Methodist Hospital: Known for its pulmonary specialists.
• Baylor St. Luke’s Medical Center: Offers comprehensive respiratory care.
• MD Anderson Cancer Center: If you have a weakened immune system due to cancer treatment, MD Anderson is a leading cancer center with expertise in infectious diseases.
• UTHealth Harris County Psychiatric Center: If you are experiencing anxiety related to your health, UTHealth Harris County Psychiatric Center can provide mental health support.

Common Mistakes and Pitfalls:

• Ignoring the Problem: Many Houstonians dismiss AC maintenance as unnecessary. This is a dangerous gamble.
• Using the Wrong Filter: A cheap, low-MERV filter is practically useless against fungal spores.
• Improper Cleaning: Using harsh chemicals or neglecting to clean the coils thoroughly can worsen the problem.
• Self-Treating: Don’t try to diagnose or treat yourself. See a doctor.
• Waiting Too Long: Delaying medical attention can lead to serious complications.

Real-World Scenario:

Consider Mrs. Rodriguez, a 68-year-old Houston resident with COPD. She noticed a persistent cough and shortness of breath that worsened over the summer. Initially, she attributed it to her COPD and the Houston heat. However, her symptoms continued to worsen despite her usual medications. Her daughter, remembering a news report about pulmonary aspergillosis, urged her to see a doctor. After a chest X-ray and sputum culture, Mrs. Rodriguez was diagnosed with aspergillosis. Early diagnosis and antifungal treatment saved her from potentially severe complications.

Actionable Insights:

• Schedule AC maintenance reminders: Set recurring reminders on your phone or calendar to replace your AC filter and clean your coils.
• Invest in a high-quality filter: Don’t skimp on filter quality.
• Know your risk factors: If you have a pre-existing lung condition or a weakened immune system, be extra vigilant about monitoring your symptoms.
• Don’t hesitate to seek medical attention: If you experience any concerning symptoms, see a doctor immediately.

Living in Houston means embracing the heat and humidity, but it also means taking proactive steps to protect your health. By properly maintaining your AC system and recognizing the early symptoms of pulmonary aspergillosis, you can breathe easier and enjoy all that Houston has to offer. Don’t let Aspergillus steal your breath; take control and protect your lungs.