Musty smell from AC vents
Answer: call a hvac technician.
A musty or mildew smell blowing from AC vents usually signals mold or bacteria growing inside the HVAC system — on the evaporator coil, in the drain pan, within ductwork, or on a clogged air filter. Beyond being unpleasant, airborne mold spores can aggravate allergies, asthma, and respiratory conditions. An HVAC technician can inspect the system, clean the evaporator coil and drain pan, treat ductwork, and identify root causes like poor drainage or inadequate dehumidification.
Who to call
For this problem, call a: HVAC Technician
Symptoms to look for
- Damp or musty odor when the AC first turns on
- Smell gets worse on humid days or after the system sits idle
- Visible black or green growth on vent grilles
- Family members experience increased allergy or sinus symptoms indoors
- Condensation or water dripping near the indoor air handler