Best air purifiers 2018: Don’t let your allergies get the best of you

We’ve reviewed 10 air purifiers, but have put together a list of five that we recommend. Of these, two stood out.

The Vax Pure Air 300 Air Purifier has the highest clean ratings, and is suitable for large rooms or those with allergies. For smaller budgets and rooms, and those less sensitive to air issues, the HoMedics Brethe Air Purifier is an excellent choice.

Best overall air Purifier

Vax ACAMV101 Pure Air 300 Air Purifier - White

The VAX ACAMV101 Pure Air 300 is our pick of best overall air purifier as it has great automatic modes, powerful all-round performance and is quiet in its Night Mode.


How we choose the best air purifiers

The quality of air cleaning is the key feature of an air purifier. All air purifiers are capable of removing particulate matter (PM) from the air, which are the tiny particles responsible for triggering allergies, such as hay fever and asthma.

To demonstrate the quality of cleaning, the majority of air purifiers come with Clean Air Delivery Rate (CADR) ratings for smoke, pollen and dust. The higher the score, the better the performance. And, the individual ratings help you choose the right purifier for your needs.

However, not all manufacturers quote CADR ratings and, instead, quote the percentage of particles below a certain size: the higher the percentage and the lower the quoted particle size, the better.

Some – but not many – air purifiers are capable of removing Volatile Organic Compounds (VOCs) from the air, too. These are harsh chemicals that can be found in everything from old furniture to cleaning sprays.

To test an air purifier’s performance, we use a three-second burst spray from a can of insecticide – a source of particulate matter and VOCs – directed into the middle of the room. With the air purifier placed in a corner running at maximum, we time how long the air takes to return to normal, using a separate air-quality monitor.

We also test the sound levels of purifiers, running at minimum and maximum speeds from a distance of 1 metre.

Vax Pure Air 300 Air Purifier

1. Vax Pure Air 300 Air Purifier


  • Excellent filtration
  • Automatic mode
  • Quiet in night mode


  • Large
  • Fan didn’t turn off in auto mode

Looking like a fancy bin with an ashtray for smokers on top (760 x 320 x 320mm), the cylindrical Vax Pure Air 300 Air Purifier is attractive in glossy white plastic and is easy enough to place out of the way. It has a HEPA filter – designed to last three to six months, depending on usage – and an ionisation option. The purifier’s front panel is dominated by simple touch controls that let you power on the Air 300, control the fan speed, use the timer, and toggle the ioniser function. These options are replicated on the slim-line remote control.

The big indicator light on the front changes colour to display the current air quality, moving from green through amber to red. At minimum fan speed, I found the Vax Pure Air 300 ran at 35.9dB and a more intrusive 62.1dB at max. The night mode cuts the status lights and drops fan speed to a lower level, with sound falling to a quiet 33.4dB. Although it was still audible, you could easily sleep through its low-level noise. Power efficiency is excellent, with max power drawing a peak of 53.8W, and the minimum setting just 7.2W

Most people will find it easiest to run the Air 300 Air Purifier in automatic mode, with the device choosing the best fan speed to deal with current air conditions. I found that the fan never fully turned off, which is a little disappointing. Still, there’s a timer option – hourly increments of between one and eight hours – if you want the Air 300 to power down.

Regarding effectiveness, the Air 300 has high CADR ratings:428 (smoke), 392 (pollen), 278 (dust). In our synthetic test, it cleared the particulate matter from of our insect spray in 1min 8secs.

If you want a powerful all-rounder, this is the model to buy, and it’s suitable for rooms of up to 120m2. Those who want something quieter should buy the Philips Air Purifier Anti-Allergen with NanoProtect Filter AC3256/30.

Buy now: Vax Pure Air 300 Air Purifier for £279.99 from Amazon

Dimplex DXAPV3N

2. Dimplex DXAPV3N


  • Small
  • Well priced


  • Suitable for small rooms only
  • Quite loud
  • No auto mode

Not all air purifiers are giant boxes, as the Dimplex DXAPV3N demonstrates. This is a small box that’s designed to fit on a desk. It can clean an area up to 28m2, making it suitable for smaller rooms. It’s also one of the least expensive HEPA-filter purifiers available. To get the price down, the DXAPV3N is a rather simple product. It can’t display the current air quality; there’s no remote control; and there’s no sleep timer. There’s a carbon filter built in, designed to neutralise odours, and it emits negative ions to help reduce the risk of some viruses.

The operation is simple, using the two-speed dial on the side. At the maximum setting, I measured noise at 49dB; switching to the low-power setting, sound dropped to 47.4dB – which is still fairly loud. It’s a shame that there isn’t a quieter night-time mode. Power efficiency is pretty good, with the DXAPV3N drawing 24.8W at maximum power, dropping to 15.5W at minimum.

At maximum setting, the particulate matter from our spray of insecticide took just under five minutes to return to normal levels. That’s comparatively slow, and confirms that this really is a product for a smaller room. The official CADR ratings bear this out, with low ratings for smoke, pollen and dust: CADR ratings: 80 (smoke), 89 (pollen), 78 (dust). Each HEPA filter should last for around 2000 hours. There’s no warning to tell you when the filter needs replacing, so regular manual checks will need to be made.

If you have a small office or bedroom, the DXAPV3N could be a good choice. For larger rooms or more effective purifying, the Vax Pure Air 300 Air Purifier or HoMedics Brethe Air Purifier are better choices.

Buy now: Dimplex DXAPV3N for £59.99 from Amazon

Philips Air Purifier Anti-Allergen with NanoProtect Filter AC325630

3. Philips Air Purifier Anti-Allergen with NanoProtect Filter AC3256/30


  • Looks great
  • Powerful air purification
  • Automatic mode
  • Quiet


  • Comparatively expensive

The majority of air purifiers are rather drab-looking, but Philips has gone all-out with its Air Purifier Anti-Allergen with NanoProtect Filter AC3256/30. It looks great. Tall yet relatively thin, this air purifier is easy to tuck out of the way.

As you’d expect from Philips’ top-of-the-line air purifier, the AC3256/30 is packed full of features. For starters, it has a particulate matter (PM) sensor. Thanks to the LCD on top, you can accurately see the level of small particles currently in your home.

This model comes with two filters. There’s a NanoProtect filter that reduces odours and can filter some VOCs; it lasts for up to 12 months and replacements cost around £30. Then there’s the HEPA filter, which lasts for around 24 months with replacements costing around £40. Thankfully, the AC3256/30 notifies when both filters need replacing; if you don’t do the job within 14 days, the entire machine locks down to avoid damage.

All controls are accessed from the top, using the touch-sensitive panel. Unfortunately, there’s no remote control. Parents will be pleased to discover that there’s a child lock, stopping little hands from activating the device. From the control panel you can choose the fan speed, set the timer (in one-hour increments between one and 24 hours), and adjust the brightness of the controls.

Most people will find it easiest to operate the AC3256/30 in automatic mode, where the fan speed ramps up as the air quality deteriorates. There’s a standard Auto mode and a more sensitive Allergen mode. Usefully, the colour lamp at the front offers a visual indicator of air quality, moving from blue (good) through amber to red (poor). This lamp is dimmed when you dim the controls, so you can use the AC3256/30 in a bedroom.

At the lowest setting the AC3256/30 is silent, and I measured noise at 33.4dB – essentially, this is just regular background noise. At full tilt sound jumped to 56.7dB. Spraying insecticide saw PM levels drop back to normal in 1min 45secs. High CADR ratings in all categories show that this is a powerful air purifier, lagging slightly behind the Vax Pure Air 300: 234 (smoke), 253 (pollen), 226 (dust).

If you want a super-quiet air purifier, or a model that’s designed for pollen and allergies, then this is the model to buy. It’s suitable for room sizes up to 95m2. The Vax Pure Air 300 is slightly cheaper and a better all-rounder, but it doesn’t look quite as nice and it’s louder too.

Buy now: Philips Air Purifier Anti-Allergen with NanoProtect Filter AC3256/30 for £369.99 from Amazon

4. Dyson Pure Cool Link Desk


  • Works as a fan, too
  • Fantastic looks
  • Automatic control
  • Amazon Alexa, app and remote control


  • Not ideal for winter use
  • Expensive

The Dyson Pure Cool Link Desk is both a fan and an air purifier. In terms of fan performance, it’s everything we’ve come to expect from Dyson fans, producing a smoother blast of refreshing air compared to a traditional fan.

As the Link name suggests, this model connects to your Wi-Fi, providing control via the Dyson Link app. At its most simple, the app lets you control fan speed, set the timer (15m increments up to one hour, then hourly increments to nine hours), and toggle the Auto mode and oscillation. These controls are replicated on the remote control; there are no controls, bar a power button, on the main unit. And, you can now control everything using Amazon Alexa, too.

Since this is a purifying fan, the app lets you monitor air quality, temperature and humidity, enabling you to effortlessly flick between days to build up a picture of your home’s air health. Every time the fan is turned on, it will purify the air. There’s also an auto mode, which lets the Pure Cool Link choose its fan speed automatically when it detects poor air quality. Our insect spray turned the fan up to max, cleaning the particulate matter down to healthy levels in under two minutes.

The filter will need to be changed at around a year – at a cost of around £50 – although your usage helps define this. Fortunately, a count-down timer in the app tells you how many hours you have left, warning you when it’s time to make the change.

As we’ve come to expect from Dyson, the Pure Cool Link is quiet. At minimum setting, I measured the fan at 33.4dB (the same as the room’s background noise). At full speed, the fan jumped to 56.7dB. With ten speed settings to choose from, it’s easy to find the right balance between noise levels and cooling performance. Power consumption is good at 60W on max and 11.3W on minimum.

The Dyson Pure Cool Link Desk is rather expensive, but offers reasonable value if you want a fan, too. Dyson doesn’t provide room size or CADR ratings, but the Cool Link Desk would seem best suited to a regular room, as an accessory for a desk. If you want a larger air purifier with defined high CADR ratings then the Philips AC3256/30 or Vax Pure Air 30 may be a better choice.

Buy now: Dyson Pure Cool Link Desk for £399.99 from Amazon

Homedics Professional HEPA Air Purifier AR-20

5. HoMedics Professional HEPA Air Purifier AR-20


  • Effective purification
  • Slim design
  • Timer


  • No automatic mode

The HoMedics Professional HEPA Air Purifier AR-20 has a slim yet wide case, which makes it relatively easy to position out of the way. It’s a mid-size air purifier, able to take on rooms up of to 72m2. It’s one of the cheaper HEPA filter purifiers out there. Neatly, the filter can simply be vacuumed to keep it clean, with the Professional HEPA Air Purifier issuing a warning when it’s time to do this job via the LED indicator on the control panel. Replacements can be bought for around £20.

As you’d expect from a product at this price, its controls are rather simple. On top there are power, fan speed and timer controls; these are replicated on the slim-line remote control, too. There’s no automatic operation mode, nor an indicator to display the current air quality. However, you can run the unit on a timer so that it doesn’t over-run, selecting two-hour increments from two to 12 hours.

Running at maximum speed, the Professional HEPA Air Purifier managed to clean the PM part of our insect spray in just over two minutes, running at a fairly loud 62dB. Dropping fan speed to minimum, sound reduced to 42dB, which isn’t too bad and easy enough to sleep through. Power usage is a little high: we measured the Professional HEPA Air Purifier as drawing 78.6W on maximum and 43.4W on minimum settings.

CADR ratings are mid-range across the board, showing that this is an effective purifier for general use: 117 (smoke), 123 (pollen), 126 (dust). For a good-sized room (up to 72m2) where you want a simple air purifier, the Professional HEPA Air Purifier is a well-priced option. For larger rooms or more powerful purifying, turn to the Philips AC3256/30 or Vax Pure Air 300 Air Purifier.

Buy now: HoMedics Professional HEPA Air Purifier AR 20 for £64.99 from Amazon


That was our roundup of the best air purifiers. To find out more about how to choose the right model, keep on reading

Air purifier buying guide

Best air purifiers – What can air purifiers do?

Air purifiers use a fan to pull in dirty air at one end, remove pollutants, and output clean air at the other end. The exact pollutants that can be cleaned depend on the technology used. All of the air purifiers we’ve tested here use a HEPA filter, which will capture a minimum of 99.97% of airborne particles 0.3µm in size. Also known as particulate matter, these particles can penetrate your lungs causing respiratory problems, particularly in allergy sufferers.

Particulate matter sources include dust, with cleaning likely to disturb dust and throw it into the air, pet hair and dander, smoke and pollens. HEPA filters are no good where dust has settled, since the filters can remove only airborne particles. In other words, you still need to clean effectively. HEPA filters also have a lifespan, after which they’ll need to be replaced. The exact timing will depend on the air purifier and how dirty your air is, but expect to buy a new filter between three months and 12 months of operation.

Volatile Organic Compounds (VOCs) are harmful chemicals that are often found in cleaning products, paints, and some beauty products. VOCs are also found in some manufactured products, such as synthetic carpets and old furniture. Most air purifiers can’t touch these pollutants; those that can, can’t filter all VOCs.

Instead, you’re better off with an air monitor, such as the excellent Foobot, to monitor your home to see what’s giving off VOCs. Where possible, switch to less harmful products. Some models of air purifier also have an ionisation option. These use negative ions, which causes particles to stick to surfaces – such as wall or floor. Ionisation has been shown to reduce the risk of some viruses. Ionisation on its own isn’t particularly effective, so always combine with a proper air purifier.

Best air purifiers – What else should I look for?

All air purifiers use a fan of some description, so look for one that runs quietly enough for your intended use. We measure sound at maximum and minimum settings to help you choose. An automatic mode that ramps up the fan when the purifier detects dirty air is useful, as you can leave the purifier to do its job. You need to match the air purifier you buy to the size of room or space that you want to keep clean. Purifiers are rated by the square metre, so buy one that’s big enough.

Finally, you can look out for the Clean Air Delivery Rate (CADR), which tells you how effective the purifier is at different types of allergen, compared to introducing clean air. For example, an air purifier with a CADR score of 190 for dust particles is as effective as adding 190 cubic feet of clean air per minute. In short, the higher the CADR rating for each type, the better. And, CADR scores are comparable across all products, helping you make the right choice.

CADR has three main ratings to help you decide: smoke uses very small particle sizes of 0.09 to 1µm; dust has particle sizes of 0.5 to 3µm; and pollen uses particle sizes of 5 to 11µm. It’s best to choose your air purifier based on how effective it is at the pollutant you want to remove. Hayfever sufferers, for example, should choose an air purifier that’s efficient for pollen removal.

Finally, since air purifiers come in different sizes, the CADR rating should equal (or exceed) 2/3 of your room size in square feet. A 135-sqft room would need CADR ratings of 90 or above, for example.