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 Claremont without contradicting EPA-aligned thresholds.
Seasonal Dust and Pollen Loads
Seasonal allergens and dust are a constant load on local HVAC systems. The geography near the San Gabriel Mountains contributes to specific wind patterns that move pollen and mold spores through the community. These biological particles are significantly larger than PM2.5 but are produced in massive volumes during the spring and fall. They act as a pre-filter on your HVAC system, often clogging media faster than expected. When these filters become loaded with organic material, they can become a source of odors and reduced airflow, which puts unnecessary stress on the compressor and fan motor.
HVAC Filter Recommendations
For Claremont homes, a MERV 13 filter is the baseline recommendation due to PM2.5 peaks exceeding 35 µg/m³. This level of filtration is necessary to trap the fine particulates that standard MERV 8 filters ignore. Because ozone peaks are also high at 0.0917 ppm, I recommend a filter that incorporates activated carbon. Carbon is specifically designed to adsorb gaseous pollutants like ozone, which a standard pleated filter cannot do.
Technician's Tips:- Filter Changes: Swap your MERV 13 filter every 60 to 90 days. If you notice a whistling sound from your vents, the filter is likely restricted and needs immediate replacement.
- System Check: Ensure your HVAC system is rated for MERV 13. If the blower motor seems to be struggling, drop back to a MERV 11 and use a portable HEPA unit in the main living area.