Solid-state lighting systems using light-emitting diode (LED) bulbs are a viable solution for interior ambient lighting, as they now exceed the performance of linear and compact fluorescent light (CFL) systems.
This is good news for facility managers who are interested in the multitude of green and economic benefits of using digital lighting technology.
In fact, commercial facilities of all sorts, including schools and universities, retailers and office buildings, are installing LED lighting and reaping the benefits.
A well-designed LED lighting system for an interior space has many benefits compared to incandescent and even linear fluorescent systems.
Reducing maintenance time and costs, energy costs, downsizing a facility''s environmental footprint and integrating LEDs with controls are the four key benefits.
1. Time savings
With a 50,000-hour lamp life — more than twice that of fluorescent bulbs — LED systems can easily last more than a decade before requiring replacement, greatly reducing maintenance costs associated with conventional lighting systems.
As the time and labor traditionally dedicated to servicing lamps and ballasts are significantly reduced, facility management resources become available to focus on other tasks.
San Diego State University (SDSU) is one recent example of how maintenance staff can benefit from LED lighting.
The university recently converted a 5,800-square-foot gymnasium into a 215-person lecture hall.
"If the new LED lighting system is on five days a week for eight hours a day, the lights will last 15 years," said Dr. James Frazee, director of instructional technology for SDSU. "This frees up the maintenance staff to focus on more important jobs."
2. Increased sustainability
LEDs are inherently more environmentally friendly than conventional light sources, 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 going to landfills.
These environmental benefits can contribute significantly to the sustainability goals for new and existing facilities.
3. Reduced cooling loads
Because LEDs generate significantly less heat relative to incandescent and fluorescent lighting sources, many buildings are able to reduce cooling loads, yielding substantial savings in air conditioning costs.
The U.S. Department of Energy (DOE) projects that, between 2010 and 2030, LED lighting will save 1,488 terawatt hours — representing a $120 billion savings in energy at today''s prices.
4. Added control
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-wide and campus-wide energy management programs, which further enhance their overall cost effectiveness.
This synergistic combination is making a profound impact on the application and selection of LED systems for mainstream general lighting applications.
As a general rule, LEDs are extremely "control-friendly" relative to conventional light sources.
Unlike conventional sources, LEDs become more efficient as they dim.
Also, more extensive dimming and lighting control functions actually extend the service life of LEDs.
Beyond capability, the inherent compatibility of LEDs with digital lighting controls may ultimately hold the greatest potential for economic benefit.
LEDs are digital light engines that can interface directly with discrete control devices onboard every light fixture.
The result is an "intelligent" light fixture that has the ability to monitor and respond to its environment and perform preprogrammed tasks to further conserve input power and reduce lighting maintenance.
One example of such a task is delivering 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 is digitally addressable, allowing it to easily network and communicate with other fixtures and control devices in the same room or throughout a building.
Another real world example of how LED lighting and controls can maximize the benefits of LEDs is the Minneapolis Public Housing Authority (MPHA).
The MPHA was renovating a 25-story building, which included hallways, stairwells and community rooms that were illuminated 24 hours a day, 365 days a year — despite being unoccupied for significant periods of time.
As a way to reduce energy use and only have the common area lit when needed, the MPHA installed ambient LED lighting and LED down lighting with occupancy sensors.
"The lighting fixtures paired with occupancy sensors allowed us to significantly reduce our energy use," said John Plifka, MPHA manager of facilities and development. "Specifically, our stairwell lighting system is used only when needed, which currently adds up to about three hours a day. The LED lighting and the occupancy sensors together helped us reduce our energy use by 90 percent in the stairwells, and the LED fixtures are expected to last 45 years. Throughout the entire building, the LED lighting system and the controls reduced energy consumption by more than 77 percent, reduced carbon dioxide emissions by 76 percent and reduced maintenance costs by 58 percent."
Given the significant advantages of advanced digital lighting technologies, ambient LED lighting is quickly becoming the innovation of choice for commercial building engineers and facility managers across North America seeking long-term sustainable solutions that save energy, reduce maintenance and operating costs and minimize their environmental impact.
Dave Ranieri is the vice president and general manager of Lithonia Lighting''s Commercial Indoor Business unit. He has more than 26 years of experience in the lighting industry and has led LED product development for numerous indoor applications. Most recently, Ranieri has been involved in commercializing the first indoor ambient LED lighting product series, the Lithonia Lighting RTLED, TLED, ACLED and VTLED.