Empire State Building Case Study - March 2019

WHAT IS ENERGY MANAGEMENT WITH RESPECT TO CHILLERS ?

• Currently the industry standard chiller energy management practice is to provide enough cooling to meet the needs of the facility while minimizing chiller run hours.
• This is either achieved manually by experienced operators or automatically by a building automation system or chiller plant manager automation system with operator oversight.
• Neither of these methods addresses the enormous energy savings of increasing chiller performance and operating efficiency.

The Empire State Building, New York, NY. This 1931 vintage building is an American cultural icon and remains the 4th tallest building in the United States today. It is designed in the distinctive Art Deco style and has been named one of the Seven Wonders of the Modern World by the American Society of Civil Engineers. It is ranked number one on the AIA’s List of America’s Favorite Architecture.

The building’s 10,000 ton chilled water plant includes electric and steam driven centrifugal chillers and is located three stories below ground. The plant supplies chilled water to 3 zones ; low, medium and high. Each zone is a primary flow parallel chiller arrangement. Cooling towers are located on the ground floor in the open loading dock area. Mr. Tim Dailey, the Director of Engineering at the Empire State Building, was looking for a way to save more energy in his facility. The Empire State building had already been recognized as a LEED certified building and had incorporated almost every ECM (Energy Conservation Measure) available in the industry. The chilled water plant had VFD’s on all its condenser and chilled water pumps, VFD’s on its cooling towers, VFD’s installed on all its electric driven centrifugal chillers and had a state of the art BMS/CMS operating and controlling the building and optimizing the chilled water plant so it seemed not much was available to further save power at the building’s 10,000 ton chilled water plant. Mr. Dailey still felt that his plant could save additional energy and that’s when he contacted U.S. Chiller Services to have a look at his chilled water plant to see if we could find any opportunity for savings. After a brief inspection of the plant, we were confident we could save at minimum 15% of the plant’s energy and with the plant maintenance being put out for bid, we thought this would be an ideal opportunity to implement retro-commissioning of the plant should we win the bid, which we did.

2017 was used as the baseline year as all ECM’s were fully installed and operational in 2017 and the savings achieved were already confirmed and proven. This was the perfect baseline for us to prove the additional savings we would achieve with our retro/commissioning services which were all performed as part of our service agreement for the chilled water plant. No additional investment was required by the Empire State Building for any savings achieved.

In 2018 we completely retro/recommissioned the chilled water plant paying particular attention to the electric driven York YK centrifugal chillers. We utilized two parameters for savings verification; chiller’s Kw per ton performance and 2017 vs. 2018 utility bills which were weather and occupancy normalized.