Delhi gets a smog tower ahead of critical smoggy season: Everything to know about how it works and its impact

The mechanism of the tower is a downdraft air cleaning system. (Image: Twitter/ Arvind Kejriwal)

Smog tower: Delhi’s “smog season” is a couple of months away and, as previous years have demonstrated, the national capital requires some kind of intervention to tackle this issue. Accordingly, on Monday, the city got a ‘smog tower’ behind the Shivaji Stadium metro station so that it can help in better combating the issue of air pollution that Delhi witnesses every year. According to a report in IE, the entire structure has a height of 24 metres, including a concrete tower 18 metres high, with a canopy on top that has a height of 6 metres. Collectively, the structure is about as tall as an eight-storey building.

The base of the structure contains a total of 40 fans, 10 fitted on each side, and each fan has the capability of discharging 25 cubic metres of air every second. This means that as a whole, the tower has the capacity to discharge a whopping 1,000 cubic metres of air per second. Not only that but inside the tower are 5,000 filters placed in two layers. Both the fans as well as the filters have been imported from the US, the report added.

The mechanism of the tower is a downdraft air cleaning system. The system was developed by the University of Minnesota in the US, and IIT Bombay paired up with the university to duplicate the technology in India. The project was implemented by Tata Projects Limited. When the fans at the base of the tower start working, the air gets sucked in from the top of the tower at a height of 24 metres. It travels downwards, going through the two filters, in which the macro layer filter traps particles that are 10 microns in size or larger and the micro layer filters out particles of about 0.3 microns. The filtered air is then released at the bottom of the tower through the fans at a height of about 10 metres.

A computational modelling carried out by IIT Bombay has suggested that the tower could impact the air quality in a range of 1 km from the tower. However, the actual impact would be measured by IIT Bombay as well as IIT Delhi in a pilot study over a period of two years. Moreover, an automated SCADA or Supervisory Control and Data Acquisition system has also been included in the tower, and it would monitor the quality of the air, including levels of PM 2.5 and PM 10 particles, temperature as well as humidity. These metrics would be monitored continuously and displayed atop the tower.

However, as per experts, there is not sufficient evidence that would prove that such smog towers are effective.