"lumens" - 1 õppematerjal

Energy - põhjalik referaat energiast

Lighting is essential to a modern society. Lights have revolutionized the way we live, work, and play. Picture 2.2. How energy is used in homes (2005) 5 Most homes still use the traditional incandescent bulbs invented by Thomas Edison. These bulbs convert only about ten percent of the electricity they use to produce light, the other 90 percent is converted into heat. In 1879, the average bulb produced only 14 lumens per watt, compared to about 17 lumens per watt today. By adding halogen gases, the efficiency can be increased to 20 lumens per watt. Compact fluorescent bulbs, or "CFLs", have made inroads into home lighting systems in the last few years. These bulbs last much longer and use much less energy, producing significant savings over the life of the bulb. Appliances such as refrigerators, washing machines and dryers are also more energy efficient than they used to be