Air purifiers come with filters and they are the muscle behind it all. This is why they are amongst the most important features to check up on an air purifier. They do the heavy lifting of cleaning the air using different mechanisms. Which is the reason why you need to know the difference between your air purifiers.

In this article, we take a look at the difference between a Hepa and a true HEPA filter. What does it all mean and why should you choose one over the other? we look at what one offers that the other doesn’t and also what could be better. let us take a look.


Hepa is an acronym, for high-efficiency particulate absorbing/air/arresting. It is one of the best ways of reducing indoor pollution. It is a pleated mechanical filter used to clean the air of different everyday contaminants. There is more of it in our spaces than we realize. Hepa, is an acronym, meaning high-efficiency particulate air. It will clean the air of 99% of air contaminants. 

However, it will only get rid of particles larger than 2 microns in size. This means it can clean the air of pet dander and dust. A HEPA filter needs to satisfy certain levels of efficiency for it to be termed a HEPA filter. This way, the customer knows what they are getting when they buy a unit with a HEPA filter. 

Some of the things that affect the way a HEPA filter works include the way that it is made. The particles are stuck to fibers as they are passed through the filter, using diffusion, interception, and impaction. 


A true HEPA filter is a filter that removes 99.97% of air contaminants. It is more effective in removing the smaller members of the air contaminant family. It is often found in the more premium air purifiers that will also cost you more than the average system. True HEPA filters are made of highly dense materials, usually fiberglass.

The construction of the filter allows it to capture microscopic particles such as the sizes that can make it into your lungs and cause reactions that can turn out to be fatal. True HEPA filters use inertial interception, impaction, as well as diffusion mechanisms, just like HEPA filters.

Favourite Features


A HEPA filter is a must-have in an air purifier, especially if you want to get rid of pollutants that are potential causes of allergies. A HEPA filter has the ability to trap most of these, and the good thing is that you can get it in an everyday air purifier at an affordable price. You can also find them in vacuum cleaners in addition to air purifiers. They can either be made of either plastic or fibreglass.



The true HEPA filter has a lot of similar features with a HEPA filter such as using the same mechanisms to purify the air. This filter features the ability to clean the air of microscopic organisms that would otherwise be impossible to deal with using another type of filter.


Filter density

These two filters are both very efficient however they have different filter density. A true HEPA filter has high density whilst a HEPA filter has medium filter density. 


Both filters are quite efficient, in their own right. However, they can only clean the air of certain particle sizes. The true HEPA filter can clean the air of 99.97% of particles that are in the air and those that are 0.3microns in size. This means that a true HEPA filter will clean the air of particles as small as viruses and bacteria and mold. The dangerous bits that can make their way into your lungs and cause notable harm.

Hepa filters, on the other hand, are efficient but do not tackle the very small contaminants. They will clean the air of particles that are 2 microns and larger. This will include pollutants such as dust. So if you’re looking to have a less dusty home then look for an air purifier with a HEPA filter, it will do a good job. What it won’t do is get rid of extremely small pollutants.


The true HEPA filter will put a bigger hole in your pocket than a HEPA filter. This may be a deterrent but it is important that you know what you need before letting the price guide you. Whilst the true HEPA filter may be pricier, it is also more efficient in cleaning the air of smaller particles.

The difference in price has also made the HEPA filter a more common feature on moderately priced air purifiers. Whilst the true HEPA filter will be on the higher end air purifiers, such as HVAC systems


What could be better


Hepa filters may clean the air of particles so small they cannot be seen by the naked eye, it still will not clean the air of anything smaller than 2 microns. This means that very small particles such as viruses and bacteria, which can be potentially lethal to the lungs, can still get through.


A true HEPA filter has many things going for it. However one of the downfalls that it has is that it is that is on the higher end of the pricing scale. If the budget is not an issue, then you will not have trouble with this filter’s price.

Similar Features

They are both effective in cleaning the air of most of the contaminants that you will find indoors or in your car. One has medium efficiency whilst the other has high efficiency

Both filters can be used for households to clean the air.  

Key Differences 

  • Filtration efficiency is the most obvious difference between the HEPA filter and the true HEPA filter.
  • A HEPA filter will clean the air of 99% of air contaminants whilst a true HEPA filter will get rid of 99.97% of air contaminants.
  • A HEPA filter gets rid of particles 2 microns and larger. A true HEPA filter gets rid of much smaller particles which are smaller than 0.3microns in size.
  • A Hepa filter has medium filter density whilst a true HEPA filter has high filter density.
  • A HEPA filter has a Merv rating of between 13 and 16 whilst a true HEPA filter has a Merv rating of between 17 and 20.
  • A true HEPA filter is considerably higher priced than a HEPA filter. 
  • The quality of filters may also vary according to the manufacturer.

 The verdict

The filter that you choose to go with, needs to tackle the problem that you have to deal with. The two filters deal with different sized contaminants. If you want to clean the air of any pollutants that are about 2microns in size and bigger, such as dust and pet dander, then the HEPA filter will do the job. If you are looking for a more affordable filter, you will also want to go with the HEPA filter.

However, if you will be looking for an air filter that can capture very small air contaminants such as mold and viruses then you will need to get a unit with a true HEPA filter. Whilst it may be on the higher end of pricing, it is a good buy and has a high level of efficiency. Ultimately, the unit that you chose depends on your needs and your budget. We hope our comparison helps you find your best fit. Happy shopping!

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