Sustainable Facility - February 2009 - (Page 11) Lights turn on for cleaning crews. Lights turn on for security patrol. Lights turn on as people arrive at work. Daylighting controls diminish the need for electric lights. Clouds As the sun goe roll in, goes and electric down, lights make electric up for the lights brighte loss of brighten e daylight. even mo more. Lights turn off as people leave work. Tracking a Lighting System’s Power Use This graph shows how lighting power use fluctuates throughout the New York Times building’s 24-hour day. A single Lutron system controls all the lights, turning them on or off, brighter or dimmer as needed. Quantum, it’s using only 0.38 — that’s 70 percent less,” says Glenn Hughes, director of construction for The New York Times Company during the design, installation and commissioning of The New York Times Building. “The energy savings is stunning.” Lutron estimates that the lighting energy efficiency in the Times Company’s 600,000-square-foot office space will generate an annual savings of about $315,000. The environment benefits, too: About 1,250 metric tons of CO2 emissions will be prevented each year — a figure based on the U.S. Department of Energy calculations that for each kilowatt hour saved, the emission of 1.9 lbs. of CO2 is prevented. In The New York Times Building, Quantum provides a wide number of advanced technologies and strategies, including daylight harvesting, light level tuning, scheduling and occupancy sensing. At the heart of the system are the digitally addressable Lutron EcoSystem ballasts, which enhance communication among all the different elements of the lighting controls. Roughly 18,000 such ballasts were installed in the Times Company’s space. This constant, 24/7 communication network — imperceptibly adjusting and reacting to the natural light pouring into the office space, and making thousands of other lighting control decisions throughout each day — allowed the Times Company to achieve its three primary goals for a lighting control system: create an energizing work environment, substantially reduce lighting electricity usage, and easily adapt to the changing needs of the office space. “Our employees are very pleased with the light in our new building,” says David Thurm, senior vice president, operations, The New York Times. “What is also very exciting for us is the ability to learn from the system and to change the system with a few keystrokes. This technology allows us to adapt quickly and flexibly to changes in the way we work.” EFFECTIVE LIGHTING CONTROL The rising demand and costs of energy and electricity are trending upward. In fact, the U.S. Energy Information Administration projects electricity consumption to increase 45 percent by 2030. A typical 50,000square-foot commercial building spends about $45,000 each year on lighting energy. Unfortunately, much of that money is wasted due to ineffective light control. Most buildings today are over-lighted because there is already enough daylight in the space, or lights are set to a higher level than appropriate for the people inside, or spaces are lighted even though they are unoccupied. Whether retrofitting an existing building, or constructing a new one, managing light (both electric light and daylight) is critical to reducing energy costs. Total light control is the ability for a facility to manage and control (i.e., set lights to any level including full-on or off) both electric light and daylight. Electric light can be controlled with a combination of dimming ballasts, daylight sensors, occupancy sensors and wall controls (dimmers or switches) that work together to maintain the correct light level for the various spaces in the building. Daylight can be controlled, as is done in The New York Times Building, using automated window treatments, which are programmed to use the position of the sun and W W W . S U S TA I N A B L E F A C I L I T Y. C O M 11 http://WWW.SUSTAINABLEFACILITY.COM
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