Solid-state lighting systems using white light LEDs are quickly becoming a viable solution for interior, ambient lighting in new and existing commercial buildings as they begin to rival the performance of linear and compact fluorescent lighting systems. This is good news for those involved in commercial construction and renovation who are interested in the multiple “green” and related economic benefits of LED lighting. In fact, as the short case study on Virginia Commonwealth University demonstrates, commercial buildings across the country are already specifying LED overhead lighting for retail spaces, universities, corporate offices and housing.

A well-designed LED lighting system for an interior space has multiple benefits compared to incandescent and even compact fluorescent (CFL) systems. With a 50,000-hour lamp life (more than twice that of CFLs), LED systems can easily last more than a decade before requiring replacement – greatly reducing maintenance costs associated with conventional lighting systems. As a result, facility management resources become available to focus on other tasks as the time and labor traditionally dedicated to servicing lamps and ballasts are significantly reduced. 

And the “green” construction benefits are significant. LEDs are inherently more environmentally friendly than CFLs as they do not use mercury or other detrimental, potentially harmful materials. And because LED systems last much longer than fluorescent lighting counterparts, there is less waste (i.e., fluorescent tubes) going to landfills. These environmental benefits can contribute significantly to the sustainability goals for new and existing commercial buildings.

Furthermore, many facilities are able to reduce cooling loads, resulting in substantial savings in air conditioning costs because LEDs generate significantly less heat relative to incandescent and CFL lighting sources, The Department of Energy projects between 2010 and 2030 LED lighting can save 1,488 terawatt hours – representing $120 billion savings in energy at today’s prices.

A final, and often overlooked, advantage of LED lighting is its compatibility with digital lighting controls. As a general rule, LEDs are more “control-friendly” than conventional light sources commonly used today and this is beginning to make a more profound impact on the application and selection of LED systems for mainstream general lighting applications.

Unlike conventional sources, LEDs become more efficient as they dim, and more extensive dimming and control functions actually extend the service life of LEDs. The LEDs light source features a true instant-on capability, and maintains a constant color temperature throughout its entire dimming range. These combined capabilities allow digital controls to substantially leverage LED performance -- lengthening LED life expectancy and improving system efficacy -- making the overall economic equation more attractive.

LEDs are digital light engines that have the ability to interface directly with discrete control devices on-board every light fixture. The result can be an “intelligent” light fixture that has the ability to monitor and respond to its environment, and perform pre-programmed tasks to further conserve input power and reduce lighting maintenance. One example of such a task is executing a constant lumen output over system life to eliminate the waste of over-lighting associated with initial lumens delivered early in a lighting installation.

Additionally, the LED light fixture can be digitally addressable, allowing it to easily network and communicate with other fixtures and like-kind control devices in the same room or throughout a building. Network connections can easily be made using standard CAT5 cabling for true “plug-and-play” convenience. Again, facilitating simpler, more cost-effective control solutions that reduce installation and operating costs for better return on investment.

Unlike conventional light sources, the performance of LED systems significantly improves when they are controlled. This makes LEDs excellent candidates to take advantage of occupancy sensors, dimming, daylight harvesting or facility and campus-wide energy management programs, which further enhance their overall cost-effectiveness.

Given the significant advantages of advanced technology, ambient LED lighting is quickly becoming an innovation of choice among commercial buildings seeking long-term solutions for saving energy, reducing maintenance and operating costs and minimizing their environmental impact.

Virginia Commonwealth University
Virginia Commonwealth University (VCU) is one of the nation’s top – and largest – research universities, with 32,000 students attending two campuses in Richmond, Virginia.   Given its interest in cutting edge research, it comes as no surprise VCU would be an early adopter of advanced LED lighting technologies.

In early 2010, it was determined the Office of Special Services for Students/Testing Center and Division for Health Science Diversity were in need of renovation, and lighting was a key issue. Initially the plan was to simply upgrade lamps and ballasts; however a quick analysis revealed the more cost- and energy-efficient solution was to install new lighting.

VCU challenged the electrical engineers at Hurd & Obenchain, Inc. to get a little creative and investigate the viability of ambient LED lighting as a means to reduce energy use and maintenance costs.

“We chose to evaluate Lithonia Lighting RTLED based on the success we had with the Lithonia Lighting RT5 for office and general lighting,” said Chad Nixon, electrical engineer at Hurd & Obenchain. “Lithonia Lighting RT5 is an exceptional tool that enables us to meet the state’s new IECC watts per square foot requirements while retaining high foot candle levels. Because the RTLED uses the same volumetric technology as the RT5, the RTLED was a natural consideration for us.”

Cramming for the Big Test
Like most projects of this scope, there were several challenges the new LED lighting had to overcome. First, the installation schedule for the renovation was incredibly tight; the fixtures needed to ship almost immediately once the job was awarded. Second, the office space being renovated was very irregular, including two unusually small offices.

“In every way the RTLED met our needs and goals,” said Nixon. “Lithonia Lighting shipped the fixtures on time. The volumetric lighting delivered by the RTLED was a perfect fit for the irregular space. And the product outperformed the competitive fixtures we tested with Hurd & Obenchain’s photometric software.”

Based on the product’s performance – and the immediate needs of the University – more than 100 RTLED fixtures were installed in the fall of 2010. And the feedback on the RTLED since the installation has been nothing short of glowing.

“Prior to this project, I did not have much experience with indoor ambient LED fixtures,” said Don Guthrie, AIA, LEED AP, principal at KOP Architects. “The first time I saw the lighting I was surprised I did not notice a difference between traditional fluorescent lighting and the new LEDs. The light is very soft and evenly distributed.”

The University was equally impressed with the aesthetics of the RTLED fixture and the light quality. “We actually installed LED lighting in the past, but the quality was lacking,” said Carl Beckelheimer, CEM, CRM, VCU Physical Plant energy manager. “However, the Lithonia Lighting RTLED is an attractive fixture and the light quality is exceptional. We are so pleased with the RTLED that it is also being installed in the second phase of the renovation project.”

For more information visit www.lithonia.com/RTLED. You can also follow updates on the Lithonia Lighting LED blog at http://lithonialightingled.com/ or on Twitter at www.twitter.com/lithoniaLED.

About the Author
Dave Ranieri, Acuity Brands Lighting Vice President and General Manager, Lithonia Lighting Commercial Indoor Products, has more than 26 years of experience in the lighting industry. He is responsible for developing new and leading edge fluorescent and LED lighting solutions for commercial interiors. Most recently, he directed LED product development in applications of specification downlighting, general ambient lighting and integration of digital controls.