Envinity Group

Giant air cleaner unveiled in Amsterdam by Envinity Group

The purifier can clean about 800,000 cubic metres of air per hour, tech start-up Envinity Group said.

"A large column of air will pass through the filter and come out clear," Henk Boersen, the group's spokesman said.

The filter had been showcased at an exhibition in Amsterdam.

"It's a large industrial filter about 8m [26ft 2in] long, made of steel... placed basically on top of buildings and it works like a big vacuum cleaner," Mr Boersen explained.