Kuegler Associates: Consulting Engineers - Designed Right = Built Right

LED lights have rapidly grown in popularity and over the past few years they have improved considerably in terms of light quality and efficiency. Today, they have many of the same favorable qualities of incandescent lights – a warmer glow, faster warm-up – without the drawbacks.

What are LEDs?
LED is an abbreviation of light-emitting diodes. They are semiconductor devices and a type of solid state lighting that produces visible light when an electrical current is passed through it. They are exponentially more efficient than traditional incandescent bulbs because incandescents use electricity to heat up a metal filament that glows white, creating light, but wasting 90 percent of their energy as heat. Other LED benefits include no UV or infrared emission, relatively cool running performance, and the ability to withstand vibration because they have no filament to break.

However, early LEDs took a relatively long time to warm up, which could be frustrating for users entering a dark room. Once fully on, they cast a pure white light that some people found “cold” and unappealing compared to the warm, soft, slightly yellowish glow of the old incandescent bulbs.

Improvements in LED lighting technology have dramatically shortened the turn-on time — now virtually instant-on — and created a warmer, more appealing cast to the glow. Today’s LEDs also experience no detrimental effects from rapid cycling on and off and can be used in motion lights and photocells.

One characteristic that eluded LED technology until recently was the ability to dim. Today, a variety of dimmable LED lights are available for consumer and commercial use. Dimmable LED features include:

  • High-powered versions
  • Wide selection of shapes and styles, including “A” shapes, PARs, MRs, globes, and chandeliers
  • 30,000-hour lifetimes, or up to 27 years
  • RoHS compliance
  • Mercury-free
  • Instant-on

However, it’s important to note that dimmable LED lights can operate noticeably differently than incandescents. Since LEDs consume such a low wattage, many types of dimmers do not function with LEDs in the same way that they do with high wattage load incandescents.

When dimming LEDs you may notice:

  • Smaller dimming range (Typically 70-90 percent dimmable compared to 100 percent with incandescent)
  • LED bulbs may not shut off at lowest dim setting — the dimmer can be fooled into thinking the bulb is completely off because of the low wattage LEDs use
  • Dimming systems based on X10 or Power Line Carrier (PLC) control technology may cause LEDs to flicker when modules are communicating due to the small fluctuations in power on the line
  • Current LEDs do not shift color when dimmed – unlike an incandescent bulb, they will not offer a soft fiery glow when dimmed

Still, there’s no denying the many benefits of LEDs. Their long-life, energy-efficiency, quality light, and versatility make them a favorite for many residential and commercial uses.