how often to change hepa filter in air purifier ?

Air purifiers have become a must-have component in a modern home. It is mainly due to the increasing amount of pollution and other harmful particles in the air. Moreover, certain bacteria and viruses are also found in the air, and the best remedy is to use an air purifier. However, the most repeated question is how often to change a HEPA filter in an air purifier?

Hepa filter

What is a HEPA filter?

Before we get started on how often you should change a filter. It is best to know about the function of an air filter and its different types. An air filter is the most significant component of an air-purifier. For instance, all of the harmful particles in the air are removed due to these filters. An air filter is a mesh-like structure with micro-level holes.

The word HEPA stands for “high-efficiency particulate air [filter].” It is a mechanical type of filter made up of glass fibers. The mesh diameter is so small that particles larger than 0.3 microns get filtered out very easily. HEPA filters are one of the most efficient air filters globally, with an efficiency of 99.97%. Therefore, along with everyday household dust, HEPA filters trap smoke, dust mites, molds, bacteria, pollen & even air-born virus. The total service life of an average HEPA filter is 8760 working hours.

How often to change the filter?

Different manufacturers of the HEPA filter provide different service life specifications. According to most advertisements, a HEPA filter can last up to 5 years before it starts loosing quality. However,  the service life depends on many aspects such as environmental conditions, working hours, pollution, dust levels in the area, and the type of area in which the filter is being used.


Daily Usage Service life
2 hours 6-8 years
5 hours 4-5 years
8 hours 1-2 years
12 hours 6-12 months

Why do you need to change the air filters?

Air filters are mesh-like structures with extremely tiny holes in them. You can appreciate the natural air in your home or office, liberated from dreadful pollutants and odorous by using an air purifier. The air goes through the channels and gets caught.

These particles are of various shapes and sizes, such as dust and different allergens. The contaminations are collected noticeably all-around mesh. Likewise, numerous carbon air channels are absorbent, which means they soak smell and pollutants from the environment.

Since numerous channels gather contaminations, the serviceability of the air filter decreases over time. Moreover, if the filter is not changed regularly, the mesh holes become clogged and fail to filter the air. It can result in several dangerous scenarios.

For instance, when the mesh is clogged, the air-purifier still tries to filter air and gets overheated. Secondly, some of the residue present on the mesh surface can fly with the pressurized air and spread diseases. These are the reasons why routinely changing your air channel is so important. Furthermore, It will also keep your air purifier running at the best quality and increase your air purifier’s life.

Types of HEPA filters:

There are two different types of HEPA filters. However, both types are based on the same principle of filtration. The main difference is their service life and price. These types are:

  • Washable HEPA filters
  • Permeant HEPA filters.


 Washable HEPA Filters:

People often confuse the washable HEPA filters with permeant HEPA filters. Both these filters vary a lot in terms of their service life and pricing. Moreover, the material for permeant HEPA filters is not suitable for washing and may damage if washed.

Washable HEPA filters last longer than ordinary air filters and have an average life of 8760 working hours. However, like other filters, the HEPA filter mesh also gets clogged within 1-2 months.

However, unlike ordinary filters, you don’t need to change the filter just yet. You can easily wash the washable HEPA filter and use it again until its service life is over. Hence, if you use your air-purifier for 5 hours daily, it would be best to change your washable HEPA filter every 1-2 years.


Permanent HEPA Filters:

Permeant HEPA filters are expensive than washable filters but remain economic in the long run. The permanent HEPA filters can last for many years without requiring any replacing. The most interesting thing about these filters is that you can reuse them repeatedly until they are damaged. Otherwise, the filter may pass on from generation to generation if properly maintained.

The maintenance procedure for the permanent HEPA filters is very straightforward. Unlike the washable HEPA filters, you don’t need to wash them every month. Instead, if the filter gets clogged, you can vacuum clean the filter and put it back inside the air-purifier. For an average use of 5 hours, it is recommended to vacuum clean a permanent HEPA filter every 2-3 months.


Difference between pre-filters and permanent HEPA filters:

Most of the air-purifiers come with built-in mesh pre-filters. You can use them over and over without typically having to buy replacements. However, it would be best to clean these filters every two weeks; otherwise, they start malfunctioning. Moreover, these filters get damaged after a certain period of time, and the replacement is costly. The mesh pre-filters are based on old technology and are not as effective as a HEPA filter.

On the other hand, the permanent HEPA filters are far more durable and practical than the mesh pre-filters. They can purify up to 99.97% of the air and block any contaminations larger than 0.3 microns. The washing of permanent HEPA filters is also effortless and needs to be vacuum cleaned after 2-3 months. 

What is an air purifier and how to choose one” if you have this question in mind do check out this article.


80% of diseases and allergies are caused due to polluted air. The best way to prevent such hazards is to install an air purifier in your house. The HEPA filters are the latest technology air filters that last longer than any other and require minimum maintenance. So, install a HEPA filter, sit back and enjoy the clean, fresh air.


I'm Julia, an air purification expert and certified Indoor Air Quality Professional. With a Master's in Environmental Science and a decade of research at the National Institute for Environmental Health Sciences, I've dedicated myself to understanding air pollutants and their health impacts. At 'PureAirly', my mission is to leverage my expertise in air purifiers and guide you towards cleaner, healthier air.

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