Regularly changing your air filter is one of the simplest DIY tasks you can do to extend your HVAC system’s longevity, lower your energy bills and enjoy better air quality in your home. But how often should you do so? There’s no one-size-fits-all answer to this question.

Most air filter manufacturers recommend changing them every three months. While this is a good general rule of thumb, various factors may extend or shorten your filter’s lifespan. For instance, if anyone in your household has allergies or other respiratory issues, you might need to swap your air filter monthly. In contrast, if you rarely need to run your heating and cooling system, you could go upwards of six months to a year without needing to change the HVAC filter.

What Affects the Lifespan of Your HVAC Air Filter?

Most homeowners are glad to learn tips for having a cleaner home and saving money on their utility bills. Regularly changing your HVAC filter can provide both these benefits simultaneously. However, even if you’ve been diligent about proactively replacing your filter every three months, that might not be enough. Consider the factors below to help you determine if you need more frequent changes.


Dogs and cats bring unconditional love to your family, but they also shed their fur on your floors, furniture and clothes. If you have one or more furry family members, consider replacing your HVAC air filter every one to two months – especially in early fall and spring, when shedding is at its peak.


You’ll also want to replace your air filter more often if you have young children. While kids’ immune systems are still developing, they’re more prone to catching colds and respiratory infections. You can improve your home’s indoor air quality and help everyone in your family breathe more easily with frequent filter changes.

How Often You Use Your Heating and Cooling System

People who live in a temperate climate might enjoy a comfortable indoor air temperature year-round, and only need to use their HVAC system periodically. In that case, you could get by with changing your filter every six months to a year. The same is true for vacation homes that only see part-time occupancy.

The Size of Your House

If you live in a home with less square footage, you may need fewer filter changes. Why? It doesn’t take as much energy or on/off cycling for an HVAC system to get a small space to the desired temperature. Keep in mind, however, that smaller HVAC systems have correspondingly smaller filters, which may require more frequent changes.

The Air Quality in Your Home

Unsurprisingly, indoor and outdoor air quality also play a significant role in the average air filter’s lifespan. Indoors, contaminants such as pet dander, smoke, mold and chemicals from furniture and cleaning products can worsen health problems for anyone living with respiratory issues. Likewise, the pollen, vehicle emissions and smog found in outdoor air can cause health problems for many people. 

Why You Should Change Your Air Filter

Air filters are a simple, but crucial, component of your home’s heating and cooling system. Still, many homeowners neglect to regularly replace their air filter, or only do so haphazardly. Here are three crucial reasons to stick to a regular replacement schedule for your household air filter. 

Save Money on Repair Costs

From changing burned-out lightbulbs to fixing a leaky faucet, responsible homeownership involves hundreds of little tasks that prevent your house from falling into disrepair. It can be tempting to put these chores off as long as possible, but failing to replace your HVAC air filters can lead to an emergency breakdown that results in a surprise repair bill. Don’t learn this costly lesson the hard way when there’s such a quick, practical solution available. Why procrastinate on a task that takes less than 10 minutes and can keep every member of your household healthier and happier?

Save Money on Your Energy Bills

Air flows more efficiently through a clean air filter. A filter that has become clogged with dust, allergens and debris can’t function at peak capacity, which, in turn, forces your HVAC system to work harder to keep up with your home comfort needs. Dirty air filters require much more energy usage than clean ones do, which also means that failing to replace your air filter on a regular schedule translates into your home releasing more carbon monoxide and other toxic gases into the air. If you’re trying to decrease the size of your home’s carbon footprint and be more environmentally responsible, don’t overlook the need to swap your clogged air filter for a new one. 

Improve Your Indoor Air Quality

Your air filter is only one component of your HVAC system, but it performs the crucial role of keeping dust, pollen and allergens out of your home. Once this filter gets clogged, there is nothing preventing this debris from entering the unit and circulating through all your air vents, causing coughing, runny noses, watery eyes, sneezing, sore throats and other unpleasant allergy symptoms. The EPA estimates air quality inside homes and other buildings can be more polluted than the air outside – even in large cities. And, because most of us spend up to 90% of our time indoors, we could be placing ourselves at even greater risk. If your goal is to improve indoor air quality, look for HEPA filters.

How to Change Your Air Filter

Some people find the idea of do-it-yourself home maintenance like A/C repair intimidating. But If you’ve never changed your air filter before, the good news is that it only takes a few minutes, and you don’t need any specialized tools or supplies to do so. Follow these simple steps to change your air filter without breaking a sweat.

Turn Off Your HVAC System

There are two common-sense reasons to take this step. The first is your safety, and the second is to protect your HVAC equipment. If the unit is still running while you’re working on swapping the filter, dust and debris can get sucked into it. Be sure to turn off the unit at the thermostat, and shut off power at the circuit breaker as well.

Locate Your Air Filter

The next step is to find your air filter. There are several places it could be, depending on the make and model of your unit. Often, the filter is behind a panel in the wall or ceiling. In some systems, you’ll find the filter in the return air duct. If your heating and A/C systems use the same ducts, the shared air filter for both systems might be in or near the furnace’s blower system. Check your user’s manual for more information, or ask your HVAC service tech to show you where your filter is.

Determine the Size of Your Home Air Filter

If you browse the aisles of your local hardware store, you’ll notice several standard dimensions for air filters. It’s essential to ensure you’re using the correctly sized filter to fit your ductwork. Usually, this step is a cinch because most air filter manufacturers print the dimensions of the filter on its cardboard frame. That means you can identify the correct size with a quick glance at your old air filter. However, if you don’t see the measurements displayed on the old filter, you can use a tape measure to determine the width and length.

Remove the Existing Air Filter

Depending on the location of your air filter, removing it may be as simple as sliding it out of the slot that holds it in place. With other configurations, you might have to open the panel that houses the filter. This step could require a screwdriver to access the old filter, though in many cases, you can loosen the fasteners manually. Once you’ve taken out the A/C filter, evaluate it by holding it up to the light. A clogged filter will not allow much, if any, light to shine through. Put the dirty filter into a trash bag to avoid dispersing dust or other loose contaminants around your home.

Insert the New Air Filter

The design of HVAC filters only allows for a one-way flow of air. Before you install your new filter, look for an arrow on its frame indicating the direction of the airflow, which is always away from the return air duct and toward the air handler. When you put the filter back in place, make sure the arrow is pointing the correct direction. You might find it helpful to mark the airflow direction on your unit for future reference by drawing yourself an arrow with permanent marker.

Switch the Unit Back On

Now, the only thing left to do is to turn everything back on and enjoy cleaner indoor air. Switch on the power at the circuit breaker, then turn your thermostat back to the “on” position. Now that you know how to check and change your HVAC air filter and how often to do so, put an alert on your phone or calendar to remind you to do it at the appropriate intervals.

Reliable HVAC Repair in Delaware

If you didn’t know how often to change your filters and weren’t familiar with the basic process, it’s likely you’ve been overlooking other HVAC maintenance, too. Preventive maintenance agreements save you money and time by keeping your heating and cooling equipment in top working condition all year long. Contact your local HVAC repair experts at Above & Beyond Services for a thorough inspection and tune-up of your system so it won’t let you down during the heat of a Delaware summer, the chill of an East Coast winter or anytime in between. We welcome your call or email 24/7.