homeaboutpartnersnewsdownloads principlesin depthapplicationsteaching resourceslearning resourcesprinciples Artificial Lighting There are plentiful types of lamps in the market. They are different from each other by their principles of light production which influence their main characteristics (color temperature of the source, luminous flux, …) Lamps IncandescentClassic incandescent lamp Halogen incandescent lamp Gas dischargeSodiumHPHigh pressure sodium lamp BPLow pressure sodium lamp MercuryBPFluorescenttube with magnetic ballast tube with electronic ballast Compact fluorescent lamp (CFL) Induction lamp HP Metal halide Quartz burner Ceramic burner LED * In red : lamps for interior artificial lighting A lamp will be chosen according to its destination (dwellings, offices, refrigerated room, bathroom,…) and its usage (general lighting, backup lighting, ambient lighting, …) and by analyzing its main characteristics : Photometric (flux, spectrum, output,…) Electric (voltage, power, base) Geometric (dimensions, positions, …) Ecologic (recycling, …) Economic (life time, cost, ….) Sources : Architecture et Climat

homeaboutpartnersnewsdownloads principlesin depthapplicationsteaching resourceslearning resourcesin depth Artificial Lighting Lamps Summary table of important characteristics in choosing a lamp Type Power (W) Luminous flux (lm) Luminous efficacity (without ballast) (lm/W) IRC CCT (K) Durée de vie util (h)e Durée de vie moyenne (h) Prix brut (c€/lm) Incandescent 25 to to to to Halogen 40 to to to to 0.2 Tube fluorescent 14 to to to to to to to to CFL 5 to to to to to to 0.2 LED 55 to to to to 20 Metalhalide 35 to to to 9665 to to to to to 0.1 Sodium high pressure 35 to to to (85)2000 to to ,425 to 0.1 Mercury high pressure 50 to to to 5833 to to to to 0.1 Sodium low pressure 35 to to to to 0.2 Sources :

homeaboutpartnersnewsdownloads principlesin depthapplicationsteaching resourceslearning resourcesin depth Artificial Lighting Lamps 1. Mode of production 1.1. Incandescent : In incandescent lamps, light is produced by heating a thin tungsten filament with an electric current. Tungsten filament is in a vacuum globe or under an atmosphere containing a specific gas (halogen lamps). In the vacuum globe, the filament heat and lose matter by sublimation. This metal vapor condenses and settles on the globe surface. The filament becomes thinner until the filament broke. The life time of a classical lamp is around 1000 hours. When a halogen gas is present inside the globe instead the vacuum, a part of the tungsten vapor return on the tungsten filament. With this, the life time of the halogen lamp is around 2000 hours. An improvement of this technology is the Infra-Red coating (IRC) halogen. These lamps have a specific recovery in the bulb that redirects the infrared radiation on the tungsten filament to heat it with less energy. The efficacy of these halogen lamps is higher than the classic halogen (20 to 30 %) Sources : Benoit Roisin, Arnaud Deneyer, Magali Bodart, Peter D’Herdt, Bertrand Deroisy, Guide pratique et technique à l’éclairage des logements, Architecture et Climat,UCL, Division Energie et Climat,CSTC, available soon

homeaboutpartnersnewsdownloads principlesin depthapplicationsteaching resourceslearning resourcesin depth Artificial Lighting Lamps 1.2. Gaz discharge/fluorescent lamp Gas discharge lamps produce light by sending an electric discharge in an ionized gas. Electrons excited inside the lamps emit photon and an ultraviolet radiation is produced and then converted in visible light by the coating inside the lamp. A starter and a ballast are necessary to initiate the discharge and to stabilize the current. Ballast : this device is a kind of resistance, used in the system to limit the current. And provide the high voltage required for ignition of the tube. The ballast can be electromagnetic or electronic. -For the electromagnetic ballast, it can take the simple form of series resistance and it has to be used with a starter. -For the electronic ballast, the system (ballast+starter) is replaced by a semi-conductor circuit. Starter : this device is an electric dipole which behaves like a switch. It is placed in parallel in the circuit. Sources : Architecture et Climat

homeaboutpartnersnewsdownloads principlesin depthapplicationsteaching resourceslearning resourcesin depth Artificial Lighting Lamps 1.3. Light-emitted diode A light-emitted diode (LED) is a semiconductor light source able to produce light with the passage of an electrical current. The LED is a semiconductor composed of a junction of two materials one of which has an excess of electrons and the other a lack of electrons. When this junction is subjected to a voltage difference, the excess electrons will pass through the area in need and recombine them. This recombination generates monochromatic radiation. The color of light produced depends on the material used to achieve doping (red-orange-green-yellow-blue). Sources : Architecture et Climat

homeaboutpartnersnewsdownloads principlesin depthapplicationsteaching resourceslearning resourcesin depth Artificial Lighting Lamps 2. Main caracteristic 2.1. electrical caracteristic Voltage : potential difference between two terminals Power : the unit of power is in Watt and influence the electrical consumption. Base : basis of a light bulb used in conjunction with the sleeve Dimming : is the possibility to decrease the intensity of the luminous flux of the lamp. By this way, you can consider the natural ligthing. The life time depends of the type of lamps Starting time : some lamps take a moment to attempt the 100% flux photometric caracteristic The luminous flux (Ф - lm) is the quantity of light emitted by the source in all direction by unit of time. The Efficacity (η – lm/W) is the quotient of luminous flux(  ) by the electric power(W) and should be as large as possible. Sources : Architecture et Climat

homeaboutpartnersnewsdownloads principlesin depthapplicationsteaching resourceslearning resourcesin depth Artificial Lighting Lamps The spectrum = spectral distribution curve = how the radiated energy is distributed. It can be continue, discontinue or mixed. The spectrum of a ligth source influences its color temperature and the color rendering. -The correlated color temperature (CCT - K) of a light source is the temperature at which a black body should be heat to radiate light a similar hue of the light source. A low CCT means a warm ambiance (red color) and a high CCT means a cold ambaince (blue). The CCT will be chosen according to the illuminance level, standards, activity in the room and cultural preferences. Kruithof diagram shows that the comfortable zone depends on the CCT and the illuminance level. Sources : Architecture et Climat Kruithoh diagram

homeaboutpartnersnewsdownloads principlesin depthapplicationsteaching resourceslearning resourcesin depth Artificial Lighting Lamps -Color rendering index (CRI) is the ability of a light source to reproduce the color of visible spectrum without changing color. The CRI varies from 0 to 100. a CRI of 100 means a complete spectrum, continue and with the same caracteristic that the sunlight Colors perception Very goodgood bad Very bad Not defin ed category1A1B2A2B34- CRI <20 Incandescent* fluorescent tube***** CFL** High pressure mercury** Metal halide**** High pressure sodium**** Low pressure sodium* Sources : Architecture et ClimatSources :

homeaboutpartnersnewsdownloads principlesin depthapplicationsteaching resourceslearning resourcesin depth Artificial Lighting Lamps 2.3. geometrical chacacteristic Operating position Some lamps have to be used in certain positions. If this recommended position is not respected. The lifetime risk to be shorter than predict. - The halide quartz tube of halide could break. - The gas-discharge lamp could not restituate the color correctly Dimensions/size Aestheticism 2.4. economical charcateristic The cost The lifetime (h) can be determined for a lamp or a lot of lamps. -The lamp lifetime is number of hours during wich the lamp was operating before to be useless. - Average in a lot of lamp is the number of hours during wich the lamps were operating until 50% are useless. - The life time of a lot of lamp is the number of hours after wich they emit less than 80% of the original stream. « Useless » does’nt have the same signification in USA and in Europe. -USA : it means that the lamp does’nt work at all. -Europe : it means that the lamp emit less than 70% (85 % for incendescent) of the original stream. Decrease of percentage of lamps operating after x hours of use for two different ballasts Sources : Architecture et Climat

homeaboutpartnersnewsdownloads principlesin depthapplicationsteaching resourceslearning resourcesin depth Artificial Lighting Lamps 2.5. ecological characteristic Labeling : European directive 98/11/EC deals with the energy labeling of household lamps. This label classify lamp in function of the efficiency determined by the main characteristic of the lamp : -Luminous flux -Power -Lifetime The category separation depends on the power and the efficiency (see the graph) “A” represents the best category and “G” the worst category. Recycling : Some lamps contain polluants elements. For example, the gas- discharge lamp contain mercury. This mercury have to recovered. When lamps are useless, it is primordial to depose it in container park or to return it in shop. The accumulation of lamps in the household waste could lead to environment pollution. Sources : Architecture et Climat