Typical air vs. spike days
- Annual average PM2.5 (8.92 µg/m³) reflects usual daily exposure.
- Worst-day peak PM2.5 (31.37 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 Burleson without contradicting EPA-aligned thresholds.
Seasonal Pollen and Filter Load
Pollen and mold are the primary drivers of filter clogs in Johnson County. The proximity to the Chisholm Trail Parkway and local grasslands means cedar, ragweed, and oak cycles are intense. These large biological particles don't just affect your sinuses; they physically coat the surface of your HVAC coils and filters. When humidity rises, mold spores become a secondary concern. This seasonal load creates a thick layer on the filter media, reducing airflow and forcing the blower motor to work harder. It is common to see filters that look clean to the naked eye but are actually restricted by fine, invisible pollen particles that have saturated the fibers.
Technician Filter Recommendations
Because PM2.5 peaks exceed 25 µg/m³ and ozone hits 0.0807 ppm, I recommend specific filtration strategies for local homes:
- MERV 13 Pleated Filters: Recommended for most modern systems to capture the fine particulates seen during worst-day spikes without severely restricting airflow.
- MERV 11 Baseline: If your HVAC unit is older or has a smaller return, use a high-quality MERV 11 and supplement it with a standalone HEPA unit in the main living area.
- Activated Carbon: For homes sensitive to ozone spikes, look for filters with a layer of activated carbon to help neutralize odors and chemical irritants.
Given the local dust and pollen load, these filters should be inspected every 30 days and replaced every 60 to 90 days. If the filter looks gray or feels heavy, it is already restricting your airflow and costing you money in energy bills.