Lights tonight:
ESB Signature Color
full schedule

Projects in Detail

The recommended package of 8 projects saves nearly 40% of the energy at the Empire State Building, but almost all the changes are unnoticeable from the outside and by visitors to the 86th floor Observatory.

A tenant space with natural afternoon lighting

The sustainable transformation of the Empire State Building has happened inconspicuously – and the huge energy savings come from the interaction between the multiple retrofits. Tenants will find opportunities for enhanced, more comfortable office spaces, and engineers have the most advanced tools to monitor how energy is being used throughout the building.


Read descriptions of each project by clicking the slide links to the right.

Radiative Barrier

This project involved the installation of more than 6,000 insulated reflective barriers behind radiator units located on the perimeter of the building. In addition, the radiators were cleaned and the thermostats were repositioned to the front side of the radiator.


Tenant Demand Control Ventilation

This project involved the installation of CO2 sensors for control of outside air introduction to Chiller Water Air Handling and DX Air Handling Units . One return air CO2 sensor has been installed per unit in addition to having removed the existing outside air damper and replacing it with a new control damper.

Tenant Daylighting, Lighting, and Plugs

This measure involved reducing lighting power density in tenant spaces using ambient, direct/indirect, and task lighting, installing dimmable ballasts and photosensors for perimeter spaces that can operate with electric lights off or dimmed depending on daylight availability, and providing occupants with a plug load occupancy sensor for their personal workstation.

It is not expected that the Empire State Building provide the capital to ensure these measures are implemented, rather it is expected that the Empire State Building provide tenants with the examples (via pre-builts), the data (the team analysis), and the tools (the eQUEST model) to help them understand the cost savings of these measures over the term of their lease. ESB will benefit from tenant compliance with these recommendations as it will result in lower overall cooling demand and higher sustainability ratings for the building. Tenants will benefit from reduced utility costs and higher quality, more productive spaces.

Balance of Direct Digital Controls (DDC)

The balance of DDC project involved upgrading the control systems at the Empire State Building. The project design and layout was based on using Johnson Controls Metasys Extended Architecture BACnet controllers and includes Ethernet and BACnet risers with all necessary devices and equipment, ADX server/workstation, printer, software, and web access capability.

This measure includes control upgrades for the following building systems:

  • Refrigeration Plant Building Management System;
  • Condenser Water System Upgrades;
  • Chiller Water Air Handling;
  • DX Air Handling Units;
  • Exhaust Fans;
  • Stand Alone Chiller Monitoring;
  • Misc. Room Temperature Sensors; and
  • Electrical Service Monitoring.

Chiller Plant Retrofit

The chiller plant retrofit project included the retrofit of four industrial electric chillers (one low zone unit, two mid zone units, and one high zone unit) in addition to upgrades to controls, variable speed drives, and primary loop bypasses.

All existing pumps and steam chillers remain. For the low zone chiller, the retrofit involved the installation of: a new chiller mounted variable speed drive, a new VSD-rated compressor motor, a new IEEE Filter in VFD to reduce harmonic distortion, and a new Optiview Graphic Control Panel with latest software revision. For all other chillers, the retrofit involved the installation of: new drivelines, new evaporator and condenser water tubes, new Optiview Graphic Control Panels with the latest software revision, chiller water bypasses with two-way disk type valves, new piping in place of backwash reversing valves, new automatic isolation valves on the CHW supplies to each electric chillers, and temperature and pressure gauges on all supply and return lines. In addition, R-500 refrigerant were removed (per EPA guidelines) and replaced with R134A refrigerant. The existing steam chillers remained. All electric chillers, CW and CHW pumps, pump VFDs, and zone by-pass valves are controlled by the Metasys control system.

VAV Air Handling Units

Empire State Building has replaced all constant volume air handlers with identical units. The team recommended a new air handling layout (two floor-mounted units per floor instead of four ceiling-hung units) as well as the use of variable air volume units instead of existing constant volume units.

This recommendation resulted in little additional capital cost while reducing maintenance costs (as the quantity of air handlers will be reduced and they will be floor-, as opposed to, ceiling-mounted) and improving comfort conditions for tenants (reduced noise and increased thermal accuracy and control).

Building Windows

This project involved upgrading the existing insulated glass (IG) within the Empire State Building's approximately 6,500 double-hung windows to include suspended coated film and gas fill.

This "re-manufacturing" of the IG units took place within the Empire State Building. IG units were removed, delivered to a production area, and picked up for reinstallation. Alpenglass TC88 or SC75 were used as the suspended film according to the orientation. A mix of krypton/argon gas was used between the glass and suspended film. This project improved the thermal resistance of the glass from R-2 to R-6 and cut the heat gain by more than half, in addition to allowing for the recycling of all existing glass.

Tenant Energy Management

This project allows for the independent metering of a greater number of tenants in the Empire State Building. Tenants have access to online energy and benchmarking information as well as sustainability tips and updates.

A EnNET/AEM platform will be provided for collecting 15-minute meter data and creating a normalized database that can be used to support Time Series profiling, reporting to ISO, and integration in the future with property management software for creating a bill based on current meter read. In addition, the AEM application will be commissioned and web pages will be created to properly display metering data, Time Series Analysis, real-time metering information, and to create notifications based on usage parameters.