Air Purifier Filters and What They Do

If you've been shopping for an air purifier, then you've definitely come across terms like "HEPA Filters" and "Carbon Filters" and scratched your head wondering what these meant and how these make an air purifier better. Or maybe you've wondered, how does this unit remove odours, or how can this model kill germs? 

The answer is in the type of air filters the unit uses. We explain what each air purifier filter does and how they work, so that when you shop for an air purifier, you'll know how it works and what it can do for you. 


HEPA Filters

HEPA stands for high efficiency particulate air, and this type of filter is widely considered to be a standard amenity in home air purifiers. It is effective at removing the majority of finer particles commonly found in the air at home. This includes pet dander, pollen particles, and mite residue. Both homes and apartments (especially in urban areas) are prone to an inevitable accumulation of dust residue. The HEPA filter is especially effective when used to compliment a traditional air filter. Since older air filters are most effective at removing larger particles and irritants, the performance of the HEPA filter is optimal. As such, it will last longer and be less likely to break down in the long run. The gold standard in residential filtration systems; HEPA filters are proven to remove over 99.97% of particles larger than 0.3 microns.


Carbon Filters

Carbon filtration was a breakthrough in the advent of clean drinking water. A hundred years later, it’s still proving to be a useful component of new technological breakthroughs. Carbon filters are some of the most effective odour filtration devices on the market. The carbon in carbon filters react with oxygen in the air, and this chemical reaction changes the chemical makeup of the carbon by stretching out the molecules. This change exponentially increases the absorbency of the filter, essentially creating a surface area averaging 100 acres!  The oxygenated carbon filter is a foolproof way to trap odours and gaseous pollutants, which pass right through HEPA and other conventional filters.



Pre-filters are an economical means of saving time and money replacing a household’s air filters. They are the first filter that air must go through in an air purifier, and they increase the efficiency of the other air filters in the unit by preventing the largest particles from ever reaching the main filters. This ensures that the  air filtration system is in optimal condition.


Ioniser Purifiers / Negative Ionisers

Like a lot of industrial equipment, people are starting to discover the effectiveness of ionising air purifiers. Developers are integrating ionisers into residential projects. They work by using a heated metal plate to convert air particles into their ionic state. These ions attach to air pollutants and are magnetically attracted to the plate surface. This is one of the most advanced yet effective air purification systems on the market.

Read more on negative ions


Titanium Dioxide (TiO2)

Most air purification systems use absorption technology to cleanse the air of various residual particles and pollutants. Titanium dioxide filters use a radically different technology; converting the chemicals themselves. When combined with calcium carbonate, Titanium dixoxide will neutralise any gaseous molecules; this is environmentally friendly decomposition process known as Photocatalysis. 


Ultraviolet (UV) Germicidal Radiation

UVGI systems implement fans UV lamps to sterilize the air in indoor environments. The fan forces air past the UV light at such a speed that it breaks down any organic particles or organisms (dead or alive) This is a very effective system to prevent the growth of mold or other biohazardous cultures. It is imperative that the device is placed in close proximity to a filter. This way, the filter is able to absorb the airborne components broken down by the UV lamp. 


TiO2 + UV light rays

When UV light is combined with a TiO2 coated filter, photocatalysis occurs. This is a process that creates hydroxyl radicals and super-oxide ions, which are highly reactive electrons. These highly reactive electrons aggressively combine with other elements in the air, such as bacteria and VOCs. Once bound together, the chemical reaction oxidises the pollutants, which breaks the pollutants into harmless carbon dioxide and water molecules.