Engineers and designers in the Netherlands have created the world’s largest air purifier in the form of a free-standing tower that extracts smog from the surrounding atmosphere.

The Smog Free Tower stands just over seven metres in height and is capable of purifying as much as 28,300 cubic metres of air within the space of just an hour.

The tower cleanses polluted air of smog particles by means of an ionization process that members of its development team have been researching for more than a decade.

The air is first extracted it from the atmosphere via a wind-powered radial ventilation system situated at the apex of the tower. The tower then channels the air into an internal chamber and uses an ionization process to impart microscopic smog particles measuring less than 15 micrometres with a positive charge.

Scientists have proven that airborne smog particles under this size threshold pose the greatest threat to human health, as they are small enough to be inhaled and cause damage to the respiratory and coronary systems.

Once the particles are imbued with a positive charge the tower then removes them from the air using a grounded counter electrode, and expels the resulting clean air via vents at its base.

The result is a microclimate of clean air within the immediate vicinity of the tower, as well as cleaner air in the broader environment if a sufficient number of the structures are permitted to operate simultaneously for long enough periods.

The Smog Free Tower is the product of collaboration between innovative Dutch designer Daan Roosegaarde, Bob Ursem from Delft Technology University, and green tech company European Nano Solutions.

Roosegaarde has already garnered renown for some of his ground-breaking innovations in other areas of urban development, including the Netherlands’ Smart Highways which convey information to drivers via luminous signs embedded within road surfaces themselves.

His latest project has already drawn the attention of municipal officials from major cities around the world, including Beijing, Mexico City, Mumbai and Paris, as well as property developers hoping to cleanse the air of more affluent urban neighbourhoods.