HEPA Air Purifier Filters Explained
Before buying an air purifier, it’s important to understand the different filtration stages available so that you can make an informed decision. Generally when we talk about an air purifier, we refer to a HEPA air purifier. This is an air purifier with a HEPA filter which is one of 4 main different types of filtration found on a modern air purifier.
I’ll go into these in more detail below, but for now I would like to put it out there that the HEPA filtration stage is extremely important. You should really only be looking at air purifiers which include a HEPA filter. This is the filter that has been approved to remove 99.97% of particle matter measuring 0.3 microns in size. It is these fine particles that have been proven to negatively affect our health and so removing these are our priority.
That said, keep reading below for an overview of the 4 main different types of filtration stages you will find on a hepa air purifier.
1. Preliminary Filter
A hepa air purifier may come with a preliminary filter. This would be the very first stage of filtration which removes larger particles measuring around 20 microns and above. For example dust particles, pet hairs and pollen would start to be eliminated at this stage.
This is a very useful stage of filtration as it extends the life of the following, more sensitive filters. Generally a hepa air purifier fitted with a preliminary filter will last longer than a hepa air purifier that is not fitted with a preliminary filter.
2. Carbon Activated Filter
A carbon filter, or carbon activated filter is made up of specially treated carbon that has very fine pores through which air can pass through. As air passes through the carbon, particles responsible for unwanted odours are trapped and therefore removed from circulation. A carbon filer is crucial to remove odours from cooking, pets and smoking.
3. Cold Catalyst Filter
If you find a hepa air purifier fitted with a cold catalyst filter (such as the VonHaus air purifier) then this has the added benefit of decomposing harmful gases such as ammonia which is found in cats urine and methanol which can be found in solvents and fuel. A cold catalyst filter also has an anti-bacterial effect, making the air safer to breathe.
4. HEPA Filter
A HEPA filter is one that has been tested and approved to remove 99.97% of particles that measure 0.3 microns or larger from the air. Fine particle matter has been proven to cause and exacerbate various health problems. Respiratory health problems, asthma and hay fever are just a few issues linked to fine particle matter.
A HEPA filter uses a specially woven materially that traps these tiny particles and removes them from circulation in the air in our homes. This is arguable the most important filtration stage of any air purifier and should be top priority.