Mold in Your HVAC System? Don’t Panic—Let’s Make a Plan
In Southern Coastal Virginia, where humidity is part of daily life, the presence of mold in HVAC systems is more common than you might think. But here’s the good news: it’s manageable, preventable, and doesn’t mean your system is doomed. At Keystone, we've recently seen an uptick in mold-related service calls—and we’re here to help homeowners understand what’s normal, what needs attention, and how to take control.
Understanding Common Causes and Locations of Mold in HVAC Systems
HVAC systems, especially in humid climates, can become breeding grounds for mold if not regularly maintained. Mold thrives in dark, moist environments—making your ductwork, evaporator coils, and drain pans particularly susceptible.
Signs You Might Have Mold in Your HVAC System
Musty odors when your system turns on
Dark spots around vents or air registers
Increased allergy symptoms like sneezing, headaches, or eye irritation
Top Areas Where Mold Forms
Air Ducts – Temperature differences can cause condensation, which supports mold growth. Regular duct cleaning can help prevent buildup.
Evaporator Coils – These naturally collect condensation and need regular maintenance to avoid mold.
Drain Pans – If clogged or not draining properly, they can hold standing water and create ideal mold conditions.
Filters – Damp or dirty filters not only reduce airflow but can also harbor mold spores.
How to Get Rid of Mold in Your HVAC System
If you suspect mold, it’s important to act quickly. Mold can begin forming in as little as 48 hours under the right conditions. Here’s what a professional cleaning process might look like:
Turn off your HVAC system
Use proper PPE (like N-95 respirators)
Replace any porous materials such as filters or wet insulation
Use wet vacuums and HEPA vacuums for dry areas
Disinfect non-porous components with EPA-registered products like BIOSPRAY-TOWER
Clean coils mechanically to remove debris
Seal off cleaned sections with bladders and fog with disinfectants
Apply long-term mold inhibitors (like BBJ Mold Control)
Final vacuum with HEPA to remove remaining particles
What You Can Do to Prevent Mold
Schedule regular HVAC maintenance
Maintain indoor humidity between 30% and 50%
Check and change your air filters monthly
Ensure your system drains properly
Consider installing UV air purifiers for additional protection
Let’s Tackle It Together
Mold in your HVAC system doesn’t have to be a crisis. With a solid plan, professional support, and preventative care, your home can stay cool, comfortable, and mold-free.
If you’ve noticed musty odors or suspect mold might be growing in your ducts or coils, give Keystone a call at 757-344-4010. We’ll walk you through the next steps with care, clarity, and confidence.
If you're concerned, just take a look at the mold on this wall in an abandoned apartment complex one of our estimators recently found—it's a reminder of what can happen when systems go unchecked.