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Lighting Sources

Training manual. Chapter 2. Lighting Sources. Light sources. The development of electrical power well over a century ago revolutionised artificial lighting. It was then that the flame was replaced as the main source of artificial light in favour of electrically powered lighting.

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Lighting Sources

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  1. Training manual Chapter 2 Lighting Sources Lighting concepts – Lighting sources

  2. Light sources The development of electrical power well over a century ago revolutionised artificial lighting. It was then that the flame was replaced as the main source of artificial light in favour of electrically powered lighting. Since that time, the history of electric lighting has been one of continuous development punctuated by a series of major innovations. Lighting concepts – Lighting sources

  3. Light sources Commercial, industrial, and retail facilities use several different light sources. Each lamp type has particular advantages; selecting the appropriate source depends on installation requirements, life-cycle cost, color qualities, dimming capability, and the effect wanted. • Types of lamps that are commonly used: • incandescent • fluorescent • high intensity discharge • mercury vapor • metal halide • high pressure sodium • low pressure sodium • LED lamps Source efficacy Lighting concepts – Lighting sources

  4. Light sources Lighting concepts – Lighting sources

  5. Incandescent Lamps Incandescent lamps are one of the oldest electric lighting technologies available. With efficacies ranging from 6 to 24 lumens per watt, incandescent lamps are the least energy-efficient electric light source and have a relatively short life (750-2500 hours). Light is produced by passing a current through a tungsten filament, causing it to become hot and glow. With use, the tungsten slowly evaporates, eventually causing the filament to break. Emit radiation mainly in the visible region Bulb contains vacuum or gas filling Efficacy: 12 lumen / Watt Color rendering index: 1A Color temperature: 2500 – 2700 K Lamp life <2000 hrs Common incandescent lamp shapes Lighting concepts – Lighting sources

  6. Tungsten-Halogen Lamps The tungsten halogen lamp is another type of incandescent lamp. In a halogen lamp, a small quartz capsule contains the filament and a halogen gas. The small capsule size allows the filament to operate at a higher temperature, which produces light at a higher efficacy than standard incandescents. The halogen gas combines with the evaporated tungsten, redepositing it on the filament. This process extends the life of the filament and keeps the bulb wall from blackening and reducing light output. Advantages: More compact Longer life More and whiter light Efficacy: 18 lumens/Watt Color rendering index: 1A Color temperature: warm Lamp life < 4000 hrs Disadvantages: Cost more Increased IR and UV Handling problems Lighting concepts – Lighting sources

  7. Fluorescent lamps Fluorescent lamps are the most commonly used commercial light source. Their popularity can be attributed to their relatively high efficacy, diffuse light distribution characteristics, and long operating life. Fluorescent lamp construction consists of a glass tube with the following features: filled with an argon or argon-krypton gas and a small amount of mercury coated on the inside with phosphors equipped with an electrode at both ends Features: Halo-phosphate Efficacy – 80 lumens/Watt (HF gear increases this by 10%) Color Rendering Index –2-3 Color Temperature – Any Lamp Life – 7-15,000 hours Different types (T12, T10, T8 and T5) differing in diameter and efficiency Most efficient at ambient temperature of 20-30 oC, Lighting concepts – Lighting sources

  8. Fluorescent lamps Fluorescent lamps provide light by the following process: An electric discharge (current) is maintained between the electrodes through the mercury vapor and inert gas. This current excites the mercury atoms, causing them to emit non-visible ultraviolet (UV)radiation. This UV radiation is converted into visible light by the phosphors lining the tube. Discharge lamps (such as fluorescent) require a ballast to provide correct starting voltage and to regulate the operating current after the lamp has started. Full-size fluorescent lamps are available in several shapes, including straight, U-shaped, and circular configurations Lighting concepts – Lighting sources

  9. Compact Fluorescent lamps Manufactured since the early 1980s, they are a long-lasting, energy-efficient substitute for the incandescent lamp. • The wattages of the compact fluorescents range from 5 to 40 replacing incandescent lamps ranging from 25 to 150 watts and provide energy savings of 60 to 75 percent. • Life expectancy of a compact fluorescent is about 10 times that of a standard incandescent lamp • However, the use of compact fluorescent lamps is very limited in dimming applications. Lighting concepts – Lighting sources

  10. High-Intensity Discharge Lamps (HID) Originally developed for outdoor and industrial applications, HID lamps are also used in office, retail, and other indoor applications There are several advantages to HID sources: relatively long life (5,000 to 24,000+ hrs) relatively high lumen output per watt relatively small in physical size However, the following operating limitations must also be considered. • First, HID lamps require time to warm up, • the average warm-up time is 2 to 6 minutes. • Second, HID lamps have a "restrike" time, meaning a momentary interruption of current or a voltage drop too low to maintain the arc will extinguish the lamp .This process of restriking takes between 5 and 15 minutes • Therefore, good applications of HID lamps are areas where lamps are not switched on and off intermittently. Lighting concepts – Lighting sources

  11. Mercury Vapor discharge lamps Clear mercury vapor lamps, which produce a blue-green light, consist of a mercury-vapor arc tube with tungsten electrodes at both ends. These lamps have the lowest efficacies of the HID family, rapid lumen depreciation, and a low color rendering index. Because of these characteristics, other HID sources have replaced mercury vapor lamps in many applications • Oldest HID lamp • Consists of: arc tube with mercury and argon gas and quartz envelope, third electrode, outer phosphor coated bulb, outer glass envelope • Long life and low initial costs • Very poor efficacy: 30 – 65 lumens/Watt • Color rendering index: 3 • Color temperature: intermediate • Lamp life: 16000 – 24000 hours Lighting concepts – Lighting sources

  12. Metal Halide discharge lamps These lamps are similar to mercury vapor lamps but use metal halide additives inside the arc tube along with the mercury and argon. These additives enable the lamp to produce more visible light per watt with improved color rendition. Wattages range from 32 to 2,000, offering a wide range of indoor and outdoor applications. The efficacy of metal halide lamps ranges from 50 to 115 lumens per watt Works similar to tungsten halogen lamps Largest choice of color, size and rating Better efficacy than other HID lamps: 80 lumen/Watt Require high voltage ignition pulse but some have third electrode for starting Color rendering index: 1A – 2 Color temperature:3000 – 6000 K Lamp life:6000 – 20,000 hours The color may vary from lamp to lamp and may shift over the life of the lamp and during dimming. Lighting concepts – Lighting sources

  13. High Pressure Sodium discharge lamps The high pressure sodium (HPS) lamp is widely used for outdoor and industrial applications. Its higher efficacy makes it a better choice than metal halide for these applications, especially when good color rendering is not a priority. The efficacy of the lamp is very high ( as much as 140 lumens per watt. For example, a 400-watt high pressure sodium lamp produces 50,000 initial lumens Sodium, the major element used, produces the "golden" color that is characteristic of HPS lamps. Used in outdoor and industrial applications Consist of: ballast, high- voltage electronic starter, ceramic arc tube, xenon gas filling, sodium, mercury No starting electrodes High efficacy: 80 – 140 lumen/Watt Color rendering index: 1 - 2 Color temperature: warm Lamp life < 24,000 hrs Lighting concepts – Lighting sources

  14. Low Pressure Sodium discharge lamps LPS lamps are the most efficacious light sources, but they produce the poorest quality light of all the lamp types. Being a monochromatic light source, all colors appear black, white, or shades of gray under an LPS source. LPS lamps are available in wattages ranging from 18-180. LPS lamp use has been generally limited to outdoor applications such as security or street lighting and indoor • Commonly included in the HID family • Highest efficacy: 100 - 200 lumen/Watt • Poorest quality light: colors appear black, white or grey shades • Limited to outdoor applications • Efficacy: Color rendering index: 3 • Color temperature: yellow • Lamp life < 16,000 hours Lighting concepts – Lighting sources

  15. + + Positive layer + - Active area Negative layer - - Circuit board + + + + + + + + - + - + - - - - - - - - LED Lamps • Semiconductor materials: Positive and negative layers • Light generation at direct-voltage • Energy balance: 20% Light 80% Heat • Newest type of energy efficient lamp • Two types: • red-blue-green array • phosphor-coated blue lamp • Emit visible light in a very narrow spectrum and can produce “white light” • Used in exit signs, traffic signals, and the technology is rapidly progressing • Significant energy savings: 82 – 93% • Longest lamp life: 40,000 – 100,000 hours Lighting concepts – Lighting sources

  16. Luminous flux (%) Temperature (°C) LED Lamps White-light results from the mixture of: • Red, green blue • Blue and phosphor-yellow The luminous flux of a LED goes down at higher temperature. An efficient thermomanagement assure an high luminous flux of the luminaire. Lighting concepts – Lighting sources

  17. Why LED? GREEN • Energy Efficient, up to 90% more efficient than traditional lighting sources • Long life span, up to 100,000 hours • Variety of color options • Low operation costs • No UV radiation • No mercury • Instant on, no start-up time • Silent operation • Reduces “Carbon Footprint” Lighting concepts – Lighting sources

  18. Main objectives • Decreasing operational cost • Scalable and available solution • Innovative technology • Security • High quality of work environment • Sustainability, low CO2 emission • No maintenance cost • No heating • Energy efficiency for green certificates BREEAM, LEED Lighting concepts – Lighting sources

  19. MaintenanceFocusing on the highest standard of reliability will minimize repair hassle and allow you to optimize your maintenance regime LED Lamps Energy Identify sustainable lighting solutions to achieve operational cost savings through reduction of energy consumption Energy Aesthetics Maintenance Investment choices Lighting proposals are financially illustrated in a Cost of ownership model to quantify the savings. Aesthetics Ensure the quality of light is not compromised, compliant with norms Investmentchoices Main goals for lighting upgrade Lighting concepts – Lighting sources

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