4 FM quick reads on LED
1. Smart Uses for LEDs
"LEDs are not magical." That's one quote from a recent tradeshow in Chicago for lighting specifiers. While the main conversation was not aimed squarely at facility managers, there were a few tips and food for thought. If there was one take-away for facility managers it was to consider the strengths and weaknesses of a lighting source and match it appropriately with the lighting application.
Here are two misconceptions lighting designers have experienced from their clients (you!) in regards to using LEDs in commercial applications:
- LEDs are great, everywhere! When a small project with a focused application for LEDs has great success, facility managers can be tempted to want to deploy LEDs everywhere. But their attributes — chiefly their highly directional nature — and operating characteristics, make them unsuitable for a wholesale deployment without careful consideration for the needs and challenges of the application.
- LEDs last forever and are maintenance-free! While it is true that quality LEDs from proven manufacturers have shown very long lives and high-reliability, the LED module is just one component affecting maintenance. As one presenter said, there are still birds in the world, there is still dust. Lenses can still discolor with age and other components in the luminaire can fail.
Other challenges posed by LEDs are brightness and glare problems, but lighting specifiers report that facility managers are so taken with LED technology that they're willing to be more lenient on these points than perhaps they should be. Color matching is another hurdle with LEDs, as color temperatures can vary between manufacturers, or even between batches of the same product. The industry is responding to this by developing color-tunable LEDs and also seeking to develop new standards to describe the quality of the LED light output as perceived by the human eye.
LED technology has evolved to the point where it is being deployed in a broad range of applications. Some of the best ways to deploy the technology still seem to be in highly-directional applications, as well as to highlight architectural features, where the lack of radiated heat is a benefit, in very tight spaces, or on bridges or other areas where vibration is present, as LEDs are less affected by this than other light sources.
For more pros and cons of LEDs, check out this.
Consider exterior lighting upgrades as savings source
Today's tip is to look at your exterior lighting as a source of savings. Turning off exterior lighting loads for institutional and commercial facilities is the most effective way to save energy, but it might not address the lighting needs of the general population. People need some form of exterior illumination to feel safer and more secure. Beyond functional lighting, people also need lighting that enhances the nighttime atmosphere to encourage activity and make spaces feel inviting.
Every year, building codes and green building programs require that facilities further reduce energy consumption. Advances in technology have reduced loads for interior building lighting, but only recently have manufacturers considered extending these energy savings to outside.
Because organizations use exterior lighting to provide security and aesthetic appeal, it is no surprise that managers hesitate to turn off outside lights. But the lighting system for a parking lot designed in 1970 — or even 2000 — probably is outdated by today's standards.
Replacing the key components of a high-pressure-sodium fixture with LED lamps might reduce energy consumption and deliver a reasonable payback of two-four years — or, with rebates, instantaneous payback. Managers should be sure to specify LED sources from reputable, established manufacturers who have controlled binning standards, proven heat sinks and fixtures specifically tested and designed for their LEDs.
The most efficient LEDs are cooler white. In exterior applications, cool blue color temperatures also can result in reduced allowable lighting levels. But at least in the United States, cooler light — usually anything greater than 4,100 Kelvin (K) often is perceived as uncomfortable, sterile, and institutional. Building facades appear more inviting when illuminated with a warmer light — 3,000-3,500 K — that also has a high color rendering index (CRI). A CRI greater than 80 makes the finishes of materials and objects appear more true and rich.
Managers also should take care should to select a lamp that is compatible with the project's geographic location and the connected controls. Fluorescent lamps do not like low temperatures. Dimming ballasts also generally are not fond of temperatures below 50 degrees. Induction lamps are more compatible in cold environments, tend to produce less glare, and have one of the longest life spans. But they are not dimmable, and their distribution patterns can be difficult to control through fixture optics.