How to Choose a Commercial Air Purifier in 2022

COVID-19 and air pollution have forced businesses around the world to turn to air purifiers to make their air safe. But larger spaces need larger more powerful commercial air purifiers. Let’s take a look at the important things to know when buying a large commercial air purifier.

What to Look For in a Commercial Air Purifier

Below are the key features and things to think about when purchasing a commercial air purifier.

HEPA filter

All HEPA filters can trap particle pollution including viruses and nanoparticles. Some purifiers are marketed as being able to capture smaller than PM0.3 but you don’t need patented technology for this. Our short video will hopefully dispel any myths around PM0.3.

How HEPA Filters Work? (Smart Air)

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Carbon filter

Add a carbon filter to clear the air of gases and chemicals – also known as volatile organic compounds (VOCs). If you are close to a busy road, wood-burning or factories, you might be concerned about chemicals in the air as it will find a way indoors even with the windows closed. You will also have chemicals in the air if your room has been newly painted, has new furnishing/flooring, or if you use chemical cleaners.

In these cases, opt for a purifier that has a carbon filter with granulated activated charcoal rather than a light smattering on fabric. The inclusion of a carbon filter will create additional resistance to airflow so your purifier should have a powerful fan.


A pre-filter protects the HEPA filter from larger particles such as dust and hair, and in doing so, prolongs the life of your HEPA filter. The great thing about pre-filters is they can be washed and cleaned periodically, unlike HEPA filters. But because they add an extra layer of resistance to your air purifier, they can reduce airflow and increase noise so won’t work with all purifiers. After running numerous tests, it decreases the performance of the Sqair but our commercial purifiers, with large centrifugal fans, are stronger so a pre-filter doesn’t affect airflow as much.

Forget the hype about ‘medical grade’ commercial air purifiers

Don’t be fooled by the marketing hype for ‘medical grade’ commercial air purifiers – there is no standard. Most companies don’t sell to hospitals but use this name to make their purifier sound fancy. Also, check the claims of purifiers using UV lights (few are strong enough to be effective at all) and ionizers (which emit ozone).

Check the Clean Air Delivery Rate (CADR)

You just need two measurements to work out the volume of clean air your purifier will deliver – 1) the dimension of the room you wish to use it in 2) the CADR which the manufacturer provides. Our calculator takes the cost of the purifier, your room dimension, and the CADR to calculate the true cost of clean air. Works for any air purifier so do your research before purchasing a purifier.

Work out the number of Air Change per Hour (ACH)

The ACH tells you the number of times each hour that the air in a room is replaced with completely clean air. For example, a value of ‘5’ ACH means a room’s entire volume of air is replaced with clean air 5 times in one hour. Most schools will typically have 1.5 ACH with the windows closed. Check out our online ACH calculator to work out how many air changes you will get from any purifier.


Most companies provide the CADR and airflow on high settings only. Our experience shows that purifiers are generally run on low or medium settings due to the noise levels. Schools tend to favour a maximum decibel level of around 50dB in order to be able to hear a class over the running noise of an air purifier. When researching air purifiers, check the CADR and the noise levels at all speeds. If the information isn’t published, ask the manufacturer.

Using an air purifier with the windows open

If your ventilation strategy includes always opening windows and/or you are worried about the outdoor pollution levels, our tests show our air purifiers are still effective with the windows open.

Designing a commercial air purifier

From its humble beginnings as a supplier of DIY purifier components, Smart Air has used years of experience, testing, and data to create two commercial air purifiers.

Meet the Blast Industrial Air Purifier

The Blast industrial air purifier has been stripped down to the essential features – a super fat HEPA filter and a crazy powerful fan. How fat is ‘super fat’? The Blast Mini has an impressive area of 11m2 when open. So how does this simplicity translate into real-life effectiveness?

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We have tried to keep the prices affordable and as far as we can see, our commercial purifiers are top of the range in terms of clean air delivery and noise levels. It is also cheaper than other purifiers in the same class.

A Technical Performance Overview of the Blast Mk ll Air Purifier

Blast Mk ll Air Purifier - Technical Performance Overview

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The Blast is used in hospitals and businesses around the world

What’s Next?

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Smart Air is a social enterprise and certified B-Corp that offers simple, no-nonsense air purifiers and provides free education to protect people from the harms of air pollution. We are proud to be the only certified B-Corp dedicated to fighting air pollution.

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