New York City has put some greener updates in its tallest skyscraper, the Empire State Building, in the form of refurbished windows that will reduce solar heat gain and decrease the building's energy costs.

These updated windows were installed as part of the Empire State Building retrofit project, which is funded by the Clinton Climate Initiative, the Rocky Mountain Institute, Jones Lang LaSalle and Johnson Controls. The entire project costs $20 million, and aims to cut CO2 emissions by 105,000 metric tons over the next 15 years. It is also expected to decrease energy consumption by 38 percent, and reduce energy costs by $4.4 million per year. 

The project has recently completed the refurbishing of the windows, which will decrease the building's energy costs by $400,000 per year alone. These 6,514 triple-glazed insulated windows panels, which contained 96 percent of the original glass and frames, will also cut solar heat gain by more than 50 percent.

But this project doesn't stop at making the windows more thermally efficient. In addition, the plan is to add insulation to radiators to avoid heat loss, introduce improved lighting, replace air handling units with variable frequency drive fans, improve controllability and efficiency by reusing chiller shells and "replacing the guts," upgrade building control system to improve HVAC operation, upgrade ventilation control system and introduce web-based power systems available to each individual tenant for better management of power usage.

With these updates, the Empire State Building could become LEED (Leadership in Energy and Environmental Design) Gold certified, which means it meets green criteria according to the U.S. Green Building Council. 

The project is expected to be completed by 2013, and upon completion, will become a model for other greener updates throughout New York City as well as other major cities.