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LED LIGHTING FREQUENTLY ASKED QUESTIONS

Why should I use LED lighting instead of fluorescent?

  • LED light is roughly twice as energy efficient as fluorescent, as measured in lumens per watt.
  • LED lights are dimmable, and become more efficient when dimmed.
  • LEDs always start instantly, but fluorescents are slow to start and to reach full brightness in cold temperatures.
  • LEDs contain no mercury so they will be safe to dispose of when they eventually need replacement.
  • LEDs are not made with glass, so glass breakage is not an issue.
  • LEDs produce only about half of the waste heat of fluorescents, so they lower air-conditioning costs.

How efficient is LED lighting?
Efficiency of all light sources depends on several variables, but typically LEDs are six times more efficient than incandescent bulbs and twice as efficient as fluorescent tubes.

What is “Color temperature”?
Both LED and fluorescent lights are available in various colors. Older fluorescent lamps are typically sold as “warm white” or “cool white”. Today these colors are usually expressed numerically, “warm white” is about 2700 K and “cool white” is about 4000K. Incandescent light bulbs are typically a warm 2500K.

What is CRI?
CRI stands for “Color Rendering Index”. Natural sunlight has a “perfect” CRI of 100. A low CRI means the light is not the same color as sunlight.

How long will LED lights last?
LED “life” is usually measured in time to degrade to 80% of original brightness (L80). This time is often in the range of 50,000 hours (over 5 years). Continued use beyond 50,000 hours usually brings gradual loss of brightness, not outright failure. Temperature has a strong effect on life. Cooler is better, so good fixture design involves thermal management.