The best air purifiers to beat the smog

We give you the deets on popular indoor air purifiers for every budget

LESS THAN 1,500RMB

Smart Air

A no-frills solution to Beijing pollution, a Smart Air purifier is a fan with a filter attached to it using a Velcro strap – the brainchild of Thomas Talhelm as an affordable way to clean the air in your home. The team at Smart Air send you the pieces and you strap them together.

There are currently two purifiers to choose from, the Original DIY for rooms up to 15sqm and the larger DIY Cannon for rooms 'at least' 30.5sqm – both of which are said to hold their own against their fancier and pricier counterparts.

Filters Smart Air purifiers use Hepa filters and, according to test results published on the Smart Air website, the Original DIY clears out 92 percent of PM2.5 particles over three hours, while the Cannon DIY clears 89 percent of PM2.5 particles in a 30.5sqm room – or 96 percent of PM2.5 particles in a smaller area. Filters should be replaced every 140 days on the original model, with recommendations for more regular changes on the Cannon, as it filters air at a faster rate.

Settings Three fan speeds.

Extras Pre-filters are available for both models, and activated carbon filters are available for the DIY Cannon.

Price 200RMB for the Original DIY; 470RMB for the Cannon DIY; replacement Hepa filters 80RMB. Available at smartairfilters.com.

Xiaomi

As well as selling some of the best value smartphones on the market, Chinese tech firm Xiaomi has smashed its way into the clean-air market with its high-tech, high-design purifiers at competitive prices. The second-generation Xiaomi purifier, the Mi Air Purifier 2 seems to do the job without breaking the bank, despite no longer being the newest model on the market.

Filters The Mi 2 uses a cylindrical triple-filter system – with a pre-filter, a Hepa filter and an activated carbon filter – purportedly sucking up 99.7 percent of the nasty particles and the gasses in the air. According to Xiaomi’s tests, the air purifier can clean the air in a 21sqm room in ten minutes – and should still be effective clearing rooms up to 39sqm.

Settings Auto mode detects the air quality in the room and adjusts the speed; sleep mode only allows the purifier to run silently; and a purge function for extra-polluted days filters the air faster.

Extras A 'smart' purifier, the Mi 2 can be controlled remotely through the Mi Smart House app (available for Android and Apple phones). The app allows you to adjust the machine settings, see the levels of pollution in your house at any time and will eventually learn to automatically adjust the purifier’s settings depending on your routine.

Price 699RMB; triple-layer replacement filters from 159RMB. Available at mi.com, jd.com and xiaomi.tmall.com.

1,500 TO 3,000RMB

Philips

Well-trusted in the world of purifiers, Philips has a fair few to choose from, ranging from 700- 10,000RMB. The midrange AC074 and AC4076 – similar in design and function – have proved popular. The AC074 is said to effectively clean the air in rooms from 17-29sqm, while the newer AC4076 works in rooms from 22-38sqm.

Filters The purifiers come with a triple filtration system – pre-filter, Hepa filter and activated carbon filter. According to Philips, both purifiers remove more than 99 percent of PM2.5 particles, with the AC4074 and AC4076 pushing through 298 and 302 cubic meters of clean air per hour, respectively.

Settings Five fan speeds; auto mode; Smart Night mode silences the fan and turns the display lights off when lights go out; and BoostPower mode for heavily polluted days.

Extras A 'smart' display panel has coloured indicators for pollution levels in the room and when the filter needs replacing. It also has an auto lock that stops the machine working when the air quality from the purifier can no longer be guaranteed – such as when the filters need changing.

Price 2,449RMB for the AC4074, 2,999RMB for the AC4076; 488RMB three-pack replacement filters. Available at jd.com.

Sharp

Japanese electronics manufacturer Sharp's range of humidifier-purifiers might just be the answer to an onslaught of static shocks through the Beijing winter by keeping your home at optimum humidity (40 to 60 percent).

Depending on the size of the room, both the older KC-W280SW (effective up to 24sqm) and the slightly more powerful and slightly more expensive upgrade, the KC-W380SW (effective up to 32sqm), seem to do pretty much the same job.

Filters Both the KC-W280SW and the KC-W380SW are kitted out with long-life Hepa filters – that are said to last up to five years – and can remove 99.7 percent of harmful particles. Both models also come with a pre-filter and an activated carbon filter.

Settings Three fan speeds, a 'Quick Clean' function and auto mode.

Extras As well as having an inbuilt humidifier and a smart display, the KC-W280SW and the KC-W380SW both feature Sharp’s ‘Plasmaclusterion’ technology for extra filtration. Working alongside the mechanical filters, the Plasmacluster technology is said to release positive and negative ions into the room that break down and remove the tiny particles that traditional filters can’t catch – without producing any harmful 'ozone' like some ionizing purifiers.

Price From 1,699RMB for the KC-W280SW; from 2,999RMB for the KC-W380SW; replacement filters from around 500RMB. Available at jd.com or amazon.cn.

3,000RMB AND OVER

Blueair

Founded in Sweden in 1996, Blueair is one of the more established brands on the market, only dealing in air purifiers and filters. There are three ranges to choose from: Blueair Pro, Blueair Sense and Blueair Classic. While you could spend a fair amount of money on a Blueair purifier (up to 12,000RMB), the 270E Slim – an upgrade from the basic model – should effectively clear rooms up to 30sqm, performing best in rooms around 22sqm.

Filters The 270E comes with Blueair's signature 'HEPASilent Technology' particle filter, combining ‘electrostatic and mechanical filtration’ to get rid of 99.7 percent of particles down to 0.1 micron in size – with extra activated carbon filter sheets to help clear odours. On average, it will clean 300 cubic metres of air per hour. Filters should be replaced roughly every six months when the purifier is kept on 24 hours a day.

Settings Three fan speeds including one for nighttime and one for cleaning larger rooms, auto mode and a timer.

Extras The 270E can be controlled via a remote control and features a smart display panel with indicators for the pollution level and when to replace the filter – if you’re not phased by these additional functions, the flagship, basic Blueair 203 does the same job for half the price (from around 1,600RMB)

Price 3,680RMB; filters 296-398RMB. Avaiable at blueair.cn or world.tmall.com.

Origins

Concerned by China’s poor air quality and 'thoroughly disappointed' by other purifiers on the market, Beijing-based company Origins – alongside partners in Switzerland – designed its own OxyBox air purifier. According to the website, the OxyBox can 'deliver cleaner air than the air at the Rhone Glacier in Switzerland' to your Beijing home in 45 minutes.

Filters Especially designed for poorly sealed apartments in urban Chinese cities, the OxyBox is fitted with an activated carbon filter and a Swiss Snowline Microglass Hepa filter, which is said to allow for 'extremely high air flow while maintaining high particle arrestance', pushing through up to 350 cubic metres of clean air per hour. Rather than clearing 99 percent of particles, the Origins team proudly claim that the OxyBox clears 90 percent of particles, but at a faster rate – meaning it can 'clean a room full of smog, cigarette smoke or burnt food in about 30 minutes'. Filters should be changed roughly every nine months.

Settings Four fan speeds.

Price 4,499RMB; replacement filter set 970RMB. Available at originstech.com.

TECHNICAL JARGON

Hepa filter Standing for 'high-efficiency particulate air', Hepa is not actually a type of filter, but a standard for filter performance. Filters that reach Hepa standards can filter 99.7 percent of particles down to 0.3 microns in size – to put that into perspective, a grain of table salt is 100 microns.

Pre-filter The purpose of a pre-filter is to catch the stuff that the main Hepa filter can’t. It can also help to prolong the lifespan of the main filter by catching bigger particles that could otherwise easily block it. Most pre-filters can be washed to increase their lifespan.

Activated carbon filter Used as an extra form of filtration, activated carbons are very powerful absorbents. The main uses of an activated carbon filter is to clear the air of harmful harder-to-catch gasses or volatile organic compounds (VOCS) that can be found in the home. It is also good at getting rid of odours.

CADR The Clean Air Delivery Rate (CADR) signifies the volume of clean air pushed through the purifier. CADR is often measured on an average rate per hour in cubic metres. The ideal CADR will vary depending on the room size, but in general, the higher the number the better.

For a guide to the best apps to help you beat Beijing's pollution, hit 'Read more'.

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