Where Is My Furnace Filter Located?

Sep 17, 2024

Maintaining enough airflow and avoiding damage to your HVAC system are the two main reasons to replace your furnace filter. Your HVAC system has to work harder to move air when the filter is blocked. By changing the filter regularly, you and your family can live in a healthier home with better indoor air quality.

What is a Furnace Filter?

The part of your heating, ventilation, and HVAC system called a furnace filter captures airborne particles as they pass through the system, including dirt, pollen, dust, pet dander, and other particles. The filter, which is located between the furnace and the return air duct, protects the HVAC system's parts by preventing debris build-up and improving air quality. Where your furnace filter is located depends on how your furnace was installed.

Furnace Air Filter Location

The location of your air filter depends on the type of AC unit in your house. While most furnace filters can be found in the blower of the furnace, you must be able to find your furnace or AC unit first. Whether you are moving into a new home or you always let the technician handle the job during annual tune-ups, you should know how to locate the air filter in your home. Good news – we're here to give you a few ideas.

Where Is My Furnace Filter?

Your furnace filter will most likely be found in the blower of your furnace. Where the blower is depends on how the furnace was installed.

Horizontal HVAC unit - Furnace filter will be located on the intake side, slid into a rack.
Vertical HVAC unit with air moving upwards - You can find your furnace filter in the bottom door. This is where the blower is. You will need to open both the top and bottom doors to get to the filter.
Vertical HVAC unit with air moving downwards - Your air filter will be in the top door, where the blower is located. This type of furnace or AC unit will most likely require two filters.

Also, to find the furnace filter location, look in one of the following places within your HVAC system:

Return Air Vent: In certain HVAC systems, the filter is behind your home's return air vent, which draws air into the system. It’s usually found on a floor, wall, or ceiling.
Furnace Blower Compartment: The filter is often positioned close to the furnace's blower. Look for a slot where the filter slides in and out, typically between the air intake duct and the furnace.
Air Handler: The filter is frequently located in the handler unit, near the return duct, in systems with a separate air handler.

If you can’t locate it and want to know where to find the furnace filter, follow the airflow path from the return vent to the furnace or air handler. Filters are usually easy to access and replace. If you're unsure, a professional technician should be able to show you how to find a furnace filter, or you can review your HVAC manual.

Where Is My AC Filter?

Are you scrambling around your home to find where is the air filter located? Locating your air conditioning filter isn't always easy, especially in a bigger home. In fact, some larger homes have multiple locations for AC filters, and all your filters should be changed regularly. Below are some of the most common places to look:

Central air return register/vent - If your home has one large central return register rather than one per room, check there for the filter. Central return registers are most often situated in an open common area such as the top of a stairwell, in the floor, or in the hallway ceiling. The filter should be located just inside the grill, which you can remove with a screwdriver. Also, the filter is probably located on a wall, ceiling, or floor beneath the return air vent. Your HVAC system uses the vent to draw in air for heating or cooling.

Air handler - In homes with multiple return registers, the filter is often installed immediately in front of the air handler. This component is most likely located in either the attic, garage, or basement. In most apartments, the AC unit is in a small closet, and the furnace filter should be within arms' reach. Look for a long, narrow slot with a removable cover. The filter should be inside. In central air systems, heating and cooling have one filter that operates all year. To replace an air filter, look for it next to the air intake duct or in front of the air handler.
Furnace Blower Compartment: The filter might be located near the blower compartment, between the furnace and air return duct, in systems that share parts with the furnace.
Ceiling or Wall-Mounted Unit: In a ductless mini-split system, open the front panel. The filter is found inside the interior unit.

If you cannot locate the furnace filter after following these tips, ask a local technician for help the next time you have your furnace tuned up. They can help you find the furnace filter and show you how to replace it. This way, you can perform this task yourself based on the recommended schedule of every 30 to 90 days without bringing a professional in for help.

Trace the airflow path from your home into the system to find your AC filter. You can also look in your system manual for info on where to find it.

How to Locate Your Furnace Filter?

If you’re wondering where the furnace filter is located, identify the return air duct that pulls air from your home into your HVAC system. It might be behind the return air vent. If not, check the furnace to see if it's in a slot near the blower compartment between the return duct and the furnace. The filter may be located inside the air handler unit if your HVAC system has one. If you still can’t find it, ask a professional to help you or read your manual. Your home's air quality depends on the furnace filter being changed regularly.

Can Furnace Filters Be Installed in Any Direction?

Furnace filters can’t be installed in any direction; they have to be installed correctly to work the right way. They have an airflow direction arrow printed that shows the direction air should flow. As it moves from the return duct into the system, this arrow should point in the direction of the furnace or air handler.

Improper filter installation limits airflow, reduces efficiency, and causes the system to work harder, raising utility bills and wearing down your system. Check the airflow arrow and follow the manufacturer’s instructions to ensure your filter is correctly installed. If you aren’t sure, call a professional to help you.

How Do You Know When It’s Time to Change Your Furnace Filter?

Knowing when to change your furnace filter depends on what type of filter it is, your system usage, and your home. Standard filters should be replaced every 1–3 months, while higher-efficiency filters could last from 6–12 months. It’s time to change the filter if you see visible dirt or dust buildup on it, reduced airflow from vents, or an increase in dust in your home. If you’re running your HVAC system more often during winter or summer, or you have pets or allergies, you might need to replace the filter more often. Routinely checking the filter for dirt can help maintain the highest level of system performance.

Conclusion

To ensure your furnace and HVAC system operate properly, change your filter often. Check for dust and dirt around it on a regular basis. Air Filters Delivered has a wide variety of furnace filters in many standard sizes and types to meet your needs. We also build custom filters. Replacing your furnace filter is a small investment that protects your family’s health and ensures your HVAC system and furnace are protected.

Now that you have finally found your furnace filter, you can teach yourself how to change your air filter and start changing your filter as often as you should.

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