Typical air vs. spike days
- Annual average PM2.5 (12.34 µg/m³) reflects usual daily exposure.
- Worst-day peak PM2.5 (35.98 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 Pomona without contradicting EPA-aligned thresholds.
Local Allergen Load
Seasonal pollen and mold cycles add a heavy physical load to HVAC systems in the area. Being situated near the base of the foothills means wind patterns often trap dust and biological allergens against the slopes. This creates a filter-clogging effect where even if the PM2.5 is low, your filter is still getting hammered by larger biological particles. This constant accumulation reduces the efficiency of your blower motor and can lead to higher energy bills if the filter is not maintained.
HVAC Filter Recommendations
For Pomona homes, I suggest a MERV 13 pleated filter. The PM2.5 max of 35.98 µg/m³ is too high for basic MERV 8 filters to handle effectively. You need the tighter weave of a MERV 13 to trap the fine particulates that the city experiences during peak events.
- Use filters with an integrated carbon layer to reduce irritation from high ozone peaks (0.0917 ppm).
- Replace filters every 60 days during the high-use summer and winter months.
- Do not exceed 90 days between changes to avoid damaging your blower motor due to restricted airflow.