2009-04-01 P & R Packet - Laserfiche WebLink

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LED lamps vs. Other Lamps Traditional lamps are radial light sources and are subject to fixture losses of 40 to 60 percent. When light exits a lamp, much of it is moving away from the target. As the light reflects off the insides of the fixture, much of it is lost and never makes it to the area that needs lighting. LEOS emit light only in one direction, in a focused cone. It may produce half as much initially but the amount of light that makes it to its intended area may be more than a traditional lamp with twice the initial lumen rating. A rating of 5000 lumens results in useful 'out of the fixture' rating around 2000 - 3000 lumens. Sol LED light sources are directed light sources and are rated by their out of fixture lumens, all of the fixture losses are all ready accounted for. LED lights used in Sol's solar applications have a I OO,OOO-hour life and have minimal lumen depreciation over the life of the lamp. This long life translates to reduced maintenance costs, greater reliability, and a brighter lamp. LEOs do not contain mercury, a disposal hazard. Sol LEOS will withstand shocks greater than 50- G. There is nothing fragile in an LED. LED lamps vs. Fluorescent (CFL) Solar lights in the past have used compact fluorescent lamps (CFL). The fluorescent tube contains a vapor that gives off ultraviolet light when ionized. The ultraviolet light makes particles that coat the inside of the tube, and these particles glow or fluoresce. The life of a CFL is only 8-10,000 hours or about 2.S years. In addition, the lumen output of a CFL will depreciate rapidly, making the lamp permanently dimmer over the life of the lamp. LEOS are the better choice, as it requires less maintenance and provides a long life. When a CFL starts to burn out, it creates dark spots, which reduces the area illuminated. CFL lamps contain mercury- a disposal hazard. LED lamps vs. High Pressure Sodium (HPS) IHPS lamps are more efficient than metal halide but are not a good choice when true color is critical. The light output is an orange-gold color. HPS lamps are also not very efficient at low wattages, unlike solar powered applications, which are more efficient. The life rating of HPS lamp is another consideration. The average life for an HPS is 25,000 hours, approximately one quarter of the life on an LED. When the HPS lamps fail, it fails completely, whereas LEOS only get dimmer. The I OO,OOO-hour life of a LED is the point where the lamp has lost 30% of its lumen maintenance. This long life translates to reduced maintenance costs, greater reliability, and a brighter lamp. Light color is measured using a color index (CRI) of I to I DO, with 100 representing sunlight. The IESNA guideline recommends a CRI of 50 or higher. LEOS produce a white light with an excellent CRI, which means you need less lumens to see color - how well you can see the color of a fleeing suspect's clothes or hair. 12