The Empire State Building on Wednesday announced the completion of a building-wide window refurbishment.
The initiative is one of eight measures implemented at the landmark as part of an innovative energy retrofit project announced in April 2009 with President Bill Clinton and New York City Mayor Michael Bloomberg.
The building’s 6,514 windows were refurbished through a groundbreaking process that reused 96% of the existing glass and frames. The initiative alone will directly reduce building energy costs by more than $400,000 annually.
Johnson Controls (NYSE: JCI), the organization responsible for implementing the retrofit program, contracted Serious Materials to take on the project. In a novel process, Serious Materials reused the existing materials to create super-insulating glass units (IGUs) in a dedicated processing center located within the building. Thousands of windows at the building were seamlessly retrofitted and replaced overnight over the course of seven months, three months ahead of schedule, without any disturbance to tenants.
The super-insulated units are four times more thermally efficient compared to older dual pane windows and are expected to reduce solar heat gain by more than 50%. The cost to refurbish each window is estimated at $700 compared to approximately $2,500 to replace with new, comparable windows.
"The Empire State Building began an innovative retrofit program in 2009 to bring the world’s most iconic building to the forefront of energy efficiency. This process serves as a replicable model for commercial buildings globally," said Anthony E. Malkin, of owner, Empire State Building Company. He added, "The window retrofit is a key milestone in the Empire State Building project, already proving that buildings can be retrofitted efficiently and economically while providing rapid payback."
Upon completion of the sustainability program, the Empire State Building is expected to reduce total energy usage by more than 38%, energy costs by $4.4 million annually, and carbon emissions by 105,000 metric tons over the next 15 years.
Other elements of the energy retrofit include:
- Radiator Insulation Retrofit: Added insulation behind radiators to reduce heat loss and more efficiently heat the building perimeter.
- Tenant Lighting, Daylighting and Plug Upgrades: Introduction of improved lighting designs, daylighting controls, and plug load occupancy sensors in common areas and tenant spaces to reduce electricity costs and cooling loads.
- Air Handler Replacements: Replacement of air handling units with variable frequency drive fans to allow increased energy efficiency in operation while improving comfort for individual tenants.
- Chiller Plant Retrofit: Reuse of existing chiller shells while removing and replacing "guts" to improve chiller efficiency and controllability, including the introduction of variable frequency drives.
- Whole-Building Control System Upgrade: Upgrade of existing building control system to optimize HVAC operation as well as provide more detailed sub-metering information.
- Ventilation Control Upgrade: Introduction of demand control ventilation in occupied spaces to improve air quality and reduce energy required to condition outside air.
- Tenant Energy Management Systems: Introduction of individualized, web-based power usage systems for each tenant to allow more efficient management of power usage.
The window retrofit project, along with other details of the sustainability initiative, are showcased in the Empire State Building’s recently unveiled $2.0 million, multi-media sustainability exhibit in its world famous Observatories’ second floor visitors center. The exhibit is open seven days a week from 8 a.m. to 2 a.m.