Musty smell from AC vents — San Francisco, California
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.
Waarom dit veel voorkomt in San Francisco
The cool, foggy maritime climate means central AC is rare and rarely needed, so HVAC work centers on heating efficiency, ventilation, and increasingly heat-pump retrofits driven by Title 24 energy rules. Older homes often have undersized or outdated heating systems requiring careful upgrades.
Who to call
For this problem in San Francisco, call a: Klimaattechnicus
Vind een Klimaattechnicus in San FranciscoSymptoms 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
Spoeddienst in San Francisco
Emergency home services in San Francisco are available 24/7 at premium rates — expect $150–$300+/hour for after-hours plumbing or electrical, the highest tier in the US. Response times average 45–90 minutes given hilly terrain and parking scarcity. Always verify an active CSLB license and proper DBI permits.