What exactly is a HEPA filter?

What exactly is a HEPA filter?

A “HEPA” stands for high-efficiency particulate air filter, these filters are often used in hospitals and other industries where clean air is required.  For example the food and pharmaceutical industries and also microelectronics industry. That’s a special type of filter that captures microscopic particles such as pollen, dust, pet dander, bacteria, hair, mould spores and any particular matter that comes from the outdoor air pollution.


Do HEPA filters come in different types?

When you’re looking to purchase an air purifier equipped with a HEPA filter you may come across devices that have different types of HEPA filters, such as:

True HEPA – captures the widest range of contaminants, and are certified to capture 99.97% of particles as small as 0.3 microns.

HEPA, HEPA-like and HEPA-type – capture a smaller range of contaminants, and are certified to capture particles that are 2 microns or larger and they miss ultra-fine pollutants.

The differences between these are big as the True HEPA filter is almost 500% more efficient than the other types.


How do air purifiers with HEPA filters work?

Air purifiers with HEPA filters are devices that clean the air by removing microscopic contaminants. These filters were designed during the Second World War as part of the Manhattan project to control radioactive particles.  

The True HEPA filters are made from fibreglass arranged in a mat of randomly placed fibres.  Particles such as dust, pollen, pet dander and various allergens are trapped by sticking to the fibre through diffusion, interception or impact.

The very tiny particles are trapped through the process of diffusion, it’s the process that slows down the contaminants as they collide with gas molecules.  As a result, they stick to the fibres of the filter.

Small particles as they flow through the filter they are intercepted and stick.  Larger particles simply cannot get through fibres of the filter without hitting them directly.  As a result, they get captured inside the HEPA filter.


 What are the benefits of HEPA filters for allergy relief?

Air pollutants such as dust mites, mould spores, pollen, and pet dander can cause serious problems if a member of your family has allergies or asthma.  Using an air purifier with a True HEPA filter may help bring allergy relief by removing air born particles.


What are the advantages of HEPA filters?

These type of filters come in different sizes and budgets and they are very good at capturing both large and small particles from the outside air. They offer a great advantage to the individuals suffering from asthma, allergies or any other respiratory problems.


 What are the drawbacks of HEPA filters?

The only drawback to HEPA filters is that they can’t capture viruses, odours and chemical gases because these particles are too small and will require a different type of filter to trap them.

How often does the HEPA Filter be replaced in air purifiers?

The time when you need to replace your HEPA filter depends on two things.  If the air purifier has two methods of purification, HEPA filter and an active carbon filter then the HEPA filter needs to be replaced ones a year and the active carbon filter every 6 months.

Also, the frequency of filter replacement depends on the environment where your air purifier is placed and on the filter manufacturer.

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