Fan filter units failed quality tests

All fan filter units tested by Shanghai's quality watchdog failed tests for substandard air purifying effect or potential safety hazards, officials warned.

Fan filter units — a type of motorized air filtering equipment — are widely used in industrial fields and many businesses claim they perform better to purify air than common air purifiers used at home.

On online shopping sites like Tmall and JD.com, customers have a choice of nearly 1,000 types of fan filter units for sale, priced between 1,500 yuan (US$230) and 2,500 yuan. Some types sold more than 1,000 monthly. Many claim they have a clean air delivery rate of over 1,000 cubic meters per hour — an index measuring the capability of purifying PM2.5 and formaldehyde.

However, tests found that nine out of the 13 models randomly bought on Tmall and JD.com have no effect in purifying formaldehyde, and the best only managed to score 30 percent of the effect compared with what is indicated on its label, according to the Shanghai Quality and Technical Supervision Bureau.

The purifying effect of PM2.5 tested on 11 units was under 60 percent of what's indicated on the label.

All the units were also found unsafe because of design flaws with some electrical parts not fully protected, the bureau said. The fan filter units included ACZ, Wantu, Aireer and Duolang brands.