The AC closet, where your air handler sits, is the number one place we find hidden mold in South Florida homes. If you’ve spotted dark spots, a wet floor, or a musty smell in there, here’s what’s going on and what to do.
Why the AC Closet Grows Mold
Your AC pulls gallons of water out of the air every day. That water drains through a condensate line. When the line clogs with algae and sludge, which is very common in Florida, water backs up into the drain pan and overflows onto the floor and walls. The closet is dark, warm, and enclosed, so mold grows fast and often stays out of sight.
Warning Signs
- Water in or around the drain pan
- Stains, swelling, or soft spots on the closet floor or walls
- Dark spots on drywall, the air handler, or vents
- A musty smell when the AC turns on
- Peeling paint or warped baseboards in the next room
What to Do
- Don’t scrub or bleach large areas. That can spread spores without fixing the cause.
- Have an AC technician clear the drain line and check the pan and coil.
- Get a mold inspection. The question is how far the moisture went: into the wall behind the air handler, under the floor, or into the next room.
- Have the mold removed properly with containment, especially if it’s more than a small spot. In Florida, jobs over 10 square feet require a licensed remediator.
- Prevent it next time: regular drain line cleaning, a float switch that shuts the AC off if the pan fills, and keeping indoor humidity under about 60%.
Free Inspection From a Licensed Mold Company
FL Cleanup is a Florida-licensed mold assessor (MRSA4035) and remediator (MRSR4158). We offer a free visual inspection of the closet and surrounding walls with moisture readings and an infrared (thermal) camera, and if the smell lingers after the fix, our whole-home odor treatment runs through the AC system and every room ($997, odor only). Call 877-224-2532. Hablamos español. More: Why does my AC smell musty?
