How Often Should You Change Your AC Filter in Montgomery County?

Your AC ran hard all summer. Three months of 95-plus-degree days, the system cycling on and off for 12 to 14 hours at a stretch, pulling air through the same filter it has been using since June.

Now it is October. The windows are cracked for the first time in months. Temperatures are finally coming down. And most homeowners in The Woodlands and Conroe have not thought about that filter once since spring.

This is the right time to check it.

How Often Should I Change My AC Filter?

In Montgomery County, you should change your AC filter every 30 days during peak cooling season (May through August) and every 60 to 90 days during the fall and winter months when the system is running less. A home with pets, heavy pollen exposure, or anyone with allergies should stay on the shorter end of that range year-round.

That 90-day guidance you see on most filter packaging was written for average conditions in average climates. A home in southeast Texas running an AC system through a Gulf Coast summer is not average conditions. The filter fills faster here because the system runs more hours per day and because the air it is pulling in carries more humidity, dust, and allergens than cooler, drier climates.

If you have not changed your filter since before summer, change it now. If you changed it in June and forgot about it, change it now. That filter has likely been working at reduced capacity since August.

What Happens When You Leave a Filter in Too Long

A clogged filter does not just reduce air quality. It makes your system work harder to pull air through the blockage. That extra strain shows up in a few places.

Your energy bills run higher because the system is fighting to move air it should be moving easily. Your airflow drops, so certain rooms feel warmer or more humid than others even when the system is running. And over time, the additional strain on the blower motor and other components shortens the life of equipment that should last 15 years or more.

A $10 filter replaced on time protects a system worth several thousand dollars. That math is straightforward.

What MERV Rating Should You Use in a Texas Home?

MERV stands for Minimum Efficiency Reporting Value, which is the rating system for how well a filter traps particles. The higher the MERV rating, the more it catches, and the denser the filter material.

For most homes in Montgomery County, a MERV 8 to MERV 11 filter is the right range. It catches the allergens, dust, pet dander, and pollen that matter most in this climate without restricting airflow enough to strain the system.

MERV 13 and higher filters, which are marketed as hospital-grade or allergy-grade, catch more fine particles but also significantly reduce airflow. If your system was not designed with that restriction in mind, a very high MERV filter can cause the same airflow problems a dirty filter causes. More is not always better here.

If you have significant allergy concerns in your household, ask about it on your next service call. The right answer depends on your specific system and your ductwork.

Fall Is Also the Time to Check Your System for What Summer Left Behind

Changing the filter is the easy part. But October is also a good time to look at what three months of heavy use has done to the rest of the system.

The outdoor condenser coils can accumulate debris through the summer. The drain line may have algae buildup from months of condensate flowing through it. And if you have a heat pump or a gas furnace, this is the last chance to confirm it will start reliably before the first cold front comes through.

A system that cooled the house all summer without complaint can still surprise you in November if the heating side has not been checked. That startup after eight to ten months of sitting idle is when problems surface.

A fall maintenance visit covers all of this: filter check, drain flush, coil inspection, refrigerant check, and a test of the heating cycle before you need it. For plan members, this is your fall precision check. If you are not on a plan and want to get ahead of the season, call Tex Vet Air at (936) 718-8225 to schedule a fall tune-up before the first cold front.

Tex Vet Air Solutions, veteran-owned and serving Montgomery County since 2019. Don't sweat, call the vet.