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 Westwego without contradicting EPA-aligned thresholds.
Biological and Seasonal Loads
Being situated near the Mississippi River and local bayous, the area faces unique biological challenges. Humidity is the biggest driver of indoor air issues here, as it promotes mold growth and keeps dust mites active. Seasonal pollen from cypress and oak trees adds a heavy physical load to HVAC filters. These larger particles might not show up on PM2.5 monitors, but they are the primary cause of system efficiency loss. When pollen and moisture mix on a dirty filter, it creates an environment for odors and microbes to flourish. Keeping a fresh, dry filter in the rack is necessary for managing this regional load and protecting the longevity of your air conditioning equipment.
HVAC Technician Filter Guide
For homes in this area, a MERV 13 filter is the professional choice. Since PM2.5 spikes hit 32.5 µg/m³, a MERV 13 is necessary to trap those smaller particles that a standard MERV 8 would miss. If you find that a MERV 13 restricts your airflow too much—evidenced by a whistling sound or the AC freezing up—drop down to a MERV 11. To address the ozone peaks of 0.0663 ppm, I suggest using a filter with an integrated carbon layer. Carbon is specifically designed to adsorb gases and odors that standard pleated material cannot catch. Because of the local humidity and pollen counts, check your filter every 30 days and replace it at least every 60 days. A clogged filter in this climate doesn't just work poorly; it can lead to expensive evaporator coil cleanings and reduced system lifespan. Consistent replacement is the most cost-effective way to maintain air quality.