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Which? Don't Buy air purifiers

by Matt Stevens

We reveal the air purifiers that don’t remove pollution effectively from the air.

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Our tough independent lab tests help us find the air purifiers that are the best on the market – the ones you can rely on to quickly and effectively remove pollutants, such as dust, smoke and pollen from the air.

But the same tests also uncover the air purifiers that do a pitiful job of extracting polluting particles. One of the 10 air purifiers we’ve tested was so poor at extracting pollen and smoke in our tests that its scores can’t be reported, as they were too low to be officially recorded. This air purifier was at least four times less effective at extracting dust from the air than the next worst machine on test.

Air purifiers aren’t cheap – they start from just over £100 and go right up to more than £600. So, make sure you don’t waste your money. We’ll help you to avoid the air purifiers that are a letdown our tests, and instead choose from the air purifiers that clean the air in your home the best.

Log in now or sign up for a £1 trial to Which? to unlock our full list of Don’t Buy products on this page. You’ll also get access to our air purifier reviews and all the reviews on our website.  

What makes a Don’t Buy air purifier?

If you suffer from allergies, or perhaps live beside a busy and congested road, you might want to consider an air purifier to clean the air you’re breathing in your home.

But not all air purifiers are equal when it comes to air purification and their ability to quickly and effectively extract pollutants. One air purifier we tested didn’t clean air quickly enough for it to be worth buying, and that’s why it’s a Don’t Buy.

What does a good air purifier look like?

A good air purifier is powerful enough to quickly remove polluting particles from the air in your home, it will be easy to use, it won’t make too much noise when working on full-power and will be almost silent on its lowest setting.

With a wide range of air purifiers to choose from, it might seem tempting to opt for an affordable-looking machine with impressive air-cleaning claims.

But our tests have shown that you need to look beyond manufacturers’ claims to be able to determine which air purifiers deserve space in your home, and which ones are best left on the shop shelf.

Unique air purifier testing by Which?

Which? has reviewed the latest air purifiers from brands, including Bionaire, Blueair, DeLonghi, Dyson, Electrolux, Homedics, Meaco, Philips and Vax.

Our expert lab assessments are based on six decades of product-testing experience. We examine the features of each air purifier, and test how well each model removes dust, smoke and pollen from the air in our specially built test chamber. We also check how easy each air purifier is to use, including how straightforward it is to remove the all-important filters.

  • We test each air purifier’s ability to clean air to an industry-recognised standard.
  • We measure exactly how many polluting particles are removed by each air purifier we test. The best air purifiers will remove more than 90% of the particles from the air, but poor machines can only manage 44%. The worst remove so few that we can’t officially report on the percentage.
  • We buy every machine we test and our tests cover a wide range of brands and sizes, so you can be sure we’ll always recommend the right air purifier for you.

If we find that an air purifier is bad enough to be a Don’t Buy, you can be sure that it’s one to avoid. No matter how attractive the price may be, it won’t do a good job in your home and is best left in the shop.

You can unlock this page and find out which air purifiers are Don’t Buys and which are Best Buys by taking out a £1 trial to Which?.

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