How Often Should I Change My Air Purifier Filter?

Air purifiers can be beneficial for those who suffer from asthma, allergies, and chemical sensitivities. They can improve the quality of air inside your home by trapping dirt, neutralizing foul odors, neutralizing smoke and chemical fumes, and eliminating germs.

However, to keep up such quality, air purifiers need regular maintenance and will periodically require filter replacements. Most air purifiers require filter changes to be made every now and then, and the replacement schedule generally varies according to the type of filter. Knowing the degree of upkeep required by different air purifier types will help you make an informed purchase as will this article, which highlights how the filters function in air purifiers to reinforce why replacement is so essential.

Why should you replace air purifier filters regularly?

When an air purifier is running inside your home, your family enjoys clean and refreshing air that’s relatively free of irritants. This is because those irritants have been trapped in the filter. As air passes through these filters, dust, pet dander, and other allergens and particles get entangled and accumulate over time until the filter gets saturated. This explanation also applies to adsorptive filters like carbon, which consume odor molecules and chemical fumes in the air.

A filter that’s ridden with collected pollutants, however, gradually loses effectiveness. Aside from running out of space for newly-trapped particles, air can’t pass as efficiently through saturated filters. As a result, regularly putting a fresh new filter in place can keep your air purifier running at its optimal state.

Do all filters need to be replaced?

Some manufacturers have recognized the need for models that require lower long-term costs, which led to the development of air purifiers with washable or permanent filters. These models eliminate or significantly lessen the need to regularly purchase replacement filters. These filters still need to be cleaned, though, so to maintain effectiveness they have to be washed or vacuumed consistently.

In short, regardless of whether you have disposable, washable, or permanent types in your air purifier, all filters come with a lifespan. They have to be replaced or cleaned regularly as a part of your air purifier’s maintenance requirements.

So what frequency is best?

The ideal frequency by which you should replace your air filters depends on a number of factors. Let’s look at some of these elements in closer detail:

  • Default indoor air quality: The dirtier the air normally is in your home, the faster your filters will reach their maximum capacity. Expect shorter filter lifespan, for example, if your house is situated along a busy road (full of cars that emit pollutants and smoke) or if there are smokers and pets in your household.
  • Frequency of usage: Obviously, an air purifier that runs 24/7 will need more maintenance than another unit that only runs during certain times of the day or at certain days of the week.
  • Water quality: The lifespan of washable filters is affected by the quality of water in your household. Tap water that’s rich in mineral deposits can compromise the longevity of your filter, since these mineral deposits can potentially cause unwanted clogging.
  • Filter type. Some filter types need to be replaced more frequently than others. For instance, pre-filters typically need to be cleaned on a monthly basis, while HEPA filters have a longer lifespan. Check out our ultimate guide below for more.

Knowing the best time to change filters can be confusing. This is why some air purifiers come with filter check indicators out of the box. This feature lets the user know either through an LED indicator or beeping signals that the filter inside has to be replaced or cleaned. Not all models, though, come with such a feature.

General Filter Replacement Schedule

Our ultimate guide below lists the typical replacement schedule for different filter types and should give you an idea of how frequently different filters have to be replaced. If the information is not made available to you by the specific manufacturer, go ahead and check what type of filter is used in your air purifier and check its lifespan below:

  • HEPA Filters: Must be replaced every 12 to 18 months
  • Carbon Filters: Must be replaced from three to six months
  • Pre-Filters: Must be cleaned every 30 days and replaced when worn out
  • Permanent Filters: Must be cleaned every three months and replaced when damaged

Keep in mind that this is a general guide. There may be certain setups that are exemptions to the rule, especially considering the fast-paced growth and development of the air purifier industry where new technologies and filter types are continuously being developed. Nevertheless, the figures above hold true for most air purifiers. If a specific air purifier goes off the beaten tracks and demands a special schedule, the brand will most likely specify it on the product manual or website.

Frequently Asked Questions

Are there signs that my filter needs changing?

If your air purifier doesn’t come with a filter change indicator, you can also determine if a filter change is needed through the following telltale signs:

  • The filter exhibits noticeable dust and dirt buildup, giving it a distinct gray color
  • Your home is dustier than usual
  • There’s an obvious increase in the amount of pet dander circulating in the air
  • You or your loved ones are experiencing more frequent or more severe asthma and allergy symptoms
  • You’re starting to notice poor odor and smoke control

Remember: your intuition helps! No matter what the prescribed schedule is for the particular filter you’re using, it’s best to replace or clean it as soon as you notice significant dirt and deposit buildup that considerably hampers performance.

Do I need to dry my washable filter after cleaning?

Yes! It’s important to thoroughly dry washable filters before putting them back inside your unit. Failure to do so can lead to mold formation and growth, which will make your air purifier emit foul odors.

What else can I do to ensure the longevity of my air purifier and its filters?

You can significantly extend the lifespan of your filter by minimizing inside smoking and/or closing off your house from entering dust, smoke, and dirt.

You can also ensure that your purifier continues to function well by keeping up a regular filter check and replacement schedule. Neglecting your air purifier’s filter replacement schedule can result to harmful pollutants and bacteria getting recirculated around the room.

Further Reading