Typical air vs. spike days
- Annual average PM2.5 (8.37 µg/m³) reflects usual daily exposure.
- Worst-day peak PM2.5 (45.17 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 Eagle without contradicting EPA-aligned thresholds.
Local Allergen Load
Seasonal pollen and fine dust act as a hidden load on your HVAC filters. In this region, sagebrush and various grasses contribute heavy biological matter to the air, particularly near the Boise River corridor. This organic debris accumulates on the damp surfaces of your cooling coils, which can lead to mold growth if the filter is bypassed. The semi-arid climate also ensures that fine mineral dust stays suspended in the air longer than in more humid environments. This constant cycling of grit through your blower motor can lead to premature mechanical wear if your filtration is not dense enough to trap fine particles.
Technician's Filter Recommendation
Based on the PM2.5 max of 45.17 µg/m³, I recommend using a MERV 13 pleated filter. A MERV 13 is necessary to capture the fine smoke and dust particles that characterize the area's worst-air days. Because ozone peaks reach 0.0771 ppm, you should specifically look for a filter that includes an activated carbon layer. This helps neutralize gaseous pollutants and odors that standard filters cannot touch. In local homes, filters should be changed every 60 to 90 days. The combination of fine valley dust and seasonal pollen will restrict airflow faster than the manufacturer's generic ratings suggest. If you notice your AC running longer cycles or see dust buildup around your supply vents, the filter is likely at capacity and needs immediate replacement to protect the blower motor.