Despite the fact that lighting may account for 40 percent to 50 percent of a facility’s total energy use, and advanced lighting controls may help reduce that consumption by 50 percent to 75 percent, the majority of today’s lighting system designs are crafted only to meet code.
“The technology is there, but projects rarely allow sufficient funds in the budget for the most appropriate lighting control system,” says Rachel Petro, a lighting designer and associate with RNL in Denver. In contrast, she says, the added cost of advanced control systems is relatively minor in the grand scheme of a new construction project.
When direct energy savings, rebates, and tax credits are entered into the equation, return on investment (ROI) is often less than two years, or in some cases, just one year, says Bob Freshman, marketing manager for Leviton Lighting Management Systems in Tualatin, Ore. To illustrate this, Leviton offers a free downloadable tool, called Dollars & Sensors, for calculating ROI based upon product cost, installation, local power rates, tax credits, and rebates.
Since most codes mandate basic levels of lighting control, occupancy sensors are commonly specified and generally offer savings in the realm of 15 percent and up. A programmable intelligent relay control system can automatically operate a light system based upon time of day. In addition, daylight harvestingwhere lights are automatically dimmed or turned off when the system is cued by natural light levelscan add savings. Daylighting also could help to earn LEED points, says Craig DiLouie, education director for the Lighting Controls Association in Rosslyn, Va. Other possible options include task tuning, defined as automatic dimming for use over designed spaces with excessive electrical lighting for area tasks, and load shedding, where dimming and/or switching kicks in during peak demand periods to ease the load on the grid.
Newer technology offers even more functionality. “As with the rest of the electronics world, smart devices and wireless have made their way into the world of lighting control,” says Brennan Matthews, national sales manager of the energy solutions group for Lutron Electronics Co. “Individual lighting fixtures can now be controlled independently, as opposed to historically being controlled through the line voltage they were wired to.
”New wireless systems can rezone a space using a smart phone or mobile device such as an iPod Touch or iPad. And while digital-based wired systems aren’t as sleek as wireless, they still offer a number of benefits such as simplified wiring, easier networking, and zoning as small as individual fixtures. In addition, notes Debra Fox, a lighting designer at the architectural firm LPA in Irvine, Calif., “the two-way communication system inherent to this digital technology allows for equipment status updates and lamp or ballast maintenance reporting, information which can be used to improve a facility’s maintenance operations, as well as monitor energy consumption.”
Of course, with a plethora of technologies and products on the market, navigating through the sea of offerings can be a little tricky. While ample manufacturer-based literature is available, Avraham Mor, a partner at Lightswitch Architectural, a nationwide design consortium, advises practitioners to seek information from fellow designers and end-users. “I have spent hours upon hours learning about all the different manufacturers’ systems, what they are good for and what they are not,” he says. Fadi Bark, a senior electrical engineer at EYP Architecture & Engineering in Boston, adds, “as technology is constantly changing, designers must keep up with the latest available systems and features so that the best system can be used for the application.”
Finally, the role of commissioning cannot be underestimated. Due to the delicate nature of these systems, if the electronic sensing devices aren’t installed in the correct location with precise orientation, the system will not operate properly, says Adam Sloan, an electrical engineering manager with LPA. As such, Lightswitch’s Mor adds, “after a system is designed, making it do what it’s supposed to do takes time and patience.” Ultimately, a highly efficient lighting controls system will only come to fruition if it’s in the budget, so coming armed with statistics, case studies, and technological information will certainly increase one’s odds of successfully freeing up that elusive funding.
- Barbara Horwitz-Bennett is a frequent contributor to publications in the building and construction industry. She can be reached at bhbennett.com.