The Right AC Filter Schedule for Fort Smith's Pollen Seasons

Filter packaging says "change every 90 days." That number was not written for the River Valley. Between Ozark tree pollen in spring, grass pollen all summer, ragweed in fall, cottonwood fluff matting itself into everything in May, and humidity that turns ordinary dust into caked-on grime, Fort Smith filters work harder than most.

The Fort Smith Filter Calendar

• March-May (tree pollen + cottonwood): check monthly, expect to change monthly
• June-September (grass pollen + peak humidity): monthly changes, no exceptions — this is peak cooling season
• October-November (ragweed): check monthly
• December-February: every 60-90 days is usually fine

Why Humidity Makes It Worse

A dry filter traps dust loosely. A filter in humid River Valley air collects dust that cakes into a solid mat — airflow resistance climbs faster, and the system strains. The first symptom is usually a frozen coil or a system that runs constantly without quite reaching the set temperature. Both are expensive ways to learn your filter was overdue.

Picking the Right Filter

For most Fort Smith homes, a MERV 8-11 pleated filter is the sweet spot — fine enough to catch pollen and dust, open enough not to strangle airflow. Higher MERV ratings aren't automatically better: a MERV 13 in a system with undersized returns can starve the blower and freeze the coil. If anyone in the home has allergies, fix the schedule before upgrading the filter — a fresh MERV 8 beats a three-month-old MERV 13 every time.

Pets, recent renovation dust, and households near active construction (looking at you, Chaffee Crossing) should all shorten the schedule a notch. Not sure what your system needs? Ask us at your next tune-up — we'll check your return sizing and give you a straight answer.