While the rest of the country is shoveling snow, we’re here in Florida enjoying open windows and mild temperatures. However, this is exactly when many of us accidentally create the perfect environment for HVAC mold. Weather fluctuates between chilly mornings and 75-80 degree afternoons… This means your system is facing more unique challenges than in summer!
During the hottest months, your AC runs constantly, which means it is always pulling moisture out of the air. In winter, we often turn the system off to "let the house breathe." The result? Stagnant air and rising indoor humidity. When the sun hits your roof in the afternoon, your attic warms up, and if your HVAC isn't circulating, that trapped moisture settles in your ducts—the perfect "petri dish" for mold spores.
Mold Prevention Checklist
- The "15-Minute Rule" for Open Windows
- We all love the cool breezes, but leaving windows open all day invites Florida’s 70%+ outdoor humidity inside.
- The Strategy: Enjoy the fresh air for a short burst, then close the windows and let your HVAC run for at least 15–20 minutes to "wring out" the moisture you just let in.
- Don't Let the "Auto" Fan Fool You
- When it’s not hot enough for the cooling cycle to kick on, your system’s fan often stays still.
- The Fix: Switch your thermostat fan setting from "Auto" to "On" for a few hours a day. This keeps air moving through your filters and prevents moisture from pooling in the dark corners of your ductwork.
- Check for Condensation
- January, February and even March can bring a temperature differential (cooler nights, warmer days). This can cause condensation to form on the outside of your vents or on the windows.
- Pro Tip: If you see "sweat" on your metal vents, it means your indoor humidity is too high (likely over 60%). Aim to keep your indoor humidity between 30% and 50% even during these cooler months.