| Air quality is a long-standing problem in China due to excessive coal burning and traffic as the population increases. Many cities including Beijing routinely face hazardous air pollution levels. Chinese technology firms such as Lenovo and smartphone maker Xiaomi have come out with smart air purifiers in a bid to expand in the connected devices market.
The sales of air purifiers reached 3.5 billion yuan ($458 million) in 2013, according to market research carried out by Daxue Consulting, which has offices in Shanghai and Beijing. "There [was] 80-100 percent growth year on year compared to 2012," said Matthieu David-Experton, CEO of Daxue Consulting. Over 40 percent of the 2013 sales were recorded during the months of November and December when air pollution levels were particularly high.
In recent years the air purifier industry has taken off with some extremely modern advancement. The use of electronically commutated (EC) fans enables energy savings of up to 70 percent compared with conventional air-conditioned (AC) fans. EC fans use intelligent electronics to precisely calculate how much energy is required to operate at different speeds. They are also fully speed-controllable, unlike AC fans which are limited to a number of set speeds. Another improvement is the fan blade design, optimized by manufacturers to produce less noise.
High-efficiency particulate air (HEPA) filters, which can remove 99.97 percent of airborne particles measuring 0.3 micrometer or more in diameter, and air filter materials with higher efficiency, longer life and lower pressure drop have become available on the market. Lower pressure drop refers to the resistance of the filter to airflow; less resistance means more airflow and increases in filtered air. Some filters use nanofibers, enhancing filtration efficiency.
In terms of future developments for the industry, Adam Elson, CEO of Ding Ding Group of Companies, the exclusive distributor of InovaAir purifiers on the Chinese mainland, Taiwan and Hong Kong, told ChinAfrica, "InovaAir is continuing to engage in research and development (R&D) to manufacture air purifiers with the aim of higher airflow, larger filter surface area using hi-tech filter materials to achieve this. Lower energy consumption and lower noise levels are also key R&D goals so the ongoing cost of operating the air purifier is kept to a minimum along with maximizing performance and user comfort."
Strict safety procedures have to be followed while manufacturing the air purifiers. Elson said philosophy is an important starting point to work from. His company's air purifiers are made from safe materials which do not produce harmful chemicals and volatile organic compounds. Many air purifiers are made from plastic and materials, which leach chemicals into the airstream.
Top of the range
High-range air purifiers are generally manufactured using state-of-the-art automated computer numerical control equipment to precisely cut and fold steel profiles which make up the air purifier bodies. All systems are also coated in a solvent-free and durable powder coat finish. The filters they use are all steel, employing a cylindrical cartridge design similar to that of commercial dust filtration systems, which makes them well suited to high air pollution environments. Steel is rolled and welded in place on all filters. The final assembly is by hand by highly trained technicians.
Although it is possible for people to manufacture their own HEPA filters at a low cost, more and more people are becoming aware of the harmful effects of pollution. Therefore it is no surprise that there have been huge surges in the sales of air purifiers in smog-hit countries around the world. Xiaomi is stepping into the home appliances market with a new air purifier that can be controlled via a mobile phone. The company recently unveiled its "Mi Air Purifier," which is on sale in China through its website. Like its other products, Xiaomi is selling the air purifier at a low price that could undercut its rivals - 899 yuan ($146). | 
