San Antonio averages 80 days per year with relative humidity above 90 percent, most of them concentrated between May and September. That sustained moisture exposure saturates evaporator coils and creates ideal conditions for mold and mildew. When your system cycles off during cooler evening hours, condensation sits stagnant in the drain pan and ductwork. By morning, biofilm starts forming. Over weeks and months, that biofilm spreads across coil fins and into supply ducts, releasing musty odors every time your blower runs. The problem intensifies in poorly insulated attics where radiant heat from the roof deck keeps ductwork warm enough to prevent condensation from evaporating naturally.
Local HVAC contractors who understand San Antonio's climate design systems with proper dehumidification capacity and recommend coil cleaning schedules that match local conditions. National chains and inexperienced technicians often overlook these details, which is why odor complaints spike every spring and fall when temperature swings create condensation cycles. Patriot HVAC has built a reputation across Bexar County for solving odor problems that other companies misdiagnose or ignore. We know the building codes, the soil conditions, and the seasonal patterns that affect indoor air quality in every neighborhood we serve.
