Time for a lighting upgrade? You may be torn between LED and induction fixtures. Both offer low maintenance needs, are compatible with a variety of applications, and can secure energy savings. Familiarize yourself with the basics of these technologies to uncover which one will bring your project to light.
Understand the Essentials
Pioneered by Nikola Tesla, induction lighting has been around for over 100 years – plenty of time to earn its “set it and forget it” reputation, says Mark Havira, senior lighting consultant at Efficient Lighting Consultants. Induction lamps rely on ballasts and sealed gas-filled bulbs. Unlike the Edison-style incandescents, induction lamps don’t require a fragile electrode burning inside the bulb to produce light, which allows life expectancy to reach 60,000 hours for retrofit kits or up to 100,000 for the latest manufacturer-provided systems.
“In terms of years, 24/7 use means about 8,700 hours a year,” Havira notes. “In many cases it will be 20 years before you change a lamp on an induction fixture given the right opportunity and environment.”
LED technology is a solid state lighting system, meaning that light is created from electrons moving around within the semiconductor, a piece of solid matter inside the LED. They tend to be more expensive than induction systems, though this is no longer true in all cases, Havira notes: “You have to look at the different wattages on a case-by-case basis and make a determination from there.”
Declining component costs and continuing development are helping to drive down LED prices, Havira continues. The cost of induction systems is unlikely to budge much in either direction because the leaps in innovation have already occurred with induction – there’s not much else to improve on, whereas LED fixtures are still making notable strides.
Most innovation in LED products now focuses on optimizing the entire system rather than individual diodes and other components, adds Gary Trott, vice president of product strategy for Cree. This change has contributed to the decline in cost.
“Sometimes building owners will say ‘Why should I make the change now if the technology continues to improve?’” says Trott. “One reason is that the drops in cost aren’t going to be as large in the future, and the other is that this is the same argument as ‘Why should I buy a computer now if the technology is still improving?’ You buy it now if it makes sense financially for what you’re trying to accomplish.”
Ideal applications for induction systems include high bay areas, wall packs, and “anywhere there are metal halide, pulse start, mercury vapor, or high pressure sodium fixtures,” Havira notes.
That sort of flexibility appealed to the University of California, Santa Cruz, which included induction technology in a portion of its campus-wide lighting retrofit in 2012. The $1.1 million project included a solution for the East Field House Gym’s uneven, insufficient lighting, which stayed around 20 fc.
A design based on 3D lighting simulation led crews to replace 30 metal halide fixtures (all of which were either 175 or 250W) with a dozen 315W induction fixtures, reducing the fixture count by 60% while creating even light distribution and raising the light level to 35 fc.
The wood floor in the gym is easily damaged by heavy equipment like the scissor lifts needed to change out malfunctioning lighting fixtures, making the low-maintenance requirement paramount among the team’s concerns. The existing metal halide fixtures not only consumed a high amount of energy, but they also weren’t conducive to controllability, which in turn worsened the energy consumption problem.
The gym also requires careful attention paid to the fixtures’ safety, as wayward volleyballs can damage the motion and daylight sensors on the ceiling.
“Metal halides don’t turn on and off well at all, but LEDs and induction were fairly equal in that respect,” says Patrick Testoni, energy manager for the campus at UC Santa Cruz. “The induction fix worked well in the gym – when we did modeling, it improved the light distribution in the area and also allowed us to install daylighting and occupancy controls.”