Where Is My AC Filter Located And How Do I Change It?

Updated August 14, 2025

HVAC Guides

Key Takeaways

Replacing the filter on your AC is a simple task, once you know how to find it.
The majority of AC systems hide their filters in either return ducts or inside the air handler.
Neglecting to replace your AC filter can reduce efficiency, raise energy bills, and damage system components.
Most filters should be changed every 1 to 3 months depending on usage and air quality.

A properly functioning AC system depends on one component most homeowners forget until problems appear: the air filter. If you have ever wondered where is my AC filter located and how do I change it you are not alone.

Even long-time homeowners sometimes struggle to find their filter, let alone replace it correctly. Knowing where to look and how to swap it out can prevent airflow restrictions, improve efficiency, and extend the life of your unit.

Locate and Change Your AC Filter

Every central air conditioning system relies on at least one filter to trap dust, pollen, and debris. These filters keep indoor air breathable and protect sensitive internal components.

Locating them requires a bit of familiarity with how your AC circulates air. In most modern homes, the filter sits in one of two primary locations: inside the return ducts or at the air handler itself.

Top 2 Places to Find Your AC Filter

The air filter is typically located near the thermostat in your home in a return duct. Or, it’s right next to your AC system’s air handler.

Return Ducts

One of the most common filter placements is in the return duct. Return ducts pull air from inside the home back into the system for cooling or heating. Look for large vent grilles on walls, ceilings, or occasionally at the baseboard. If the vent cover is larger than a typical supply register and secured with screws or latches, chances are it conceals the filter.

Many southern homes have multiple return ducts, especially larger floor plans. In such cases, each return may hold its own filter. Neglecting one means a portion of your system remains unprotected, so check all returns regularly.

Air Handler

The second most likely location is at the air handler. This unit often sits in attics, basements, closets, or garages.

The filter typically slides into a slot near the blower compartment, either behind a panel or within a dedicated filter rack. Because access may involve maneuvering in tighter spaces, it is wise to keep a flashlight and screwdriver on hand.

If you are unsure whether your air handler houses the filter, check for a removable door with airflow arrows marked nearby. These arrows indicate the correct orientation of the filter when reinstalled.

How to Change Your Air Filter

Once the filter has been located, replacement is relatively simple but should be done with attention to detail.

Turn off the system
Shut down your thermostat or flip the breaker to prevent the blower from running during the process.
Remove the old filter
Open the vent or panel, slide out the filter, and check its size. Most filters are clearly labeled with dimensions.
Inspect and confirm fit
Compare the old filter with the new one before installation. Using the wrong size can create gaps that allow unfiltered air to bypass the system.
Install with correct orientation
Look for airflow arrows on the filter frame. These must align with the system’s airflow direction, usually pointing toward the blower motor.
Secure and restart
Close the grille or panel, restore power, and reset your thermostat. Keep a reminder to check the filter monthly during peak cooling months.

Problems You May Face Changing Your Filter

Even a simple task like filter replacement can present challenges:

Hidden or multiple filters: Some homes have two or three filters scattered across returns and the air handler. Missing one reduces system protection.
Tight installation slots: Poorly designed compartments can make sliding filters in and out frustrating. Forcing them can damage the frame.
Wrong filter rating: High-MERV filters trap smaller particles but may restrict airflow if your system is not designed for them. This can stress the blower motor.
Neglected schedules: Forgetting to change filters leads to clogs. A clogged filter can cause coil freezing, uneven cooling, or even system shutdowns.

These problems highlight why consistent maintenance matters. Companies like Salas HVAC often recommend a professional inspection at least once a year to identify issues beyond filter care.

Why Proper Filter Maintenance Matters

The U.S. Department of Energy estimates that replacing a clogged filter can lower energy consumption by up to 15 percent. In hot climates where AC systems run nearly year-round, that savings adds up quickly.

Beyond cost, a clean filter protects the evaporator coil, improves indoor air quality, and keeps dust from circulating throughout the home.

For families dealing with allergies, pets, or frequent visitors, filters with a slightly higher MERV rating can provide noticeable relief.

However, it is always wise to confirm that your system can handle denser filters without compromising airflow.

Final Thoughts

Understanding where your AC filter is located and how to change it is a practical skill every homeowner in the South should have. It is not glamorous work, but it makes a measurable difference in comfort, air quality, and utility bills.

The next time your system runs longer than usual or air feels dusty, check your filter before assuming the worst. Consistent upkeep now can prevent expensive service calls later. And when in doubt, scheduling a professional tune-up with Salas HVAC ensures the entire system runs efficiently.

FAQs

How often should I change my AC filter?

Most standard filters should be changed every 30 to 90 days. Homes with pets or allergy concerns may benefit from monthly replacements.

Can I clean and reuse my AC filter?

Only washable or reusable filters are designed for cleaning. Disposable filters must be replaced with a new one each time.

What size filter does my system need?

Check the dimensions printed on the filter frame or inside the air handler compartment. Using the exact size prevents gaps and airflow issues.

What happens if I don’t change my AC filter?

A clogged filter reduces airflow, strains the blower motor, increases energy use, and can cause the evaporator coil to freeze.

Should I hire a professional to replace my AC filter?

Most homeowners can safely change their own filters. However, if you are unsure of the location or have multiple filters, a technician can confirm placement and provide maintenance tips.