What is a HEPA Filter and How Does It Work?

Air pollution is a major problem faced today. Whether air pollution is within your house or is an external environment, it causes major damage to our respiratory organs. Though air pollution in the environment cannot be controlled by us, we can obviously take measures to prevent air pollution within our house and prevent from being sick or allergenic.

The minute dust particles that come from the outside environment stay cannot be seen. Thus the dust particles which cause respiratory problems can be solved with the use of HEPA Filter aka HEPA air purifier.

HEPA filter system
What does a HEPA filter do?

What Exactly is A HEPA Filter?

HEPA stands for High-Efficiency Particulate Air. Thus it is a filter which is generally included as a part of air-purifying machines or vacuum cleaner to entrap minute dust elements or microorganism. HEPA air purifiers not only trap the dust particles but they also prevent them from spreading other bacteria and viruses which can damage our organs.

True HEPA air purifier is approximately 99.97% successful in trapping particles as small as 0.3 microns. Thus, it is the most efficient filter found these days in vacuum cleaners which let us breathe in fresh and pure air. It is also considered as the luxury home stuff.

HEPA air purifier was initially manufactured by the nuclear industry to capture hazardous radioactive particles. But now it is majorly used in all vacuum cleaners and air purifiers.

Reference: explainthatstuff.com

The Invention of HEPA Filter

The fiber-like filters were first used during the Manhattan Project to trap exceptionally hazardous minute radioactive particles. Slowly and gradually the HEPA air purifier developed basically for industrial use. Later on, they are now commonly used in residential apartments and commercial offices to clean large and small dust particles.

How Does HEPA Air Purifier Work?

The basic type of filter works as a strainer that has small holes to capture large particles like dust, dirt, and hairs, but the small particles cannot be captured with the help of basic filters.

Thus, the HEPA air purifier was introduced mainly to trap the smaller particles from the air. The HEPA filter in the vacuum cleaners makes use of two diverse types of machinery.

First, the outer layer works as a basic filter that acts as a strainer to prevent the big dust particles. Secondly, the inner layers which materialize similar to a folded material with opaque glass fiber mat finish.

This layer does not work like a strainer; instead, it traps the particles in different techniques. The heavy particles which move slowly and gradually stick to the fiberglass (Diffusion). Lightweight particles travel faster either have a collision straight with fibers (impact) or get fascinated by them while passing (Interception).

how does a hepa filter works
HEPA filter diagram

This diagram shows the three methods the HEPA filters use to catch dirt and dust.

Image source: spotlessvacuum.co.uk

Types of HEPA Filter

An ideal HEPA filter for the best air purifier is the one that captures 99.97% of minute dust particles as minute as 0.3 microns. Only a real HEPA Filter can achieve the above-mentioned objective. Thus, this way you can adjudicate whether your filter is a True HEPA Filter or not.

HEPA Filter is classified with A to E stickers depending on their efficiency. Type A is considered to be the least efficient and Type E the most efficient appropriate for defense-grade applications. Vacuum Cleaners generally have Type A filters which work efficiently within our house.

How Often Does the HEPA Filter be Replaced in Air Purifiers?

Replacing your HEPA Filter in air purifiers is dependent on two things. First, if your purifiers include a HEPA filter and a carbon filter then the carbon filter needs to be replaced within 6 months and HEPA Filter once in 24 months.

These replacements also depend on factors like the filter manufacturer, a total surface area of HEPA Filter and the environment in which the HEPA Filter functions. At last, low-quality air purifiers need to replaced annually and the best quality ones are suggested after 2-3 years’ time interval.

Advantages of HEPA Filter

  • It captures both large and small particles in the air, thus, giving fresh and clean air.
  • Highly recommended for individuals suffering from asthma and allergies.
  • They are available in different sizes and budget to match your requirements
  • It has a higher level of work efficiency. It captures around 99.97% of minute dust.

Disadvantages of HEPA Filter

  • HEPA Filters cannot be cleaned or washed to remove the dust particles. They can just be replaced which can be quite an expensive task.
  • HEPA Filters are tremendously delicate and hence could damage easily while cleaning, installing or moving the purifier to do the cleaning. Hence it needs utmost care while using.
  • Replacing HEPA filters which are of branded quality will shell out your huge money.
  • Some HEPA Filters can even produce ozone or ions which could be harmful

Things to be Considered Before Buying

  • Cross-check that you are buying a genuine HEPA Filter by checking the guarantee and warranty offered by manufacturers.
  • Always buy the product from a reliable source
  • HEPA Filters require regular cleaning and replacement. Thus, calculate the replacement cost in advance to have knowledge about its future expenses.

The need for HEPA Filter

The HEPA Filters are worth buying these days as the air pollution levels have increased by an enormous percentage. Though the filters are expensive, they offer a great advantage to the individuals suffering from asthma, allergies or any other respiratory problem. The HEPA Filters work efficiently to provide you dust-free clean air to breathe in. Thus, they provide value for our money.

Reference: https://en.wikipedia.org/wiki/HEPA


There are many different kinds of air purifiers available in the market with different technologies. Some may have HEPA, carbon, ionizing, UV technology and many more. Some purifiers also contain more than one technology for advanced functioning and better results. Thus, choose the best one matching your requirements and budget.

The main function of the HEPA Filter is to remove contaminated viruses from the air and provide clean and pure air. Thus, HEPA Filter is a crucial purchase element for the one suffering from dust or pollen allergy. Strict standards have been set for the filters to be classified as HEPA. A HEPA Filter should be able to remove 99.97% particles being as small as 0.3 microns.

So buy only a quality product from reliable sources and avoid buying β€œHEPA-Type” or β€œHEPA-Like” filters, as these filters will not provide you the best result as compared to the true HEPA Filters.

At last, there are many sources from which you can order your HEPA Filter Air Purifier. Why wait for more to avail such luxury home stuff. Click here if you like to buy the best HEPA Air Purifier.

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