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OBTRUSIVE LIGHTING. Direct glare SPILL LIGHT SKY GLOW Obtrusive light Area to be lit Upward direct light Upward reflected light Definitions.

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Presentation on theme: "OBTRUSIVE LIGHTING. Direct glare SPILL LIGHT SKY GLOW Obtrusive light Area to be lit Upward direct light Upward reflected light Definitions."— Presentation transcript:

1 OBTRUSIVE LIGHTING

2 Direct glare SPILL LIGHT SKY GLOW Obtrusive light Area to be lit Upward direct light Upward reflected light Definitions

3 Three phenomena are related to light control of luminaires and their installation  Glare All are the result of waste of energy  Obtrusive light  Sky glow

4 Glare the most critical problem As it has to do with safety of drivers and pedestrians  Threshold Increment TI limitation for road lighting  Glare Rating GR limitation for large area

5  1° E Disability glare - TI (CIE 140) K E 22 and Lv = TI = 65 LvLv L R 0.8  10% or 15%

6 Glare Rating - GR (CIE 112) GR = lg (L vl / L ve 0.9 ) WithL vl = veiling luminance produced by luminaires L ve = veiling luminance produced by environment andL ve = L av withL av = E H.  

7 Glare Ratio GR Unbearable Disturbing Just admissible50 Noticeable Unnoticeable Glare Rating limitation

8 Glare control At design stage : On site : Calculation of TI or GR Cannot be measured

9 Obtrusive light Light falling out of the area of interest, causing disturbances or reducing confort By – over lighting – stray light – bad wave length

10 CIE zoning system (CIE Nr. 126) Zone rating Description E1Areas with intrinsically dark lanscapes E2Areas of ’’low district brightness ’’ E3Areas of ’’middle district brightness ’’ E4Areas of ’’high district brightness ’’

11 CIE zoning system Application of CIE Nr. 150 Zone rating SurroundingExamples E1NaturalNational parks or protected sites E2RuralIndustrial or residential rural areas E3SuburbanIndustrial or residential suburbs E4UrbanTown centres and commercial areas

12 CIE zoning system Light Technical parameter Application conditions Environmental Zones E1E2E3E4 Illuminance In vertical Plane ( E v ) Pre-curfew :2 lux5 lux10 lux25 lux Post-curfew :0* lux1 lux2 lux5 lux Maximum values of E V on properties - CIE 150

13 CIE zoning system Light Technical parameter Application conditions Environmental Zones E1E2E3E4 Luminous Intensity Emitted by Luminaires (I) Pre-curfew : 2500 cd7500 cd10000 cd25000 cd Post-curfew Hours : 0 cd*500 cd1000 cd2500 cd Maximum values of I (cd) in specific directions - CIE 150

14 Limitation of effects on transport system - CIE 150 Light Technical Parameter Road Classification No road lighting M5M4 / M3M2 / M1 Threshold Increment TI 15% based on adaptation luminance of 0.1 cd/m² 15% based on adaptation luminance of 1 cd/m² 15% based on adaptation luminance of 2 cd/m² 15% based on adaptation luminance of 5 cd/m² CIE zoning system

15 Limitation of effects on over lit building and signs CIE 150 CIE zoning system Parameter Application Conditions Environmental Zones E1E2E3E4 Building Facade Luminance (L b ) 0 cd/m²5 cd/m²10 cd/m² 25 cd/m² Sign Luminance (L s ) 50 cd/m² 400 cd/m² 500 cd/m² 1000 cd/m² E AV x    or L AV

16 SKY GLOW Definition : Brightening of night sky resulting from reflection of radiations scattered from the constituents of the atmosphere in direction of observation

17

18 Sky glow SKY GLOW

19 - Artificial lighting installations  direct upward light  upward reflected light - Headlights of vehicules - Atmosphere pollution - Atmosphere humidity - Clouds - Radiation from celestian sources Many factors contribute to sky glow

20 SKY GLOW  advertising signs ;  area lighting of sales areas, parking lots, etc..  floodlighting of buildings, discos and monuments  lighting of billoards ;  lighting of greenhouses ;  lighting of industrial site, airports and buiding sites  lighting of sports facilites  road and street lighting Stray light due to artificial lighting

21 SKY GLOW First approach : CIE 126 (1997)

22 SKY GLOW CIE Zoning system - CIE 126 Zone ratingULOR inst (%)Astronomical acivities E10 Observatories of (inter)national standing E20 – 5Postgraduate and academic studies E Undergraduate studies, amateur observation E Casual sky viewing

23 SKY GLOW Minimum distance (in km) between zone borderlines and ref. point Zone rating of reference point Zone rating surrounding zones distance (km) tobordeline of surrounding zones E1 – E2E2 – E3E3 – E4 E E21100 E31 E4 No limits

24 Definitions ULOR = % of flux of the lamp(s) of a luminaire above horizontal DLOR = % of flux of the lamp(s) of a luminaire below horizontal  = DLOR + ULOR

25 Definitions ULR = % of flux of a luminaire above horizontal UWLR ULOR inst ULR = DLOR + ULOR ULOR

26 CIE recommandation for the limitation of sky glow Zone ratingULOR inst (%) E10 E20 – 5 E30 – 15 E

27 Sky glow limitation Second (our) approach : Limitation of UPF ( UP ward F lux )

28 DLOR ULOR (DLOR-K) 11 22 22 Where  = ULOR + DLOR, i.e.   = ULOR + K + (DLOR-K) K

29 FLUX OF THE LAMP DIRECT FLUX UPWARDS REFLECTION ON THE ROAD REFLECTION ON SURROUNDINGS Then,  upwards (potential) =  lamp x % of rays going upwards

30 Depends on : E resquested by standards S surface to be lit : political decision The nature of the surfaces to be lit and the surroundings: we have very little influence on this choice These are the luminaire features, where we can have a say

31 How can we influence the  upwards (potential) ? Finding the good compromise between :  Reducing ULOR  Increasing K (as close as possible to DLOR)  Optimizing the E/L ratio for road lighting installations Getting the best possible photometry But being aware that there is no magic recipe (due to the uncertainty on the surfaces reflection properties, especially on the surroundings’)

32 In many occasions, low depth glasses (Onyx, Saphir and MC low deeps, Image,…) are the best photometrical compromise But flat glasses are good enough a lot of times too and... USE OF FLAT GLASS IS WIDELY ACCEPTED BY ASTRONOMERS But we must not forget that for some , deep protectors (that have higher ULOR) and even refractors are a less “polluting” solution than the others!!! Road lighting applications

33  High pollution

34 Reducing ULOR Flat glass at 0°? Curved glass protector is often the best solution

35  Recommendations for other installation  Do not “over” light  Direct light downwards  Keep beam below 70°  Take care with location and height of poles  70° <70°

36 Lower aiming possible Use of narrow beam floodlight possible Higher aiming necessary Use of wider beam floodlight may be necessary (a) Higher mounting heights – less spill and glare (b) Lower mounting heights – more spill light and glare

37 Floodlighting Use asymetric light distribution

38 Focal Neos 3 Citea Louvers and shades to be used adequately

39 Recommendations for all lighting installations Use high IP luminaires Realise the most efficient lighting solution in long term condition

40 Thank you for your attention


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