World's largest air purifier now cleaning up smog in Xi'an?

China is currently testing out its latest weapon in the fight to make skies blue again: a 100-meter-tall smog-sucking tower.

Dubbed the “world’s largest air purifier,” the tower was completed last year in the city of Xi’an and appears to be having at least some success in improving the air quality in the surrounding area, according to preliminary results obtained by researchers at the Institute of Earth Environment at the Chinese Academy of Sciences.

The South China Morning Post reports that the project’s head, Cao Junji, has credited the tower with a 15% reduction in PM2.5 levels during times of heavy pollution, producing more than 10 million cubic meters of clean air since its launch a few months ago, and helping to clean the air, somewhat, over an area of around 10 square kilometers.

It’s worth noting that these results are only preliminary with a more detailed assessment set to be released in March. Still, Cao couldn’t help but boast: “The tower has no peer in terms of size … the results are quite encouraging.”

While its efficacy is still up for debate, it’s certainly impossible to argue that the tower is not big. Around the base, there are a number of glass “greenhouses” spanning the area of half a football field, which suck polluted air in before heating the air up with solar energy, causing the hot air to rise and pass through layers of cleaning filters inside the 100-meter-tall tower.

China’s ancient capital of Xi’an has a reputation for being one of China’s smoggiest cities, particularly during the wintertime when coal furnaces are switched on. Back in 2014, the city invested 900,000 yuan into smog-fighting water cannons, a method that has seen only little, temporary, and very localized success in cleaning up the air.

The idea for colossal towers that would suck up the smog also dates back to 2014, while the Xi’an project first made headlines in May 2016 when photos of the tower under construction in the city’s Chang’an District were published online. It’s not clear how much the project is costing the city.

Dutch artist Daan Roosegaarde has pioneered the concept of smog-sucking towers, albeit on a much smaller scale. In October 2016, Roosegaarde’s company installed a 7-meter-tall “Smog Free Tower” in Beijing which promised to turn the city’s dirty air into diamonds.

Thus far, the tower has seen mixed reports about its success in cleaning up the nearby air with one expert calling it “just a kind of performance art.” However, a Chinese environmental technology company has seen promise in the idea, announcing last year that it had partnered with Roosegaarde and would begin producing the towers.

Meanwhile, those involved in the Xi’an project see the 100-meter-tall tower as just the beginning. According to the SCMP, Cao hopes to one day build “full-sized towers” in other Chinese cities which would soar up to 500 meters in height and be surrounded by a seemingly impractical “30 square kilometers” of greenhouses, making it powerful enough to purify a small city’s worth of air.

And, hey, if super smog towers don’t end up working out, there’s always the concept of giving 15 million people large handheld fans and telling them to all start fanning in the same direction on the count of three.

[Images via Shaanxi Daily]

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