The Nanjing Greenland Financial Center (Chinese: 南京紫峰大厦, also Greenland Square Zifeng Tower) is a 450-metre (1,480 ft) supertall skyscraper completed in April 2010 in Nanjing, China. The 89-story building comprises retail and office space in the lower section, and restaurants, a hotel, and a public observatory near the top. The tower’s stepping is functional, helping separate these sections. The mixed-use tower, which overlooks Xuanwu Lake, became the second tallest building in China and the 5th tallest building in the world when topped out in 2008. An observation deck on the 72nd floor, 287 m (942 ft) above ground, provides an unobstructed, panoramic view of Nanjing and the nearby Yangtze River, two lakes and the Ningzheng Ridge mountains.
Architectual firm Skidmore, Owings and Merrill designed the building led by Adrian Smith .

Usage of Kruger’s fans:  ventilation and AHU.