The SLL Lighting Handbook

The SLL Lighting Handbook The Society of Light and Lighting 222 Balham High Road, London SW12 9BS +44(0)20 8675 5211 www.cibse.org

CONTENTS PART 1: FUNDAMENTALS Chapter 1: Light 1.1 The nature of light 1 1.2 The CIE standard observers 1 1.3 The measurement of light photometry 3 1.3.1 Luminous flux 3 1.3.2 Luminous intensity 3 1.3.3 Illuminance 4 1.3.4 Luminance 4 1.3.5 Reflectance 4 1.3.6 Obsolete units 6 1.3.7 Typical values 6 1.4 The measurement of light colourimetry 7 1.4.1 The CIE chromaticity diagrams 7 1.4.2 The CIE colour spaces 10 1.4.3 Correlated colour temperature 11 1.4.4 CIE colour rendering index 12 1.4.5 Colour gamut 13 1.4.6 Scotopic/photopic ratio 14 1.4.7 Colour order systems 14 Chapter 2: Vision 2.1 The structure of the visual system 16 2.1.1 The visual field 16 2.1.2 Eye movements 16 2.1.3 Optics of the eye 17 2.1.4 The structure of the retina 19 2.1.5 The functioning of the retina 22 2.1.6 The central visual pathways 23 2.1.7 Colour vision 23 2.2 Continuous adjustments of the visual system 24 2.2.1 Adaptation 24 2.2.2 Photopic, scotopic and mesopic vision 25 2.2.3 Accommodation 26 2.3 Capabilities of the visual system 26 2.3.1 Threshold measures 26 2.3.2 Factors determining visual threshold 28 2.3.3 Spatial thresholds 28 2.3.4 Temporal thresholds 30 2.3.5 Colour thresholds 31 2.3.6 Light spectrum and movement 32 2.4 Suprathreshold performance 32 2.5 Visual search 34 2.6 Visual discomfort 37 2.6.1 Insufficient light 37 2.6.2 Illuminance uniformity 37 2.6.3 Glare 38 2.6.4 Veiling reflections 39 2.6.5 Shadows 40 2.6.6 Flicker 41

2.7 Perception through the visual system 41 2.7.1 The constancies 41 2.7.2 Attributes and modes of appearance 42 2.8 Anomolies of vision 44 2.8.1 Defective colour vision 44 2.8.2 Low vision 45 PART 2: TECHNOLOGY Chapter 3: Light sources 3.1 Production of radiation 48 3.1.1 Incandescence 48 3.1.2 3.1.3 3.1.4 3.1.5 3.1.6 3.1.7 3.1.8 3.2 Daylight 3.2.1 3.2.2 Electric discharges Electroluminescence Luminescence Radioluminescence Cathodoluminescence Chemiluminescence Thermoluminescence Sunlight Skylight 3.3 Electric light 3.3.1 Incandescent 3.3.2 Tungsten halogen 3.3.3 Fluorescent 3.3.4 High pressure mercury 3.3.5 Metal halide 3.3.6 Low pressure sodium 3.3.7 High pressure sodium 3.3.8 Induction 3.3.9 Light emitting diodes 3.3.10 Electroluminescent 3.4 Electric light source characteristics 3.4.1 3.4.2 3.4.3 3.4.4 3.4.5 3.4.6 3.4.7 3.4.8 3.4.9 3.4.10 3.5 Flames 3.5.1 3.5.2 3.5.3 Luminous flux Power demand Luminous efficacy Lumen maintenance Life Colour properties Run-up time Restrike time Other factors Summary of lamp characteristics Candle Oil Gas 49 51 51 51 52 52 52 52 52 54 57 57 59 60 64 66 69 70 74 75 76 77 77 77 78 78 78 78 78 79 79 79 82 82 82 83

Chapter 4: Luminaires 4.1 Basic requirements 4.1.1 Electrical 4.1.2 Mechanical 4.1.3 Optical control 4.1.4 Efficiency 4.1.5 Thermal 4.1.6 Acoustics 4.1.7 Environmental 4.2 Luminaire types 4.2.1 Interior lighting 4.2.2 Exterior lighting 4.3 Certification and classification 4.3.1 4.3.2 Certification Classification Chapter 5: Electrics 5.1 Control gear 5.1.1 Ballasts for discharge light sources 5.1.2 Transformers for low voltage light sources 5.1.3 Drivers for LEDs 5.2 Lighting controls 5.2.1 Options for control 5.2.2 Input devices 5.2.3 Control processes and systems PART 3: APPLICATIONS Chapter 6: Lighting design 6.1 Objectives and constraints 6.2 A holistic strategy for lighting 6.2.1 Legal requirements 6.2.2 Visual function 6.2.3 Visual amenity 6.2.4 Lighting and architectural integration 6.2.5 Energy efficiency and sustainability 6.2.6 Maintenance 6.2.7 Lighting costs 6.2.8 Photopic or mesopic vision 6.2.9 Light trespass and skyglow 6.3 Basic design decisions 6.3.1 Use of daylight 6.3.2 Choice of electric lighting system 6.3.3 Integration 6.3.4 Equal and approved Chapter 7: Daylighting 7.1 Benefits of daylight 7.2 Daylight availability 7.3 Daylight as a contribution to room brightness 7.4 Daylight for task illumination 84 84 85 86 91 91 93 94 94 94 98 100 100 105 109 109 114 114 115 115 115 116 117 117 118 118 119 120 120 121 121 121 122 124 124 124 125 128 129 131 133 133 I

7.5 Types of daylighting 7.5.1 Windows 7.5.2 Clerestories 7.5.3 Rooflights 7.5.4 Atria 7.5.5 Remote distribution 7.5.6 Borrowed light 7.6 Problems of daylighting 7.6.1 Visual problems 7.6.2 Thermal problems 7.6.3 Privacy problems 7.7 Maintenance Chapter 8: Emergency Sighting 8.1 Legislation and standards 8.2 Forms of emergency lighting 8.2.1 Escape route lighting 8.2.2 Signage 8.2.3 Open area lighting 8.2.4 High risk area 8.2.5 Standby lighting 8.3 Design approaches 8.4 Emergency lighting equipment 8.4.1 Power sources 8.4.2 Circuits 8.4.3 Luminaires 8.4.4 Luminaire classification 8.4.5 Light sources 8.4.6 Others 8.5 Scheme planning 8.5.1 Risk assessment 8.5.2 Recommended systems for specific places 8.5.3 Planning sequence 8.6 Installation, testing and maintenance 8.6.1 Installation 8.6.2 Maintenance and inspection 8.6.3 Documentation 8.6.4 Commissioning and certification 8.6.5 Completion certificate Chapter 9: Office lighting 9.1 Functions of lighting in offices 9.2 Factors to be considered 9.2.1 Legislation and guidance 9.2.2 Type of work done 9.2.3 Screen type 9.2.4 Daylight availability 9.2.5 Ceiling height 9.2.6 Obstruction 9.2.7 Surface finishes

9.3 Lighting recommendations 162 9.3.1 Illuminances 162 9.3.2 Light distribution 164 9.3.3 Maximum luminances 165 9.3.4 Discomfort glare control 166 9.3.5 Light source colour properties 167 9.4 Approaches to office lighting 168 9.4.1 Direct lighting 168 9.4.2 Indirect lighting 169 9.4.3 Direct/indirect lighting 170 9.4.4 Localised lighting 170 9.4.5 Supplementary task lighting 171 9.4.6 Cove lighting 171 9.4.7 Luminous ceilings 172 9.4.8 Daylight 172 Chapter 10: Industrial lighting 10.1 Functions of lighting in industrial premises 173 10.2 Factors to be considered 173 10.2.1 Legislation and guidance 173 10.2.2 The environment 174 10.2.3 Daylight availability 174 10.2.4 Need for good colour vision 175 10.2.5 Obstruction 175 10.2.6 Directions of view 176 10.2.7 Access 177 10.2.8 Rotating machinery 177 10.2.9 Safety and emergency egress 177 10.3 Lighting recommendations 177 10.3.1 Control rooms 178 10.3.2 Storage 180 10.3.3 Ancillary areas 181 10.3.4 Speculative factory units 182 10.4 Approaches to industrial lighting 182 10.4.1 General lighting 182 10.4.2 Localised lighting 183 10.4.3 Local lighting 183 10.4.4 Visual inspection 183 10.4.5 Visual aids 184 Chapter 11: Lighting for educational premises 11.1 Functions of lighting for educational premises 185 11.2 Factors to be considered 185 11.2.1 Students' capabilities 185 11.2.2 Daylight or electric light 186 11.2.3 Common lines of sight 186 11.2.4 Flat or raked floor 186 11.2.5 Presence of visual aids 186 11.2.6 Surface finishes 186

11.3 Lighting recommendations 187 11.3.1 Illuminances 187 11.3.2 11.3.3 11.3.4 11.3.5 Illuminance uniformity Glare control Light source colour properties Control systems 11.4 Approaches to lighting educational premises 11.4.1 Classrooms and lecture halls 11.4.2 IT room 11.4.3 Arts studio 11.4.4 Science laboratories 11.4.5 Seminar room 11.4.6 Library 11.4.7 Assembly hall 11.4.8 Music room 11.4.9 Drama studio 187 187 188 188 189 189 189 189 189 190 190 190 190 190 Chapter 12: Retail fighting 12.1 Functions of retail lighting 191 12.2 Factors to be considered 191 12.2.1 Shop profile 191 12.2.2 Daylight or electric light 192 12.2.3 Nature of merchandise 192 12.2.4 Obstruction 192 12.3 Lighting recommendations 192 12.3.1 Illuminances 192 12.3.2 Illuminance uniformity 193 12.3.3 Luminances 193 12.3.4 Light source colour properties 193 12.4 Approaches to retail lighting 194 12.4.1 General lighting 194 12.4.2 Accent lighting 194 12.4.3 Display lighting 195 Chapter 13: Lighting for museums and art galleries 13.1 Functions of lighting in museums and art galleries 198 13.2 Factors to be considered 198 13.2.1 Daylight or electric light 198 13.2.2 Conservation of exhibits 198 13.2.3 Light source colour rendering properties 199 13.2.4 Adaptation 199 13.2.5 Balance 199 13.2.6 Shadows and modelling 200 13.2.7 Glare 200 13.2.8 Veiling reflections and highlights 200 13.2.9 Out-of-hours activities 200 13.2.10 Security and emergency 201 13.2.11 Maintenance 201 13.2.12 Flexibility 201 13.3 Lighting approaches for museums and art galleries 201 13.3.1 Wall mounted displays 201 13.3.2 Three-dimensional displays 201 13.3.3 Showcase lighting 202

Chapter 14: Lighting for hospitals 14.1 Functions of lighting in hospitals 203 14.2 Factors to be considered 203 14.2.1 Daylight 203 14.2.2 Lines of sight 203 14.2.3 Colour rendering requirements 203 14.2.4 Observation without disturbance to sleep 204 14.2.5 Emergency lighting 204 14.2.6 Luminaire safety 204 14.2.7 Cleanliness 205 14.2.8 Electro-magnetic compatibility (EMC) 205 14.3 Approaches for the lighting of different areas in hospitals 205 14.3.1 Entrance halls, waiting areas and lift halls 206 14.3.2 Reception and enquiry desks 206 14.3.3 Hospital streets and general corridors 207 14.3.4 Changing rooms, cubicles, toilets, bath, wash and shower rooms 207 14.3.5 Wards 207 14.3.6 Reading lighting 211 14.3.7 Night lighting 211 14.3.8 Night observation lighting (watch lighting) 211 14.3.9 Clinical areas and operating departments 212 14.3.10 Operating theatres 212 Chapter 15: Quasi-domestic lighting 15.1 Functions of quasi-domestic lighting 214 15.2 Factors to be considered 214 15.2.1 Occupants' capabilities 214 15.2.2 Daylight 214 15.2.3 Light source colour properties 214 15.2.4 Energy efficiency 215 15.2.5 Safety 215 15.2.6 Security 216 15.3 Lighting recommendations 216 15.4 Approaches to lighting quasi-domestic buildings 217 15.4.1 Entrances 217 15.4.2 Corridors and stairs 217 15.4.3 Study bedrooms 218 15.4.4 Kitchens and utility rooms 218 15.4.5 Lounges 219 15.4.6 Dining halls 219 15.4.7 Games room 219 Chapter 16: Road lighting 16.1 Road classification 220 16.2 Lighting for traffic routes 220 16.2.1 Lighting recommendations for traffic routes 220 16.2.2 Lighting recommendations for areas adjacent to the carriageway 223 16.2.3 Lighting recommendations for conflict areas 224 16.2.4 Coordination 225 16.2.5 Traffic route lighting design 225

16.3 Lighting for subsidiary roads 230 16.3.1 Lighting recommendations for subsidiary roads 230 16.3.2 Lighting design for subsidiary roads 232 16.4 Lighting for urban centres and public amenity areas 232 16.5 Tunnel lighting 233 Chapter 17: Exterior workplace fighting 17.1 Functions of lighting in exterior workplaces 236 17.2 Factors to be considered 236 17.2.1 Scale 236 17.2.2 Nature of work 236 17.2.3 Need for good colour vision 237 17.2.4 Obstruction 237 17.2.5 Interference with complementary activities 237 17.2.6 Hours of operation 237 17.2.7 Impact on the surrounding area 238 17.2.8 Atmospheric conditions 238 17.3 Lighting recommendations 238 17.3.1 Illuminance and illuminance uniformity 238 17.3.2 Glare control 239 17.3.3 Light source colour properties 239 17.3.4 Loading areas 239 17.3.5 Chemical and fuel industries 240 17.3.6 Sidings, marshalling yards and goods yards 241 17.4 Approaches to exterior workplace lighting 243 17.4.1 High mast floodlighting 243 17.4.2 Integrated lighting 243 17.4.3 Localised lighting 244 Chapter 18: Security lighting 18.1 Functions of security lighting 245 18.2 Factors to be considered 245 18.2.1 Type of site 245 18.2.2 Site features 246 18.2.3 Ambient light levels 247 18.2.4 Crime risk 247 18.2.5 CCTV surveillance 247 18.2.6 Impact on the surrounding area 247 18.3 Lighting recommendations 247 18.3.1 Illuminance and illuminance uniformity 247 18.3.2 Glare control 249 18.3.3 Light source colour properties 249 18.4 Approaches to security lighting 249 18.4.1 Secure areas 249 18.4.2 Public spaces 252 18.4.3 Private areas 253 18.4.4 Multi-occupancy dwellings 254 18.5 Lighting Equipment 254 18.5.1 Light sources 254 18.5.2 Luminaires 255 18.5.3 Lighting columns 255 18.5.4 Lighting controls 256 18.5.5 Maintenance 256

Chapter 19: Sports lighting 19.1 Functions of lighting for sports 257 19.2 Factors to be considered 257 19.2.1 Standard of play and viewing distance 257 19.2.2 Playing area 258 19.2.3 Luminaires 258 19.2.4 Television 258 19.2.5 Coping with power failures 259 19.2.6 Obtrusive light 260 19.3 Lighting recommendations 261 19.3.1 Athletics 261 19.3.2 Bowls 262 19.3.3 Cricket 263 19.3.4 Five-a-side football (indoor) 264 19.3.5 Fitness training 264 19.3.6 Football (Association, Gaelic and American) 265 19.3.7 Lawn tennis 265 19.3.8 Rugby (Union and League) 266 19.3.9 Swimming 266 19.4 Lighting in large facilities 267 19.4.1 Multi-use sports halls 267 19.4.2 Small sports stadia 267 19.4.3 Indoor arenas 268 19.4.4 Swimming pools 268 Chapter 20: Lighting performance verification 20.1 The need for performance verification 270 20.2 Relevant operating conditions 270 20.3. Instrumentation 271 20.3.1 Illuminance meters 271 20.3.2 Luminance meters 271 20.4 Methods of measurement 272 20.4.1 Average illuminance 272 20.4.2 Interior lighting 272 20.4.3 Exterior lighting 274 20.5 Measurement of illuminance variation 275 20.5.1 Illuminance diversity 275 20.5.2 Illuminance uniformity 276 20.6 Luminance measurements 276 20.7 Measurement of reflectance 276 Chapter 21: Lighting maintenance 21.1 The need for lighting maintenance 278 21.2 Lamp replacement 278 21.3 Cleaning luminaires 278 21.4 Room surface cleaning 280 21.5 Maintained illuminance 280 21.6 Designing for lighting maintenance 280 21.7 Determination of maintenance factor for interior lighting 280 21.7.1 Lamp lumen maintenance factor (LLMF) 281 21.7.2 Lamp survival factor (LSF) 281 21.7.3 Luminaire maintenance factor (LMF) 282 21.7.4 Room surface maintenance factor (RSMF) 284

21.8 Determination of maintenance factor for exterior lighting 21.9 Disposal of lighting equipment Chapter 22: On the horizon 22.1. Changes and challenges 22.2. The changes and challenges facing lighting practice 22.2.1 Costs 22.2.2 Technologies 22.2.3 New knowledge 22.2.4 External influences 22.3 The evolution of lighting practice Chapter 23: Bibliography 23.1 Standards 23.2 Guidance 23.3 References Index 303