Typical air vs. spike days
- Annual average PM2.5 (8.44 µg/m³) reflects usual daily exposure.
- Worst-day peak PM2.5 (28.65 µg/m³) is what filtration must handle during bad-air events.
Sections below reference one or both metrics on purpose — that is how HVAC vs. portable guidance differs for Florence without contradicting EPA-aligned thresholds.
Local Allergen Loads
Pollen and mold are the primary drivers of filter loading in Boone County. The Ohio River Valley is known for heavy spring tree pollen and fall ragweed cycles that put a massive strain on HVAC systems. These biological particles are much larger than PM2.5, but they clog filter media quickly, reducing airflow and increasing energy costs. Humidity levels in the region also contribute to mold spore activity. If you notice a musty smell when the air conditioning cycles on, it is often a sign that the evaporator coil or the filter itself has captured enough organic material to support growth. Keeping a fresh filter is the first line of defense against these seasonal loads.
Technician's Filter Recommendations
Based on a peak PM2.5 exceeding 25 µg/m³, I recommend a MERV 13 pleated filter for most modern HVAC systems in Florence. This rating is efficient enough to capture the fine combustion particles and smoke that make up PM2.5 spikes. However, MERV 13 filters are denser; if your system is older, we must ensure the static pressure does not rise too high and damage the motor. Given the ozone peaks of 0.0783 ppm, a filter with an activated carbon layer is a smart upgrade to help neutralize odors and gases that standard dust filters miss.
- Change filters every 60 to 90 days to maintain airflow.
- Inspect the filter every 30 days during peak pollen seasons.
- Consider a bedroom HEPA unit to supplement the central HVAC system.