LED vs Halogen lighting; a technical and practical comparison!
For many years the promise of an LED light source as good as the conventional halogen has loomed on the horizon. The challenges of producing a light source with 8-20 times longer life than conventional sources included color, temperature, cost and consistency in application. New technology brought about better efficiency using different materials and processes, resulting in wider uses in applications and reduced costs.
Even though this rapidly advancing field has made great progress, the results have not photometrically (the amount of light cast on the target) been equal to the traditionalhalogen lamp. Professional lighting manufactureres however, have pursued LED lighting for two main reasons. First, the lumen per watt ratio is much better than traditional halogen. In simple terms, this means that you can power an LED lighting system with much less electricity than a traditional system. The comparison chartn below illustrates that a 20 watt 40 degree MR-16 lamp will generate a light pattern 11.6' in diameter with an intensity of 1.95 footcandles. A fixture with an LED array will generate a light pattern with a 10.09' diameter with an intensity of 2.07 footcandles. As you can see, the lighting effect is very similar, but the LED system will do it with 4.5 watts while the halogen system requires 20 watts. Saving 15.5 watts may not seem like much but when you look at the savings in an entire lighting system it becomes more significant. For example, a traditional halogen system might require 260 watts (13 fixtures @ 20 watts) while an LED system would only consume 60 watts. The retail cost of a 300 watt transformer is $317.50 while a 60 watt is $61.25, a significant savings. Additionally, in these "green" times where energy conservation is becoming the standard, yearly operating costs for the LED system is $17.52 as compared to $87.60 for the halogen system.