Finding your air filter shouldn’t be a scavenger hunt. While it’s one of the simplest things you can do to maintain your HVAC system and improve your indoor air quality, many homeowners struggle to locate it. This guide will walk you through the most common places to find your air filter, turning a frustrating search into a quick and confident task.
Step 1: Start with the Most Common Spots
Most air filters are located in one of two places: either behind a large vent (known as a return air grille) or directly inside your main HVAC equipment (the furnace or air handler).
The Return Air Grille
This is the easiest place to check first, as it’s where roughly 70% of home filters are located. A return air grille is the large rectangular vent in your home that pulls air into your system. It will be noticeably larger than the smaller supply vents that blow cool or warm air into your rooms.
- Look for large vents on the wall, ceiling, or floor. In many Texas ranch homes, you’ll find these on a hallway wall. In two-story homes, they are often on the ceiling of an upstairs hallway. Homes on concrete slabs may have them on the floor.
- Check for airflow. A simple way to confirm you’ve found a return grille is to hold a piece of paper near it while your system is running. If the paper gets pulled toward the vent, you’ve found a return.
- How to access it. Return grilles typically open in one of three ways: with a latch system you can flip down, by removing one or two screws with a screwdriver or coin, or by pulling the entire grille straight out.
Important: Large Texas homes often have multiple return grilles, and each may have its own filter. Be sure to check all of them.
Step 2: Check Your HVAC Equipment
If you don’t find the filter behind a return grille, it’s likely located at your main heating and cooling unit. The indoor part of your system is a large metal box with ductwork attached. This is either an air handler (for central A/C) or a furnace (for heating).
Where to look on the equipment:
First, you’ll need to locate your air handler or furnace. In Texas, these are most commonly found in:
- Utility closets
- Garages (popular due to heat protection and space saving)
- Attics (common in both new and older homes)
- Basements or crawlspaces (more typical in older homes)
Once you’ve found the unit, look for a filter slot or an access panel. The filter is typically located where the return ductwork connects to the main unit, right before the fan blower.
- Look for a 1-inch thick slot on the side, bottom, or top of the unit. This is often covered by a removable or hinged panel.
- Search for a removable panel. Many units have a door or cover held in place with clips, latches, or screws that can be opened to reveal the blower fan and the filter rack.
- System orientation matters:
- Horizontal units (common in Texas attics) will often have a filter that slides into a rack on the intake side.
- Vertical units will have the filter sitting in a removable panel above or below the blower section.
Safety first: Always turn off your system at the thermostat or by using the electrical cutoff switch on the unit itself before opening any panels or changing the filter.
Step 3: Explore Less Common Locations
If you still haven’t found your filter, you may have an installation with a less common setup.
Ductwork filter access points
Some systems have a filter installed directly in the ductwork itself, rather than at a grille or the equipment. These are typically located near where the main return ducts connect to your air handler or furnace. Look for a rectangular panel built into the ductwork that appears to be removable, often held in place with clips or screws.
Window and portable units
If your home uses room air conditioners, they have their own filters.
- Window AC units: The filter is almost always located behind the front grille. You can usually access it by lifting or sliding off the front panel. These are often washable foam or pleated filters.
- Portable AC units: Look for an access panel on the front or side of the unit, usually behind the air intake grille.
Final Steps to Confirm Your Find
Once you think you’ve found the spot, there are a few things to check to make sure you’re in the right place:
- An existing filter: The easiest confirmation is finding an old, dusty filter inside.
- Perfect fit: Measure the length, width, and thickness of the opening. The filter you buy should fit snugly without being forced. Standard sizes are listed as length × width × thickness (e.g., 16×20×1).
- The airflow arrow: The arrow printed on the side of a new filter should always point toward the blower fan or the main unit, indicating the direction air is flowing.
When to Call a Professional
If you’ve searched everywhere and still can’t locate your filters, it’s time to call an HVAC professional. Some homes, particularly those with very old or custom systems, may have filters that are professionally serviced or may not use a standard replaceable filter at all (for example, with an electronic air cleaner). A technician can safely locate all your filters, map out your system, and provide a clear plan for future maintenance.
Regularly changing your air filter is the single most important maintenance task for your HVAC system. It helps reduce energy costs and extends the life of your equipment—a crucial step for keeping your Texas home comfortable all year round.
