What is a HEPA filter?

This is an often asked question and important to understand.  Firstly let’s explain what HEPA stands for.


A HEPA filter has a required minimum efficiency of being able to capture 99.97% of all particulate pollution (dust, pollen, mould, bacteria, viruses) above 0.3 microns (µm). 

To put that into context the standard filtration in many HVAC/air con systems would be just 50% effective on particles sized between 3 and 10 microns.  In other words in laymens terms, a standard filter cannot trap airborne pathogens such as Covid, and is only 50% effective at stopping the larger particulate pollution such as dust.

A HEPA filter is typically a pleated mechanical air filter made from either plastic (PP+PET) or fibreglass.  They were developed in the mid 19th century in the United States, and first used by the US Army and National Defense Research Committee to protect thousands of workers from airborne radioactive pollution in the Manhatten Project (development of the Atomic bomb).

HEPA filters have been further refined and developed over the years to play a crucial part in preventing airborne infections and significantly improving indoor air quality in many different environments.

The use of HEPA filters in healthcare and medical facilities has long been proven to remove airborne contamination.  A recent study in the NHS on a COVID ICU ward showed that all airborne covid particles were removed from the air when HEPA filtration was used.  Additionally, mortality rate reduction has been confirmed after implementation of HEPA filtration in critical care environments.

There are 3 popular grades of HEPA filters, and the below table helps show how efficient each type is.


At Zonitise, we provide either HEPA 13 or HEPA 14 Filters with all of our air purifiers.

HEPA filters can be a standalone filter that is implemented into an existing HVAC system (subject to mechanical engineer agreement).  Alternatively and far more popular, HEPA filters are often used in stand alone air purification devices such as these.

It is often far more cost effective to install In room HEPA air purification than it is to upgrade an existing HVAC to the required filtration specifications for infection prevention and particulate matter removal.

Decided that you need a HEPA air purifier?

At Zonitise we distribute world class medical grade HEPA air purifiers for every type of space.  From a large corporate office to your kitchen!   You can check them out here!

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