Exterior Lighting: Exterior Lighting Flood lighting, Sports lighting, Road lighting, Façade lighting, Runway PowerPoint Presentation: LED lighting systems 2 PURPOSE: PURPOSE The lighting of an object or area so that it becomes brighter than its surroundings The level of illumination required for a particular application depends greatly upon seeing the task involved and upon the surrounding conditions Lighting objectives: Safety Performance( to allow work to be carried out in the night) Enhanced appearance to advertise To model a feature such as a statue To enable sporting events to be seen by spectators or to be televised LED lighting systems 3 IMPORTANT FACTORS: IMPORTANT FACTORS Luminance contrast between the object and the surroundings Beam spread of the luminaires – polar curve Type of the lamp Position or location of projectors Background luminance Nature of surface to be lit Atmospheric losses Maintenance factor Glare LED lighting systems 4 APPLICATION: APPLICATION Aesthetic Heritage buildings, monuments, statues, religious buildings – canopies , malls, city functions etc. Advertisement Advertisement Boards, showcases etc. Commercial Railway yards, car parking area, bus stand, large industrial area, sports ground, construction sites etc. LED lighting systems 5 PowerPoint Presentation: LED lighting systems 6 LIGHT SOURCES USED: LIGHT SOURCES USED Fluorescent lamps should not be used for flood lighting as they make the surfaces to appear flat Tungsten Halogen lamps Application demanding perfect CRI – 500W, 1000W, 2000W Drawbacks loss of heat production, less energy efficient, short life, needs more maintenance HPSV lamps: Improved CRI – 60-80 Lesser heat production, high luminous efficacy, longer life, better lumen maintenance Metal Halide lamps: Used depending on the color rendering requirements Lesser heat production, high luminous efficacy Both tubular and elliptical shapes used – divergent beam LED lighting systems 7 PowerPoint Presentation: LED lighting systems 8 LOCATION OF EQUIPMENTS: LOCATION OF EQUIPMENTS Small buildings: simple architecture Illuminating the building uniformly Projectors may be placed on the roofs of the neighboring buildings or on the curb side posts Distance of the building from the projectors should not be more than 50m Equipment so located that the incident light is received perpendicularly by the building Large buildings: set back features, covers and projecting surfaces Illuminating the building non-uniformly Projectors may be placed in the parapets or hidden within the projecting features of the building or on the lintels Illumination level required: 50-450 lux LED lighting systems 9 PowerPoint Presentation: LED lighting systems 10 LOCATION OF EQUIPMENTS: LOCATION OF EQUIPMENTS Monuments and statues: Located in such positions so as to produce nature soft shadows which promotes 3-D appearance Lamps must have good CRI property Light should come from above the horizontal and also from several angles such that a good modeling effect is produced Ground surfaces: Equipment should be located on the towers or high mast structure or on the roof of adjacent tall building Luminance level must be higher than dictated by the visual needs of the player Keeping the glare as minimum as possible, the lights are to be mounted as high as possible LED lighting systems 11 PowerPoint Presentation: LED lighting systems 12 TYPES OF EQUIPMENTS: TYPES OF EQUIPMENTS Enclosed Consists of a reflector and a high intensity lamp mounted inside a metal housing and covered with glass or plastic panels or lenses Perfectly sealed and gasketted to prevent the entry of dirt, moisture and dust More accurate beam control, less maintenance and hence higher M.F., more permanence in construction, costlier Open Suitable for broad angle projection Bowl shaped – reflectors made of polished aluminium , chromium plates or porcelain enameled steel Suitable when light is to be projected horizontally or downwards Lower cost, light weight, lesser size, hence lesser cost of the poles LED lighting systems 13 Projectors are classification: Projectors are classification Narrow beam projectors : beam spread between 12 – 25; used for distances beyond 10m Medium beam projectors : beam spread between 25 -- 40; used for distances 30m – 70m Wide beam projectors : beam spread between 40 – 90; used for distances below 30m LED lighting systems 14 PowerPoint Presentation: LED lighting systems 15 PowerPoint Presentation: LED lighting systems 16 WASTE LIGHT FACTOR: WASTE LIGHT FACTOR Depending on the distance of the projector from the building, dark spots may be created at the corners or spill light may be produced beyond the edges of the surface or the light due to one surface may overlap on the surface Due to all the above reasons, the light may be wasted and hence a WLF is selected For regular surfaces like buildings and advertisement boards – WLF is 1.2 For irregular surfaces like statues and architectural buildings – WLF is 1.5 LED lighting systems 17 C.U.: Depends on lighting system, type of lamp fittings, mounting height of the projectors and nature of surface to be lit Value is lower than interior lighting as there are no inter-reflected light For direct lighting – C.U. is 0.4-0.6 For indirect lighting – C.U. is 0.1-0.35 C.U. DEPRECIATION FACTOR: Accounts for the reduction in the lighting level with time due to Lamp Lumen Depreciation (LLD), Luminaire Dirt and Surface depreciation (LDD & LSD) and Building Surface Dirt Depreciation (BSDD) For installation with regular maintenance – D.F. is 1/1.3 = 0.769, else 1/1.5 = 0.667 DEPRECIATION FACTOR PowerPoint Presentation: Design Calculations E : Recommended surface illuminance : Beam flux WLF : Waste light factor CU : Coefficient of utilization DF : Depreciation factor A : Area to be flood lit Example: Example The front of a building 50m height and 15m wide must be illuminated by flood lighting of projectors to a lux level of 200. The building surface is light coloured with brightly lit background during night time. The building surface has lot of projecting features. The flood lighting projectors are poorly maintained. Assume, U.F = 0.4. Lamps available are; Metal halide, 1000 watt, 80lm/w. H.P.S.V, 750watt, 120lm /w. Suggest a suitable lighting scheme and comment on the beam spread if the projectors are located 15m away from the building.