Typical air vs. spike days
- Annual average PM2.5 (14.41 µg/m³) reflects usual daily exposure.
- Worst-day peak PM2.5 (81.96 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 Hanford without contradicting EPA-aligned thresholds.
Valley Dust and Filter Maintenance
Dust from the Kings River area and local agricultural activity creates a heavy physical load on home HVAC systems. This coarse dust often clogs filters long before they reach their rated lifespan. Seasonal pollen from valley vegetation adds another layer of biological material. This 'cake' of dust and pollen on your filter might seem to trap more particles, but it actually forces your HVAC system to work harder, increasing energy bills and potentially damaging the compressor due to restricted airflow.
Technician's Filter Recommendations
Given the extreme PM2.5 peaks in Hanford, I recommend a MERV 13 filter as the baseline for all homes. A MERV 13 is necessary to capture the fine particles that make up that 81.96 µg/m³ peak.
- Ozone Protection: Look for 'Dual-Action' filters that include activated carbon to handle the 0.0835 ppm ozone spikes.
- Replacement Schedule: Change filters every 60 to 90 days. If you notice the filter turning dark grey sooner, you have high infiltration and should check your window seals.
- Blower Motor Note: Ensure your HVAC system is rated for a MERV 13 filter; if the filter is too restrictive, it can cause the system to freeze up during peak summer heat.