Typical air vs. spike days
- Annual average PM2.5 (10.39 µg/m³) reflects usual daily exposure.
- Worst-day peak PM2.5 (39.23 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 Cypress without contradicting EPA-aligned thresholds.
Pollen and Humidity Load
Cypress residents deal with a heavy pollen load that acts as a physical burden on HVAC systems. Ragweed, oak, and cedar seasons are particularly aggressive in Harris County. These large biological particles often hitch a ride on the wind near the Cypress Creek Greenway, finding their way into return air ducts. Humidity also plays a major role here. High moisture levels can lead to mold spore proliferation within ductwork if the system is not cycling correctly or if the filter is restricted. This seasonal debris combines with indoor dust to create a thick mat on your filter, reducing airflow and forcing the blower motor to work harder than necessary.
Technician's Filter Recommendations
Given that PM2.5 peaks exceed 25 µg/m³ and ozone levels hit 0.0921 ppm, I recommend a MERV 13 pleated filter for most modern systems. A MERV 13 is dense enough to capture the fine combustion particles and smoke that contribute to those 39.23 µg/m³ spikes. However, because ozone is a gas, a standard filter will not stop it; you should look for a filter that includes an activated carbon layer to neutralize odors and chemical vapors. In the humid Harris County climate, filters can become loaded quickly. I advise checking your filter every 30 days and replacing it at least every 60 to 90 days. If you pull out a filter and it is dark grey or bowed inward, your system is struggling. For maximum protection during peak pollution days, supplement your HVAC with a standalone HEPA unit in high-traffic rooms.