The owners of the Empire State Building have been putting the final touches on a retrofit energy efficiency program that has made the structure the first pre-built commercial building in New York City to achieve LEED Gold certification for prebuilt buildings.
With the retrofitted HVAC system being the largest consumer of energy in the building it was critical to accurately monitor every facet of the system. To crunch the data and optimize system performance, the renovation team selected the Johnson Controls Metasys building management system. But a building management system is only as good as the data it receives.
Major upgrades were done to the HVAC system and chiller plant. A key component was to install BTU energy metering that would be able to accurately meter the new performance of the upgraded chillers, pumps, and chilled water distribution system. Johnson Controls selected FLEXIM ultrasonic clamp-on BTU meters for the task.
There were a couple of reasons for the selection of the FLEXIM meters. Johnson needed metering that could be refit but also obtain accuracy in the very tight piping that is typical of chiller plants. At the Empire State building the space for the chillers was especially small.
Even with the challenges of the shorter pipe runs, the installation of the meters went very smoothly and the FLUXUS BTU meters are now operated for some years and provided accurate and reliable data of the revamped chillers including condenser flow and chilled water tons. The data is sent via BACnet to the Johnson Controls Metasys building management system to monitor and optimize HVAC system throughout the building. As the building efficiencies continue, the FLUXUS BTU meters are also installed to upgrade old or non-existent submetering points throughout the building. FLEXIM's meters have proven reliable and are perfect for retrofit installations because they are nonintrusive and eliminate the need to cut into piping for installation.
In the first year, the original goal of reducing energy usage by 38.4 % that was guaranteed by Johnson Controls was actually exceeded by 5 percent.
In a speech to the Energy Efficiency Forum 2012, Anthony Maltin, the owner of the building, summed up the reason for the team's success:
"So it's important to note we have no compromises here, there are no fewer elevators, there are no reductions - there's no reduction in useful illumination, the building is actually heated and cooled better, more efficiently, and to the greater pleasure of the people in the office than before."