Typical air vs. spike days
- Annual average PM2.5 (8.85 µg/m³) reflects usual daily exposure.
- Worst-day peak PM2.5 (31.82 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 Palatine without contradicting EPA-aligned thresholds.
Seasonal Loads and Filter Wear
Regional pollen and mold patterns create a hidden load on your HVAC system. Proximity to the Deer Grove Forest Preserve means heavy tree pollen in the spring and significant weed pollen in the late summer. Mold spores also become a factor during humid Illinois summers. These biological particles are larger than PM2.5 but are much stickier, often clinging to the cooling coils if the filter is not seated correctly. This seasonal debris, combined with standard household dust, can restrict airflow and increase energy costs if the filter is not monitored during peak seasons.
Technician's Filter Recommendations
Because Palatine sees PM2.5 peaks exceeding 25 µg/m³, I recommend using a MERV 13 pleated filter. Standard MERV 8 filters are designed to protect the equipment from large dust bunnies, but they fail to capture the fine combustion particles and smoke that characterize local pollution spikes. Since ozone peaks reach 0.081 ppm, you should also consider a filter with an activated carbon layer to help neutralize gases and odors. Change your filters every 60 to 90 days. If you have pets or high foot traffic, check them every 30 days during the summer and winter when the blower motor runs most frequently. A clogged filter doesn't just stop cleaning the air; it puts unnecessary strain on your heat exchanger and compressor.