A group of researchers from the Institute of Earth Environment at the Chinese Academy of Sciences has designed and built an air-purifying tower in Xian, China. Measuring 328 feet in height, the tower seems to have improved the air quality of a four-square-mile tested area. According to a South China Morning Post article, the tower has produced more than “353 million cubic feet of clean air a day since its launch [a few months ago] … on severely polluted days the tower was able to reduce smog close to moderate levels.”

Smog and polluted air are sucked into a large, solar roof–covered greenhouse—which is about the size of a soccer field—that is built around the tower’s base. The polluted air is then heated using the solar power collected from the greenhouse roof panels. As it travels up the tower, the polluted air passes through various purifying filters, and the fresh air is released into the atmosphere.

The Xian air-purifying tower is part of a research project that was launched in 2015. The project's goal was to find a solution for artificially removing pollutant particles from the air. According to the same news article, more details will be released in March, including a performance assessment of the tower.