| Characteristics and Efficiency of Different Light Sources The performance and features of a light source needs to be matched to the lighting task being performed. In order to select the right light source for the job, you should consider important performance variables such as light output (Lumens), efficiency (Lumens/Watt – technically referred to as “efficacy”), lamp life, and color rendering properties measured in terms of the Color Rendering Index (CRI). The CRI is a measure of the degree to which a light source renders colors that are close to true color. For practical purposes it is a number from 0 to 100; the higher the number, the closer to true color. The efficiencies of each type of light source can vary dramatically, so the choice of light source can have a dramatic impact on lighting energy costs. The performance characteristics and efficiencies of common light sources are shown in the table and chart below. | Characteristics of Common Light Sources² | | Light Source | Efficiency | Average Lamp Life | Color | | (Lumens/Watt) | (Hours) | Rendering Index | | Standard Incandescent | 5-20 | 750-1000 | 100 | | Tungsten-Halogen | 15-25 | 2000-4000 | 100 | | Compact Fluorescent | 20-55 | 10,000 | 80 | | Tubular Fluorescent | 60-100 | 15,000-24,000 | 50-90 | | Mercury Vapor | 25-50 | Up to 24,000 | 15-30 | | Metal Halide | 45-100 | 10,000-20,000 | 60-90 | | High Pressure Sodium | 45-110 | Up to 24,000 | 9-70 | | | Cost Comparison of Incandescent and Fluorescent Lamps³ | | Lamp Type | Energy Costs | First Cost | Maintenance Costs | | Incandescent | Much Higher | Lower | Higher | | Fluorescent | Much Lower | Higher | Lower | |  The Comparison of different Lamp Sources | LAMP COMPARISON CHART * | | WATTS | LUMENS | LUMEN / WATT | min.START TEMP. | STARTUP TIME | RESTRIKE TIME | AVG. LIFETIME | COLOR TEMP. | | | INCANDESCENT | | 40w | 480 | 12 | -40° | instant | instant | 1000 h | 2700k | | 60w | 890 | 15 | -40° | instant | instant | 1000 h | 2700k | | 75w | 1,200 | 16 | -40° | instant | instant | 1000 h | 2700k | | 100w | 1,700 | 17 | -40° | instant | instant | 1000 h | 2700k | | 150w | 2,550 | 17 | -40° | instant | instant | 1000 h | 2700k | | TUNGSTEN HALOGEN | | 35w | 900 | 26 | -40° | instant | instant | 3500 h | 3000k | | 50w | 1300 | 26 | -40° | instant | instant | 3500 h | 3000k | | 65w | 1,700 | 26 | -40° | instant | instant | 3500 h | 3000k | | LED (white) | | 0.03-5w | | 18-115 | -40° | instant | instant | 50,000 - 100,000 h | 2700-10,000k | | COMPACT FLUORESCENT | | PL13w | 1,050 | 81 | -20° | .5 to 5 sec. | 1 sec. | 10,000 h | 2700-6500k | | QUAD 28w | 1,500 | 57 | 0° | .5 to 5 sec. | 1 sec. | 10,000 h | 2700-6500k | | CF26w | 1,800 | 69 | -20° | .5 to 5 sec. | 1 sec. | 10,000 h | 2700-6500k | | CF32w | 2,400 | 75 | -20° | .5 to 5 sec. | 1 sec. | 10,000 h | 2700-6500k | | CF42w | 3,200 | 76 | -20° | .5 to 5 sec. | 1 sec. | 10,000 h | 2700-6500k | | METAL HALIDE | | 50w | 3,500 | 70 | -20° | 2-5 min. | 10-20 min. | 5,000 h | 4000k | | 70w | 5,000 | 71 | -20° | 2-5 min. | 10-20 min. | 7,500 h | 4000k | | 100w | 8,500 | 85 | -20° | 2-5 min. | 10-20 min. | 15,000 h | 4000k | | 150w | 13,000 | 87 | -20° | 2-5 min. | 10-20 min. | 15,000 h | 4000k | | 175w | 14,000 | 80 | -20° | 2-5 min. | 10-20 min. | 10,000 h | 4000k | | 250w | 20,500 | 82 | -20° | 2-5 min. | 10-20 min. | 10,000 h | 4000k | | LOW PRESSURE SODIUM | | 18w | 1,800 | 100 | -20° | 7-10 min. | 3-12 sec. | 18,000 h | 1700k | | 35w | 4,800 | 137 | -20° | 7-10 min. | 3-12 sec. | 18,000 h | 1700k | | 55w | 7,800 | 142 | -20° | 7-10 min. | 3-12 sec. | 16,000 h | 1700k | | HIGH PRESSURE SODIUM | | 50w | 4,000 | 80 | -40° | 3-4 min. | 1 min. | 24,000 h | 2200k | | 70w | 6,300 | 90 | -40° | 3-4 min. | 1 min. | 24,000 h | 2200k | | 100w | 9,500 | 95 | -40° | 3-4 min. | 1 min. | 24,000 h | 2200k | | 150w | 16,000 | 107 | -40° | 3-4 min. | 1 min. | 24,000 h | 2200k | | 250w | 30,000 | 120 | -40° | 3-4 min. | 1 min. | 24,000 h | 2200k | | MERCURY VAPOR | | 50w | 1,580 | 32 | -30° | 5-7 min. | 3-6 min. | 24,000 h | 3200-7000k | | 75w | 2,800 | 37 | -30° | 5-7 min. | 3-6 min. | 24,000 h | 3200-7000k | | 100w | 4,100 | 41 | -30° | 5-7 min. | 3-6 min. | 24,000 h | 3200-7000k | | 175w | 7,900 | 45 | -30° | 5-7 min. | 3-6 min. | 24,000 h | 3200-7000k | | 250w | 12,100 | 48 | -30° | 5-7 min. | 3-6 min. | 24,000 h | 3200-7000k | | INDUCTION LAMP | | 55w | 3,500 | 64 | -40° | .5 to 5 sec. | .5 to 1 sec. | 100,000 h | 3000k | | 85w | 6,000 | 70 | -40° | .5 to 5 sec. | .5 to 1 sec. | 100,000 h | 3000k | | 165w | 12,000 | 72 | -40° | .5 to 5 sec. | .5 to 1 sec. | 100,000 h | 3000k | | |
