How do I change my HVAC filters?

Homeownership is exciting and comes with maintenance responsibilities, like cleaning gutters, mowing the lawn, and changing HVAC filters. The latter is what we are going to discuss here today.

Why Regular Filter Changes Matter More Than Ever in 2025

With HVAC systems accounting for approximately 40% of the total energy used in commercial buildings and nearly half the energy in residential homes, maintaining clean filters has never been more crucial for both your wallet and the environment. A clogged filter causes systems to use 15 percent more energy, according to the U.S. Department of Energy, which can significantly impact your utility bills in today's rising energy market.

The general recommendation for how often to change hvac filters is once a month, and many homeowners will replace the batteries in their smoke detectors at the same time. This regular maintenance step will ensure that the air conditioner or HVAC system is working at top condition without having to work harder than necessary.

Market Growth and System Efficiency in 2025

According to recent industry analysis, there will be more than 151 million HVAC systems supplied worldwide in 2024, with the industry projected to see annual growth of 7.4% in its market share from 2024 to 2030. As systems become more advanced, proper filter maintenance becomes even more critical to maintaining their efficiency and warranty coverage.

Preparing To Change Your HVAC Filter

Replacing a furnace filter is easy, but if it’s your first time, start by checking the owner's manual for specific instructions. This will help you identify the correct filter size and shape—important details that vary by system. For older homes without a manual, you can determine the right filter by inspecting the one currently in use

Also, if you do not follow the recommendations given by the manufacturer, you could be voiding any warranty or any HVAC warranty plans that may have come with the unit and your home. The owner's manual should also advise you how to change the HVAC filter, but if not, we offer the following general instructions:

How To Change An HVAC Filter: Step-by-Step Guide

1. Turn the HVAC system off before you begin.
2. Locate your filter. Looking at the ductwork, you will be able to determine the furnace filter location. If you have an AC window unit, you'll need to pull open or remove the front grill and further directions may vary a bit, but in general, they are the same.
3. Understand your system. Every HVAC unit works generally the same way: Outside air is pulled in and blows out through the filter after being cooled or heated, and then blown into your home. The HVAC filter is situated in between where the air comes in and where it goes back into the system via the ductwork.
4. Remove the old filter. Once you locate the filter, if you haven't found what shape, size or type of filter is required, you can look at what is on the current filter. Be sure to make a mental note or take a picture with your cell phone on how it comes out. You'll need to know this when installing the new one. You want to purchase the same shape and size, and when it comes to types, you may want to change it if anyone in the house has allergies.
5. Install the new filter. Now you will take the new filter you've purchased and slide it in where the old filter came out. Make sure you have it in the right direction, meaning, one side of the filter is made to suck in that outside air and one side is made for that air to blow back out. (This is where the recommendation to take a picture will come into play).
6. Close and restart. Now close the access panel and turn the HVAC system back on. Grab your favorite beverage and sit back to enjoy that clean air you get from this homeownership maintenance responsibility!

What About Cleaning Those Filters?

There are reusable filters for air conditioners and HVAC systems these days. They are more expensive to purchase, but they are reusable because they can be washed and returned to the system, thus getting your money's worth.

Here Is How To Clean AC Air Filter

A window AC unit filter is much easier to get to than an HVAC system. You simply, but carefully, pull off the front grill and the filter will either snap out or is pulled up or down. Rinse it with nothing but clear water in the bathtub, kitchen sink, or outside with a water hose. Allow it to stand upright where it can dry then return it, following the same steps in reverse.

Here Is How To Clean HVAC System When Filter Is Reusable

After you have removed the filter through the access panel as instructed above, simply run clear water through it in the bathtub, kitchen sink, or in the yard with a water hose. You want the water to have force, but not too strong as to rip a hole through it. Then set it someplace where it can dry, and then return it to the HVAC system.

The Hidden Cost of Neglecting Filter Changes

A dirty filter not only spikes your energy consumption by up to 15% but can also compromise the longevity of your system due to increased wear and tear. With up to 3 million heating and cooling systems being replaced every year in the U.S., proper maintenance through regular filter changes can help extend your system's lifespan and avoid costly replacements.

Professional Coverage Options

If you have a home warranty plan, like those offered by Liberty Home Guard, check with your policy to see if filter changing or cleaning is covered by the policy before you begin. If not, you should inquire how you can get full HVAC coverage that does offer this service.