Basic Lighting Design Seminar

Transcription

1 Basic Lighting Design Seminar GEWISS GULF - Dubai Date: 29 th May 2009 GEWISS GULF welcomes all members of IIEE.

2 PROGRAM: Basic Lighting Design Seminar 1. BASIC LIGHTING PRINCIPLES 2. INDUSTRIAL& COMMERCIAL LIGHTING PRODUCT RANGE 3. SPORTS AND LARGE AREAS LIGHTING FLOODLIGHTS. 4. STREET LIGHTING PRODUCT RANGE 5. PROLITE 6.0: INTERIOR-EXTERIOR-STREET 6. CASE STUDY CAR SHOW ROOM

3 BASICS of LIGHTING

4 Basic Lighting Contents Nature and perception of light Photometric units of measure Photometric diagrams and optics Lamps and electrical auxiliaries

5 PART 1: NATURE AND PERCEPTION OF LIGHT

6 The Lighting Rays Human eye can distinguish and see only the electromagnetic rays with wavelengths between 380 nm and 780 nm (nm = nanometre = mm).

7 Electromagnetics Spectrum The sunlight appears white at the human eye. But in reality the white light doesn t exist it s the result of the mixture of all the spectrum colours, starting from the violet, through the yellow, to the red colour.

8 Visual Capacity The visual capacity of the human eye in the range of the visible frequency is not linear but the sensibility changes depending on the value of the wavelength of the electromagnetic ray. Relative visibility factor

9 Colour Perception the color perception is strictly related to the lamp type, and completely subjective and changes from observer to observer. clear colors appear more lit than the dark ones, the surface type (rough or smooth) influences the color perception The aim of artificial lighting is to obtain a general level of well-being and comfort light.

10 Test This simple test measures the capacity of the human eye to distinguish different chromatic levels. 26 Which number do you see?

11 Artificial Light (1 of 4) The colour temperature of the lamp is measured in Kelvin (K). The range goes from 2,700K (warm light) to 6,000K (cold light). light source Kelvin clear sky 15,000-20,000 cloudy sky 5,000-15,000 midday sun 6,000 dawn sun 1,500 metal halide 4,000-6,500 fluorescent lamp 3,000-6,500 incandescent lamp 2,000-3,000

12 4000K 5000K 6500K 2700K 3000K 3500K

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14 Artificial Light (2 of 4) Lamps with low colour temperature are identified as WARM, lamps with high colour temperature are identified as COLD. Similar colour temperature lamps could have different spectrum distribution. As a resultthe perceptionof the colourof the objectcouldbe verydifferent. Colour temperature: warm < 3,000 K neutral 3,000-5,000 K cold > 5,000 K LampAhasanemissionmore intensive in the redcolour. The lampbcoversthe whole spectrum.

15 Artificial Light (3 of 4) Colour Rendering Index (R a ): a quantitative measure of the ability of a light source to reproduce the colors of various objects faithfully in comparisonwith an ideal or natural light source. Light sources with a high (Ra) are desirable in color-critical applications such as photography and cinematography

16 Artificial Light (4 of 4) ColourRenderingisin classesthe capabilityof a lampto reproducethe originalcolourof the object. The value ranges between 0 and 100. High index values give more accurate colours appreciation. The original colour is considered the colour of the object whenitislitfroma naturalsourcelikethe sun. Class Ra Colour rendering 1A >90 very good 1B good discreet acceptable 4 < 40 not sufficient

17 PART 2: PHOTOMETRICS UNITS OF MEASURE

18 luminous flux illumination intensity efficiency luminance

19 Units of Measure LUMINOUS FLUX: It is the measure of the perceived power of light. The SI unit of luminous flux is the lumen (lm). The luminous flux is a weighted sum of the power at all wavelengths in the visible band. Light outside the visible band does not contribute. The ratio of the total luminous flux to the radiant flux is called theluminous efficiency

20 Units of Measure LUMINOUS INTENSITY: measures the quantity of lighting energy through a specific direction in candle (cd). sprinkler sprinkler

21 Units of Measure ILLUMINATION: is the amount of incident luminous flux on a surface per unit area.it is measured in lux (lx), lux (= lm/m²) ILLUMINATION

22 ILLUMINATION The illumination on a surface decreases with the square of the distance. Double distancebetweenthe sourceand the surface means ¼ illumination level. sprinkler Sameconsiderationappliesforthe angle betweenthe sourceand the surface. A perpendicularexpositionmaximizesthe levelof lighting, thatdecreaseswiththe angle of incidence.

23 Test 1m 100 lux 2m 100/(1+2)²= 100/9 = 11 lux??? lux

24 ILLUMINATION LEVELS Visual task Summer day, with sun Summer day, cloudy Shop-windows Offices Home Street (night level) Night with moon Night without moon Illumination (lux) 100,000 10,000 2,000-3,

25 Units of Measure LUMINANCE: is the relationship between the luminous intensity in a given direction and the area of the surface. It is measured in candles per square meter (cd/m 2 ). It describes the amount of light that passes through or is emitted from a particular area, and falls within a given solid angle. The luminance indicates how much luminous power will be perceived by an eye looking at the surface from a particular angle of view. Luminance is thus an indicator of how bright the surface will appear LUMINANCE

26 LAMP EFFICIENCY Lampefficiencyisdefinedasthe ratio betweenthe lumen and watt. Thisparameterhelpstodefinethe characteristics of a lamp in comparison with other lamp types. running costs To define the Luminaire efficiency other characteristics must be taken into consideration(reflectortype, material, glass, filters, etc..). power consumption Luminaire efficiency is expressed in percentage.

27 Light rays area Light source. Energy emission Light received Efficiency Specific direction luminous flux intensity lumen (lm) candle (cd) illumination luminance lux (lx) candle/ m 2 (cd/m 2 ) efficiency lumen/watt (lm/w)

28 PART 3: LAMPS AND ELECTRICAL AUXILIARIES

29 LIGHT SOURCES (1 of 2) Incandescent lamps Incandescent lamps are heat radiators as the sun in nature. Some of the generated heat is given out in the form of light. Discharge lamps Discharge lamps are light radiators as the lightning in nature. Light is generated from the direct transformation of the electrical power into luminous power.

30 LIGHT SOURCES (2 of 2) incandescent halogen mercury vapour fluorescent filament lamps discharge lamps metal halide with reflector sodium vapour induction

31 LUMINOUS EFFICIENCY Inc andescent Halogen M ercury Fluorescent Metal Halide Sodium In theory1w of energy power shouldproduce about lumen. Whythereare lampswith much lower efficiency? Where is the energy being lost? Large part of energy (up to 90%) is transformed in heat reducing the efficiency coefficient lm/w. Partof the total emissionof the lampisout of the visiblerange, i.e. in the UV and IR partof the spectrum.

32 ELECTRICAL COMPONENTS IGNITOR BALLAST PFC CAPACITOR A device to trig a discharge lamp, also ensuring the pre-heating of the electrodes. A device to provide constant power supply to discharge lamps. A device to reduce power consumption of discharge lamps.

33 PART 4:PHOTOMETRIC DIAGRAMS AND OPTICS

34 PHOTOMETRIC DIAGRAMS The intensity of the light emission on each direction can be represented by a diagram on which every light ray starting from the lamp has a length corresponding to its intensity value. Connecting all these segments we are able to design the photometric solid.

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36 MOST USED DIAGRAMS Light beam Isolux diagram Polar diagram

37 DIFFERENT OPTICS Restricted Diffusing

38 POLAR AND CARTESIAN CURVES Polar diagram Cartesian diagram To compare different lamps and luminaires, all diagrams refer to a source with a nominalfluxof 1,000 lm. cd/klm

39 DIRECT-INDIRECT DIFFUSION Direct emission(symmetrical and asymmetrical): the luminous flux is emitted directly on the surface. Indirectemission:the luminousfluxisreflectedbyanothersurface.

40 SYMMETRICAL DIFFUSION The light beam is symmetric in respect to the centre of the luminaire. Sometimes the light beam can be manually adjusted. This means: LARGER BEAM LESS LUX

41 ASYMMETRICAL DIFFUSION The lighting beam is asymmetric in respect to the centre of the luminaire.

42 THANK YOU