Typical air vs. spike days
- Annual average PM2.5 (8.10 µg/m³) reflects usual daily exposure.
- Worst-day peak PM2.5 (32.50 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 Harvey without contradicting EPA-aligned thresholds.
Pollen and Moisture Load
Local air filters in Harvey face a heavy load from organic debris. Proximity to the Harvey Canal and surrounding lowlands leads to high mold spore counts, especially after heavy rains. Seasonal tree pollen and grass allergens are prevalent, often appearing as a fine dust on outdoor surfaces. When this material is pulled into your HVAC system, the high humidity can cause it to clump, which quickly clogs standard filters. This not only degrades air quality but also puts unnecessary strain on the blower motor, leading to higher repair costs over time.
Professional Filtration Advice
Given the peak PM2.5 levels of 32.5 µg/m³, I recommend a MERV 13 pleated filter for the city homes. This rating is designed to capture the microscopic particles that characterize local air spikes. If you find that a MERV 13 restricts your airflow too much, a MERV 11 is the minimum baseline I suggest for this region. To keep your system running efficiently, follow these technician-level tips:
- Inspection: Check your filter every 30 days. The high humidity in the city can cause filters to load faster than the manufacturer's rating suggests.
- Replacement: Swap the filter every 60 to 90 days. Never let a filter run for a full year.
- Carbon Options: If you are sensitive to the 0.0706 ppm ozone peaks, consider a filter with an activated carbon layer to help neutralize odors and gases.