What is a HEPA filter and what function does it serve in air purifiers? If you start doing some research online regarding air quality, you will quickly come across this term and you will start seeing it being mentioned everywhere. So what exactly are "HEPA" filters, and what makes them so special? Let us find out and see if all HEPA filters are made equal.
What is a HEPA air filter?
HEPA filters are a type of air filter that meets European standards. Air filters prevent certain molecules or particles from remaining in the air we breathe. Filters are used in cars, heaters, vacuum cleaners, CMVs and more. In these examples, filters act as a barrier against dust and other foreign bodies which could come impair the operation of the machine’s engine. When dust accumulates can, it can negatively affect the operation of a mechanism, reduce its power output and even seriously damage it over time.
In air purifiers, HEPA filters play a similar same role except instead of protecting an engine, they protect our health. They are used in combination with many other technologies and types of filter in different layers more a more thorough filtration of organic and harmful particles. The main role of a filter is to trap all harmful particles in the air we breathe, before it goes through our lungs. In the absence of filter, it is the alveoli of our lungs that have to deal with fine particles and other microscopic pollutants. They often end up accumulating in our lungs, at the expense of our respiratory health.
What do HEPA filters offer compared to non-HEPA filters?
As mentioned, HEPA filters are a type of air filter where the acronym HEPA stand for "High Efficiency Particulate Air".
HEPA filters are defined by the EN 1822 standard, which came into effect on January 1, 2009. This is currently the highest and strictest standard in the world. It applies to all devices capable of filtering at least 85% of the particles with a diameter greater than or equal to 0.3 μm. It also states that filtration should be done in a single pass.
As stated by the Ministry of Health: "Chronic exposure to air pollution is what leads to the most important effects and therefore impacts on health". When this pollution enters our homes and our indoor air, it has a much greater negative impact on our health. That is because we then go from a temporary exposure to a clear overexposure, with all the associated damages to our respiratory system and our health. This is why the European standard was set very high.
What is the role of HEPA filters in air purifiers?
Air purifiers equipped with HEPA filters bring a very important level of filtration to your indoor air, capturing almost all the particles it contains. These particles come in various forms: cigarette smoke, kitchen odours, harmful gases, volatile organic compounds (VOCs), pollutants emitted by candles or other air fresheners. HEPA filters are mainly composed of activated charcoal and various interwoven natural fibers.
Thanks to the stacking of several layers, HEPA filters is able trap all particles while only using natural processes. Particles greater than 1 micron are physically stopped by conventional filtration, while particles smaller than 100 nm are attracted and intercepted by dedicated layers (bamboo fiber). The smallest particles, less than 0.3 μm, are stopped and destroyed by other natural chemical processes (activated charcoal).