Why it matters to you
In Greater Houston the system runs long hours for most of the year, so filters load up faster than the calendar suggests. A clogged filter restricts airflow, raises static pressure, and can contribute to a frozen coil or a dirty, less efficient system.
Practical guidance
Turn the system off at the thermostat, then check the filter monthly in summer and replace it when it looks gray or loaded, matching the exact size printed on the frame with the airflow arrow pointing toward the equipment. If you're unsure where your filters are, or how many there are, ask your technician to show you during maintenance.