How Often Should You Change Your Air Filter?

One of the most frequently-asked questions at CleanAir is, “How often should I change my air filter?”

The answer depends on your individual needs and how often your air-conditioning unit is used. This article will help you decide what timeline is best for your air filter subscription:

Different Factors Influence How Often You Should Change Air Filter

So, how often should you change your air filter? It depends on how often your home is occupied, if you have allergies or pre-existing medical conditions, and if you have pets.

The generic advice on most air filtration systems is to change the filter every 30 to 60 days. But, can you trust the manufacturer, or are they just trying to sell more filters?

Thirty to 60 days may be true for most households, but this is a basic timeline that might not be the right fit for your family.

For example, if you are the only person living in your home, and you don’t have pets, or you only use the home as a vacation home, then the AC unit should only need to be changed every six to 12 months, or longer.

If you live in the city and more than one person occupies your home, you will want to consider changing the AC unit every three months.

The need for filter changes goes up if you have more occupants in the home or if there are pets present. If you live in your home with one pet, you should typically change the filter every two months.

If you have more than one pet, if you are prone to allergies or have a medical condition such as asthma, you will want to change the filter anywhere from every two weeks to every month.

The rate at which you should change the air filter can also increase if you are doing any remodeling inside your home, or if there is construction near your home. Dust and other particles from construction can make their way into your air filtration system and easily clog the unit.

How Do I Know If my Air Filter Needs Changing?

There are ways to tell if your home has a dirty air filter. By keeping a close eye on these areas, you can tell whether your air filter needs to be changed ahead, or if you can hold off on a new one for another week.

There is no tell quite like looking at the filter itself, of course, but with the AC unit out of sight and out of mind, we rarely think to check the filter drawer. Following are a few signs that can tip you off to a dirty air filter that needs to be replaced:

  • Symptoms of Sickness or Allergies Appear

If you suddenly start feeling symptoms of sickness or allergies, your home’s air conditioning unit might not be filtering all of the pollutants out before recycling the air into your home. This may be a sign that you need to change the air filter.

  • Higher Electricity Bills

Higher electricity bills may be trying to tell you that your air conditioning unit is running longer than usual, which may mean it’s time for air filter replacement. Of course, many electricity companies change their rates seasonally, so it’s also important to keep an eye on your wattage charges to ensure that it is higher than normal electricity usage, rather than an upcharge.

  • Loss in Efficiency

When you first learn how often to change your air filter, it can be easy to miss some of the early signs. One of the most obvious signs the air filter needs to be changed is when the unit begins running longer but is not cooling or heating your home as efficiently. This loss in efficiency not only hurts the environment, but also causes significant wear and tear to your unit.

  • Visible Dust in the Home

If you begin seeing more visible dust particles in the air, it’s time to take a look at your home’s air filtration system. More dust is a clear sign that it’s not able to properly filter these particles from the air when it recycles air back into the home. This may be caused by a dirty air filter that needs to be changed, or an air filter with mesh that is too fine for your unit to process.

  • Visible Signs of Wear and Dust on Filter

One of the best ways to determine if you need to change your air filter is by periodically looking at the filter itself. If you can change your filter yourself, this is an easy task that won’t take you more than a minute or two to assess. A dirty filter will look worn and sag, with dust particles making the filter look visibly dirty. You may also notice dust coming off the filter as you pull it out of the unit’s drawer.

Does Changing an Air Filter Make a Difference?

The short answer is yes! Changing an air filter makes a difference, in more ways than one. The U.S. Environmental Protection Agency states that by regularly cleaning your air filters, you not only increase the efficiency of your air conditioning unit, but you also help keep your house cooler while lowering your electricity bill. (1)


By maintaining your cooling system regularly and cleaning those filters, you’ll increase the efficiency of your air conditioning and keep your house cool.” - Lina Younes,


Beyond the electricity bill, regularly replacing an air filter keeps your air fresher and healthier, reducing pollutants that cause allergies and other nasty respiratory conditions like asthma. Maintaining your air filter also helps reduce the wear and tear on an air system, helping you keep your AC unit in good working condition longer.

As if these reasons weren’t enough, regular air filter replacement also helps reduce the amount of carbon monoxide and other gasses that get released into the air outdoors since the system isn’t working nearly as hard to get through the clogged filter. This means you can help reduce your carbon footprint and make a real change in the environment around you.

What Happens if you Don’t Change Your Air Filter?

If you do not change your air filter, the unit itself will begin to fail.

As the dust clogs the filter, you will start to feel a loss in efficiency in the heating or cooling of your unit, and it will be unable to filter allergens and dust out of the air. Your indoor air quality will suffer greatly.

Over time, this dust clogs other moving parts inside your AC unit and can lead to an expensive fix, or worse, replacing the entire unit, which can easily range in the thousands of dollars.

If you use heating, you may begin to smell a burning smell as the dust burns off inside the unit, which is a fire hazard that can also add more wear to the unit over time. Air conditioning may not cool your home, leading to the unit freezing, which damages the internal workings.

Changing the air filter is an inexpensive way to ensure the health and safety of everyone in your home, as well as maintain a working AC unit for years to come.

How to Change Air Filters in Your House

While the CleanAir subscription service offers installation with your air filter delivery in case you can’t or don’t want to change your air filter, that doesn’t mean that it’s a task that can only be done by the professionals.


“Maintaining your air filter also helps reduce the wear and tear on an air system, helping you keep your AC unit in good working condition longer.”


There are typically instructions on how to change the air filter on the unit’s filter door, and in most AC units, you only need to open the filter door, slide out your old filter, slide the new one in, and close the door again. (2)

Of course, there is a catch – your air quality can also depend on the type of filter you’re using to replace the old one.


“The habit I have seen people get in to is they either get the really cheap one or the most expensive one. The cheap one is not stopping anything, it is barely stopping the dog hair from coming through if you have pets in the house. The expensive one does not allow the air flow to go through because your system is not made to handle that kind of filter.” - Derek Cole, Huffington Post


Near the installation instructions, your unit should also inform you what type of filter you need, including size, rating, and any other information specific to your unit.


  1. U.S. Environmental Protection Agency
  2. Huffington Post