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Calculate your way to Clean Air

All HEPA purifiers will clean the air for you but a little research will ensure you are getting the most clean air for your money and that it will be effective for the size of YOUR room. We have 3 calculators to help you with your research, plus some top tips:

  1. Work out how many air changes per hour (ACH) you will get for your room size

  2. Compare 3 different air purifiers to see how cost-effective they are in a 15m3 room

  3. Need 5 air changes per hour for a school or business? This calculator tells you the total CADR you need for your space so you know how many purifiers you need, or how powerful it has it be


Top tips for choosing an air purifier:

  • Not all companies want to give you the Clean Air Delivery Rate (CADR). While it has flaws, it is the only way that you, the consumer, can compare air purifiers. If you can't find it on the manufacturers website, do a search as most companies will have it whether they publish it in the UK or not

  • CADR figures are based on the top speed but due to the noise levels, purifiers are generally run on 'low'. Find out what the actual CADR figure is for the lowest setting to see if it is powerful enough for your space

  • Use the ACH calculator (1) to work out how much time it takes to clean the air. Run the purifier on 'high' for this long to clean the air once, then turn it down to a lower setting

  • If you need to filter out fumes from outdoor pollution, you will need a carbon filter. Our purifiers have activated charcoal granules and high airflow - tests show that our CADR figures will be reduced by 11% if you choose our Chemical Warfare packages

  • Think about whether it is worth the exposure to UV or Ozone (ioniser purifiers) when all you really need for clean air is a fan and a HEPA filter

  • Don't get fixed on claims about PM0.3. ALL HEPA filters will capture virtually 100% of nanoparticles (including viruses). PM0.3 is the smallest size that travels in a straight line so is the hardest size to capture, not the smallest! HEPAs are graded on their ability to trap PM0.3

  • The higher the HEPA filter grade, the lower the airflow and you really need a good airflow for clean air. We did a head to head test using the H11 and H12 filters in the Sqair, and then looked at what this means for an average bedroom size of 12m² .  The H11 filter resulted in higher ACH of 12 which meant the H12 was more effective at reducing PM0.3 and above for the first 5 minutes only!

We provide the technical figures for the Sqair and our commercial air purifiers on all speeds.

1. Air Change per Hour (ACH) calculator

RESULT ONE: Volume of clean air for every £ spent on your purifier


RESULT TWO: No of Air Changes per Hour (ACH) for your room size


RESULT THREE: Time it takes to clean the air at that setting (if you only have one CADR, this will be for the highest setting only)

NB: If you have 3 CADR numbers for Dust, Pollen & Smoke, use the lowest which is Smoke or Formaldehyde

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