How Often Should You Change Your AC Filter in Central Texas?

Quick answer: Check a standard 1-inch filter every month and change it when it looks gray and dusty, which in a Central Texas summer often means every 1 to 2 months. ENERGY STAR’s rule is simple: check it monthly and change it at least every 3 months. Thicker 4- to 5-inch media filters last longer, so follow the label and still check.

Why do Central Texas homes go through filters faster?

Because the AC here barely gets a day off. From roughly May through October the blower runs for hours a day, and every minute it runs, the filter catches something.

Local conditions add to the load. Cedar season fills the winter air with pollen, new construction kicks up dust in growing suburbs, and plenty of homes have a dog who sheds like it’s a job. If your air handler sits in the attic and the return side of the ductwork leaks, the system pulls attic dust straight toward the filter. Leaky ducts are a common reason one house clogs filters twice as fast as the house next door.

How can you tell when your AC filter needs changing?

Look at it. Switch the thermostat to OFF, slide the filter out and hold it up to a light. If you can barely see light through a 1-inch filter, it’s done. Other signs:

• The pleats have a gray or brown coat instead of their original color.
• The filter bows or sucks in toward the unit.
• Dust collects on the supply registers or around the return grille.
• You can’t remember the last change. Write the date on the frame with a marker next time.

Does filter thickness change how often you replace it?

Yes. A thin 1-inch filter has little surface area, so it loads up fast and usually needs changing every 1 to 3 months. A 4- or 5-inch media filter in a dedicated cabinet has far more pleated surface, and many are rated to last several months or longer. The manufacturer’s label is the guide, but check it anyway during a dusty summer.

Washable filters need rinsing on the maker’s schedule, and they must dry completely before going back in. A damp filter in a humid attic is an open invitation to mold.

Does a higher MERV filter need changing more often?

Often, yes. MERV is the 1-16 scale for how fine a filter catches. A higher MERV filter traps more fine particles, so it can fill up faster, and it starts out with more resistance to airflow. That’s why a MERV 13 filter jammed into a 1-inch slot on a basic system can cause more trouble than it solves. Our guide to MERV ratings walks through which rating fits which kind of system.

What happens if you leave a dirty filter in too long?

Airflow drops, and the rest of the system pays for it. With too little air moving across the indoor coil, the coil can get cold enough to freeze, and when that ice melts it can overwhelm the drain. See why an AC freezes up or leaks water for how that chain plays out.

A clogged filter also pushes more dust around its edges and onto the coil, which is much harder to clean than a filter is to replace. If your coil has already iced over or the drain has backed up, Gold Eagle’s AC repair team can clean the coil and clear the drain.

Where is the AC filter in an Austin home?

Usually behind a return grille in a hallway ceiling or wall. In others it slides into a slot at the air handler in the attic, a closet or the garage. Some homes have more than one return, each with its own filter.

If you find a filter at the grille and another at the unit, ask your technician whether you need both. Two filters in a row add resistance. When you slide a new one in, the arrow on the frame points toward the air handler, in the direction the air flows.

What should you do next?

• Find every filter in your home, at the return grilles and at the air handler.
• Check them monthly, and write the date on the frame each time you change one.
• In summer, plan on changing a 1-inch filter every 1 to 2 months.
• Book a Gold Eagle tune-up or call 512-489-4653, and ask your technician whether you need both filters if you have two in a row.

Related guides: What Are MERV Ratings, and How Do They Affect IAQ?, What’s Included in an HVAC Tune-Up? and Leaky Ducts: How They Pull Attic Air and Dust Into Your Home.

About Gold Eagle Services: This guide comes from the team at Gold Eagle Services, a family-run Austin HVAC, indoor air quality and mold remediation company founded in 2017. We’re licensed (TACLA119235 and RCO1783), insured and bonded, and we serve homes across the greater Austin area.

Need help with this in your home? Learn about our indoor air quality solutions, or call 512-489-4653 to schedule a visit.

Related Gold Eagle service: Home maintenance plan