Mold in Air Ducts and AC Vents in Sulphur, LA
If the house smells musty the moment the air conditioning starts, or the vent covers keep growing dark spots, the problem is probably in the duct system rather than the room.
Mold in air ducts in Sulphur usually comes from condensation. Summer dew points average 72.6–74.4°F (NOAA), well above the temperature of air leaving an AC coil, so vents, boots and ducts sweat. Duct and air handler cleanup runs $1,000–$4,000 in the Lake Charles area, and the condensation has to be fixed too.
Why do ducts sweat in Sulphur?
An air conditioner sends out air in the 50s. The attic or wall space around a duct is much warmer than that, and in summer the air there holds a lot of water: NOAA's hourly normals for Lake Charles put average dew points at 72.6°F in June, 74.4°F in July and 74.0°F in August. Anywhere a cold duct meets that air without a tight seal and good insulation, water beads up. Dust sticks to the wet metal or flex liner, and mold follows.
Signs your ducts have mold
- A musty smell each time the AC starts.
- Dark specks or fuzz on supply registers that come back after cleaning.
- Water stains on the ceiling around a vent.
- A drain pan under the air handler that holds water, or a condensate line that keeps clogging.
- Allergy symptoms that get worse indoors when the system runs.
How duct mold gets fixed
- Inspect the air handler, coil, drain pan and a sample of supply runs.
- Clean or replace. Sheet-metal ducts can usually be cleaned; moldy flex duct and duct board are usually replaced.
- Clean the coil and pan, and clear the drain line.
- Fix the cause: seal and insulate ducts, repair torn insulation jackets, and check that the AC runs long enough to pull moisture out of the air. An oversized unit that short-cycles cools the house without drying it.
After a storm or flood
Ducts that ran through a flooded house, or through an attic that got wet when a roof failed, can hold moisture and debris long after the rooms are dry. Delta caused significant flash flooding in Calcasieu Parish in October 2020 (NHC). If your system was never opened after water damage, it's worth a look. Ranges for this and every other job are on the Sulphur mold removal cost page.
Questions homeowners ask
Is duct cleaning enough to get rid of mold?
Not by itself. Cleaning removes the growth, but if the ducts keep sweating, it returns. The lasting fix pairs cleaning or replacement with sealing, insulation and a drain line that works.
Can I just spray something into the vents?
Foggers and vent sprays don't remove growth from inside ducts or the coil, and some aren't meant to be breathed. If a register keeps growing mold, the duct behind it needs to be inspected and cleaned or replaced.
Ask for a mold inspection in Sulphur
Describe what you're seeing or smelling. A local mold specialist who works in Sulphur will phone you to pick a time.