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How Often Should AC Filters Be Changed?

When is the last time you changed your AC filter? Changing the AC filter in your home is not always top of mind, and understandably so. Life gets busy and it’s a task that can be easily overlooked or forgotten. But the importance of changing your AC filter cannot be overstated. A clean AC filter helps to deliver clean air into your home, and that’s important for the health of the occupants. But knowing when to change the filter varies, depending on general usage, number of pets, household size and quality of the air filter being used.

Basic 1-inch to 3-inch air filters should probably be replaced every 30 to 60 days. If people in the home suffer from allergies, you could purchase a higher quality air filter and replace it more often. As a general rule of thumb, however, service experts recommend the following:

  • Vacation house or single occupant without pets or allergies: every 6 to 12 months
  • Common suburban house without pets: every 90 days
  • Household with one dog or cat: every 60 days
  • Household with more than one pet or an occupant with allergies: 20 to 45 days

What AC Filter Should I Buy?

Like with so many products today, the selection can be daunting. The same is true of air filters. Let’s take a closer look to gain a better understanding of the different type of AC filters and the benefits of each.

  • Pleated air filters: These are easy to recognize because you can actually see the pleats, or folds, in the fabric. They are particularly effective at filtering dust and other pollutants. As a general rule, the more pleats there are, the better the filtering performance.
  • HEPA air filters: If you or someone is an allergy sufferer or struggles with respiratory difficulties of any kind, HEPA filters should be your number-one choice. These high-efficiency particulate air filters (HEPA) can effectively screen up to 99.97% of the contaminants in the home. It’s no wonder the Department of Energy recommends this type of AC filter over the others.
  • UV air filters: These filters use ultraviolet light to kill bacteria and viruses in the home, which are also dangerous to the health of the occupants. The tradeoff is that there are less efficient when it comes to screening dust and other pollutants.
  • Washable air filters: You will pay a higher upfront cost for these filters, but there’s a payoff in the long run. As the name implies, they can be removed and cleaned, so you don’t have to replace them as often. One word of caution, however, is to make sure the filter has dried before replacing it in the unit. A damp filter can lead to mold growth and bacteria buildup.
  • Fiberglass air filters: These filters come with the convenience of being disposable and affordable, but it’s clearly a case of you get what you pay for. While they do a good job of protecting the air conditioner, they may fall short when screening dust and pollutants out of the air.
  • Electrostatic air filters: Available in both washable and non-washable forms, an electrostatic air filter uses electrostatic charge to collect dust and airborne particles from the air, which in turn prevents them from moving around in your home.

How Often To Replace An AC Filter

As already mentioned, there are some general rules to follow about knowing how often to replace your AC filter. Much of it has to do with the conditions in your home, including who lives there and the health of those occupants. Chances are, you need to be changing your AC filter more often than you think. Let’s look at some common scenarios and how they affect the replacement time of your air filters.

  • Do you have pets? Both dogs and cats shed, and that hair builds up over time, especially during a change of season. For this reason, you will need to change your AC filter every two months.
  • Do you have younger children? Air quality needs to be at its best when little ones are living in the home. It’s best to change the AC filter every two to three months to help ensure that your home is clean and the air quality is being properly managed.
  • How often do you use your air conditioning? In less harsh climates, you may not need to use your AC very often. The same is true of your heat. If that’s the case, you may only need to change the AC filter once or twice a year. On the other hand, constantly running your AC system dictates more frequent replacements, perhaps every six weeks. Moderate usage falls somewhere in the middle, with recommended replacement of every two months.
  • What’s the size of your house? Generally speaking, air conditioners and furnaces in smaller homes don’t need to work quite as hard. They pump out less air for the same amount of temperature change. And that translates to fewer filter changes. Likewise, a larger house would require more AC filter changes. Keep in mind, however, that smaller houses could use smaller appliances to cool the space. If the filter is smaller, it will need to be replaced more frequently.
  • Do you or members of your family suffer from allergies? The Allergy and Asthma Foundation of America (AAFA) states that indoor air quality is just as important as outdoor air quality. Outdoor air may contain harmful pollution, but indoor air quality can be affected by indoor pollutants such as allergens, dust mites, pets, cockroaches and mold. Scents, chemicals and items that release gasses called VOCs are more prominent inside the home. VOCs typically originate in new furniture, carpeting, building materials, cleaning supplies, and more.

How to extend the lifetime of an AC filter

Needless to say, you may want to limit the number of air filter replacements based on convenience and monetary reasons. In an effort to extend the life of an AC filter, start by cleaning the outdoor AC unit on a regular basis. Remove any plants, dirt or debris and then wash it with an ordinary garden hose. It’s also important to schedule regular HVAC maintenance checks and to have your home’s air ducts cleaned every year. These three but simple steps go a long way toward keeping your unit running efficiently for a longer period of time. But they also help to improve the quality of air and the health of the occupants.

When to call a professional

If you continue to have problems with an AC filter after trying to fix it yourself, it may be symptomatic of a more serious issue, and you may want to consider a professional option. Anew offers an easy, efficient and affordable repair service with remote diagnosis.

Get answers with Anew

Video chat with an expert to pinpoint your home’s issues remotely, then get it repaired fast with Anew’s DIY or Professional solutions.

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Get answers with Anew

Video chat with an expert to pinpoint your home’s issues remotely, then get it repaired fast with Anew’s DIY or Professional solutions.

Get Started

The information included on this website is for informational purposes only, is general in nature, and may not be applicable to your specific situation. We do not make any warranties about this information, and it is not a substitute for professional advice. Any home repair decisions or actions made about your property are your own, and are strictly at your own risk, and we will not be liable for any losses and damages in the connection with the use of our website or your repair decisions. It is your responsibility to understand and comply with any applicable local, state, or federal codes, laws, rules and regulations. You are assuming all risks related to home repair and maintenance. See the site’s Terms & Conditions for additional important information.