Shopping For Top Rated Air Purifiers in Shanghai

How to shop for top rated air purifiers: a Shanghai expat's guide

So, how to choose a suitable air purifier, aka air cleaner, to combat Shanghai air pollution? In our Shanghai Pollution article, we discussed some issues related to buying air purifiers in Shanghai.

Here we will go more into the technical details of air purifier machines and offer some advice on how to use them to best clean your indoor air.

A first suggestion is to buy air purifiers in Shanghai as quickly as you can. When air pollution spiked here in late 2015 and early 2016 sales of air purifiers in Shanghai soared by 300%, causing some air purifier stocks to run out, and prices to increase. 

We have a list of suppliers of air purifiers in China for you to compare, as well as useful resources and related news items at the end of the article. 

More Air Pollution Solutions

HEPA Filter

It is quite clear from experts that top quality air purifiers should include a HEPA (High Energy Particulate Arresting) filter to improve your indoor air quality.

Based on the United States Department of Energy (DOE) standard, HEPA filters remove a minimum of 99.97 percent of particles 0.3 microns in diameter. The European Union's standard, EN 1822:2009, breaks HEPA filters into several classes with efficiencies ranging from 85 to almost 100% for 0.3 μm sized particles. 

This particle size is much smaller than the maximum size of 2.5 μm associated with the hazardous PM2.5 pollutant we often hear about. PM2.5, aka fine particulate matter, is considered dangerous to our health, as it is small enough to breathe deep into our lungs and enter our bloodstream, as opposed to PM10 which includes particles from 2.5 to 10 microns in size which are mostly exhaled from the lungs.

The size of 0.3 μm was chosen for testing as it is considered the most penetrating particle size (MPPS), ie. the size of particle which filters have the most difficulty in blocking from passing through. Efficiency of the HEPA filter can actually increase for some types of particles smaller than 0.3 μm; although not all. 

HEPA filters can trap various kinds of particulate matter that cause or aggravate asthma and allergies including: 

  • dust
  • pollen
  • soot 
  • pet dander
  • dust mites
  • mold spores
  • some viruses and bacteria

Some air purifiers claim to use a HEPA ‘like’, ‘style’ or 'type' filter, but do not meet HEPA standards. So don't be fooled; make sure to purchase a machine with a true HEPA standard or above filter. 

Activated Carbon Filter

Chemical fumes, gases, chemicals in smoke, odor molecules, and some viruses, are much smaller than 0.3 µm and can pass through HEPA filters. It is important, therefore, for your Shanghai air purifier to also have an activated carbon filter.

Activated carbon has a very large surface area which attracts and absorbs gasses, fumes and vapors.

When air is pulled through the air purifier, the activated-carbon filter holds on to pollutants including:

  • VOCs (Volatile Organic Compounds) including formaldehyde and methylbenzene produced by off-gassing from building materials, furniture, flooring, paint and fabrics. 
  • Vapors emitted from cleaning and beauty products.
  • Chemical gasses found in smoke from cigarettes and forrest fires.
  • Emissions from burning of fuels such as sulphur dioxide, nitrogen and lead.
  • Some bacteria and viruses too small for HEPA filters.
  • Ground-level ozone (O3) which can cause respiratory illnesses can also be reduced when using activated carbon filters as O3 is created by chemical reactions with VOCs. It can also be decomposed directly by the activated carbon. 

Carbon filters also extend the life of the HEPA filter by trapping larger particles before they can reach it.

Choosing Top Rated Air Purifiers

Important points to compare when purchasing an air purifier in China:

  • The filters, and their efficiency to remove PM 2.5 and other pollutants.
  • Energy efficiency – most quality machines use much less electricity than air-conditioners, so won't cause a huge increase in your power bill, even when using several machines left on continuously.
  • Area coverage – Remember that most air purifiers are only cleaning the air that passes through its filters so make sure you get a machine with big enough capacity for the whole room. One option to consider is buying two cheaper smaller capacity machines for each side of the room rather than one large more expensive machine; especially as you are recommended to place the machine in the corner of the room.
  • Life span of filters. This can make a big difference to the cost of operating a machine over its lifetime.
  • Replacement filter cost: It is usually recommended to buy filters from the original manufacturer of your air purifier. However, in China several local companies such as Airfriend manufacture and sell replacement filters at lower prices for Sharp, BlueAir, Honeywell, and Philips purifiers. On its TMall site, Airfriend displays official test certificates to show their replacement filters meet high filtration efficiency. The author has used such filters which performed well based on tests with a Laser Egg pollution monitor.
  • Lights – sensitive sleepers report being irritated by the bright LED lights. Some machines have the function of dimming or turning off the display panel.
  • Noise – Most machines are slightly noisy on the high setting, but medium setting is usually quite acceptable and can produce a calming background noise to help you sleep.
  • Ozone emitting air purifiers – this technology was common in the past, as an active way to destroy pollutants in the air, but has largely been discredited due to health concerns. Shanghai’s quality watch dog has done tests for ozone production and banned several locally made models which exceeded safe emissions
  • Ionizer filters – some manufacturers offer this type of filtration, which turns a passive air purifier machine into an active machine by sending out ions which attach to allergens in the air which then stick to the floor, walls or other surfaces. It is important when choosing such a technology to make sure it does not produce unhealthy amounts of ozone. One manufacturer, Sharp, has gone one step further with its exclusive Plasmacluster technology. Plasmacluster creates combined positive and negative ions which are showered around the room attaching themselves to various particles in the air and oxidizing them. Some germs, bacteria, viruses, and mold are killed in this way. Sharp's tests show ozone emissions are well below permitted levels. However, by itself ionizers are not considered to be very effective for air filtration so be sure any air cleaner using such technology also includes HEPA and Activated Carbon filters. 
  • Ultraviolet air-purifier technology – Used to kill bugs, viruses and bacteria. Some machines use this technology to further sterilize the air inside the machine, whereas other machines claim it can sterilize the air actively throughout the room. Such bulbs need to be replaced thereby increasing cost. 
  • Humidifier – Air-purifiers also dehumidify the air during their operation. This can be a great benefit during humid summer months, but an issue during the dry winter season. Some suppliers recommend you buy an extra humidifier to be used in the winter, while some manufacturers, such as Sharp, have machines that include a built-in humidifier.
  • Pre-filter – some machines offer one or more levels of pre-filters to stop large particles before passing through the HEPA and carbon filters. This can extend the HEPA filter lifespan. The pre-filter will quickly get dirty and require regular cleaning or replacement; a simple and cheap task, after just a few weeks of operation in China, proving its effectiveness.
  • Housing and wheels – some offer steel housing, while others use plastic housing, which has advantages and disadvantages for mobility, durability and other considerations.
  • Automation – some machines offer many automation features, such as air quality sensors that can give you an indication of the level of dust and odors in the room. Such sensors can be helpful to automatically adjust the speed depending on room air quality, or inform you when it is time to change filters.
  • Air-cleaning capacity – how many times the air in the room can be circulated through the machine and cleaned in one hour (air-flow rate).
  • CADR resultsClean Air Delivery Rate-  this is one attribute tested by the Shanghai Quality Inspection and Supervision Bureau for approving air purifiers to go on sale in Shanghai. Overseas, however, while some experts consider this an important attribute others point out its weakness in rating the quality of an air purifier.
  • After sales service – the better quality the machine the less you should need after sales service, but it is also something to consider.

Prices of Top Rated Air Purifiers in China

Unfortunately, most foreign brands of top rated air purifiers in China are more expensive than in the West. The author bought a purifier with multiple filter layers for allergies manufactured by IQAir of Switzerland in Canada for about RMB 6,000, whereas in China it costs about RMB 14,000. Despite its high price, the CEO of IQAir expects China to become its biggest global market in 2019.

Other top rated air purifiers targeting the expat community in Shanghai include Blueair from Sweden, which was recently acquired by Unilever. Its purifiers, using their unique HEPASilent technology, sell between RMB 3,500 and 7,000, depending on the coverage area. Alen Air of the US is another popular brand in China selling various models between RMB 4,000-7,000. And Dutch company Philips sells air purifiers here from RMB 2,000-5,000. 

Several Japanese and Korean air purifier brands also sell well in China, but mainly target the local population so don’t have very good English marketing materials.

These include the Japanese brand Sharp with their built-in humidifiers selling between RMB 1,500 to 5,000. The author purchased one model with a coverage area of 40-60 m2 in 2013 for RMB 4,100. In 2019 the same model was purchased for just RMB 1,700. Not only had the price dropped by almost 60%, but it was upgraded to include smart control through an app. The humidifier is especially useful in Beijing which is extremely dry during the winter months. Of course humidifiers can also be purchased separately quite cheaply.

DIY Cheap Air Purifiers in China

An American expat, Thomas Talhelm, and his Beijing company Smart Air have been promoting their Do It Yourself (DIY) cheap air-purifiers to the expat community around China.

Instead of buying an expensive air-purifier in China, this company recommends buying HEPA filters by themselves and strapping them to a fan. Their own extensive test results show that PM2.5 levels in the room will be reduced as effectively as when using the more expensive purifiers.

Smart Air sells the kit for you to assemble yourself, or describes how you can purchase the parts on your own. This very smart idea gives those on lower budgets a way to reduce particulate matter (PM) levels indoors and therefore is a great contribution to making cleaner air more affordable for everyone in China.

However, Smart Air's inference that this method proves other air-purifier companies in China are “trying to pump people for insane profits” is a bit simplistic. The original Smart Air product is only a HEPA filter and does not include the activated carbon and other filters found in more expensive machines. Adding such filters to the Smart Air product will increase the price. Without the casing it can also be noisier than other air purifier machines. 

Smart Air recommends the standard HEPA filters they provide be changed within less than 2 months when operating 24 hours a day, while the long-life true HEPA filters in the more expensive air-purifiers, when combined with activated carbon and pre-filters, only need to be changed once every 2-5 years according to their manufacturers.

Air Purifier Rental Model

Another Shanghai expat startup, Mila, has come up with its own subscription model for renting air purifiers in Shanghai. This could be a cost effective choice if you are in Shanghai for just one to two years.

Cheap Chinese Air Purifiers

As the air purifier market in China grows and matures, foreign brands have been reducing their prices and more local Chinese brands such as MI from Xiao Mi have brought out machines selling for under RMB 1,000.

Unfortunately, few of these local brands have good English service in Shanghai, so it is hard to tell if their technology and service is as good as established Western brands. We, however, include some in the list below. 

Time To Replace or Clean Dirty Filters

Air Purifiers Fail Quality Tests in China

In early 2016 a report from the Shanghai Quality Inspection and Supervision Bureau showed that several cheap Chinese air purifiers, including some models made by Xiaomi, had failed quality tests.

Consumers were reminded to look for the required labeling of coverage area, clean air delivery rate (CADR) and noise index on the packaging before deciding which model to buy.

Further tests of air purifiers around China conducted by the national General Administration of Quality Supervision, Inspection and Quarantine in the first half of 2016 found that one-quarter of the them were substandard. The failed models were mostly smaller local Chinese air purifier brands. 

These national tests included tests conducted in Shanghai which found air purifier models manufactured by, sold by, or branded Mitsubishi, Baomi , Novowater, ReFinAIR, Somputon, Zhejiang Benyuan Appliance, LongYea, were substandard for various reasons.  

The Shanghai Consumer Rights Protection Commission carried out their own tests on 20 popular air purifier models sold in Shanghai in late 2016, and found several models failed standards for filtration efficiency for formaldehyde including models from Panasonic, Hitachi and several local brands. 

China grades filtration efficiency for pollutants between 35 and 50% as Grade C; between 50 and 65% as Grade B, and 65% and above as Grade A. Anything less than 35% efficiency is below standard. Manufacturers must also label their efficiency rates on their machines clearly for consumers, and must achieve at least 90% of this claimed amount when tested independently.

In 2017 the Shanghai Consumer Rights Protection Commission tested 20 models for their CADR rating and found that a model by Dyson achieved a very low score of just 134 (CADR unit of m3/h).

In subsequent tests published in late 2018 and early 2019 by the Shanghai Consumer Council and the Association of Environmental Protection Industry of Shanghai all models passed standards for particulate matter filtration efficiency, but several failed standards for formaldehyde or methylbenzene removal. A Panasonic model failed to reach the minimum standard for formaldehyde removal, and a MI model failed the minimum methylbenzene removal requirement. 

Many of those that did pass, however, only achieved the minimum C grade of 35 to 50% removal efficiency. And several models failed reaching the minimum 90% of their label's claimed efficiency amounts. 

HEPA Replacement Filter

Airfriend Replacement Filters

Tips For Operating Top Rated Air Purifiers

  • Make sure to remove sources that cause indoor air pollution, such as poor quality furniture or paint which emit formaldehyde. Removing such sources of air pollutants is as important if not more than using top rated air purifiers.
  • It is recommended to have your indoor air quality tested in Shanghai by a professional company that can discover sources of air pollution in your home.
  • Cheap indoor air quality monitors are becoming easily available in China. Consider picking up one of these so you can monitor your own indoor air quality.
  • Although top rated air purifiers are more effective in cleaning indoor air when windows are closed, from time to time you should still open windows to ventilate the room with fresh air. So keep an eye on AQI readings in your location to let you know the best time to ventilate.
  • The purifier should not be placed too close to walls. Check the product manual for best positioning of the machines.
  • When first turning on your air purifier, set it on high for at least 30 minutes to effectively cleanse the entire room's air, and then switch to medium if it is too noisy.
  • The air purifier should be kept on 24 hours per day for best results in polluted environments.
  • Make sure to check the filters regularly and replace them when required.
  • Before turning on the air purifier after a period of non-use, first check to make sure the machine and filters are clean.
  • Low setting is often not sufficient to keep the room air clean, so medium to high is preferred.

China Air Purifier Supplier List

China air purifier suppliers:

Chinese Air Purifier Brands:

Non-original Brand Replacement Filters for Top Rated Air Purifiers:

Indoor Air Quality Testing in Shanghai:

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