Typical air vs. spike days
- Annual average PM2.5 (9.64 µg/m³) reflects usual daily exposure.
- Worst-day peak PM2.5 (30.88 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 Addison without contradicting EPA-aligned thresholds.
Local Allergen Loads
Seasonal shifts bring a heavy load of pollen and mold spores to Du Page County. Proximity to the Salt Creek Trail and local forest preserves means high concentrations of oak, maple, and ragweed pollen depending on the month. These biological particles are much larger than PM2.5, but they clog filters just as effectively. Humidity in the summer also promotes mold growth, which can enter the home and settle in the ductwork if the filtration system is not maintained properly. These seasonal elements represent the hidden load that wears down HVAC efficiency.
Technician Filter Recommendations
Because PM2.5 peaks exceed 30 µg/m³ and ozone hits 0.0809 ppm, I recommend a MERV 13 pleated filter. A MERV 13 is dense enough to capture the fine particulates seen during those peak days without overly restricting airflow in most modern furnaces. Since ozone levels also spike, consider a filter with an activated carbon layer to help neutralize odors and gases. Change these every 60 to 90 days. If you notice heavy dust on your return vents or if it is a high-pollen spring, check the filter at the 45-day mark. A clogged filter does not just stop cleaning the air; it puts unnecessary wear on your blower motor and increases energy costs.