text: The building was intended to be energy-efficient compared to its contemporaries. Its water supply consisted entirely of cold water; heat from the building's mechanical systems was recirculated to warm the water and the office spaces. The office spaces were cooled with outside air wherever it was practical. The fluorescent light bars in the ceiling, manufactured by Joseph Loring & Associates, were fitted with glass shields to spread artificial light across a wider area. Even though the rooftop solar collectors were not installed, the other features were intended to reduce energy use by up to 42 percent, compared with a regular office building of the same size. During the summer, the building used a conventional air-conditioning system, offsetting any energy saved by the heat-deflecting facade.
  Citicorp Center was the city's first skyscraper to feature a tuned mass damper. Located within the rooftop mechanical space, the TMD is designed to counteract swaying motions due to wind and reduces wind-related movement by up to fifty percent. The equipment weighs  and includes a concrete block measuring . The block sits on an oil-coated steel plate and has two spring mechanisms, one each to counteract north–south and east–west movement. The equipment cost around $1.5 million to install. By comparison, it would have cost $5 million to reduce the tower's movement by adding  of additional steel.
  Impact