The Society of Light and Lighting is part of the Chartered Institution of Building Services Engineers The Society of Light and Lighting The SLL Lighting Handbook The Society of Light and Lighting The SLL Lighting Handbook The Society of Light and Lighting The SLL Lighting Handbook 222 Balham High Road, London SW12 9BS +44 (0)20 8675 5211 www.cibse.org Final Lighting book artwork 08 25/3/09 10:04 Page 1 This document is based on the best knowledge available at the time of publication. However, no responsibility of any kind for any injury, death, loss, damage or delay however caused resulting from the use of these recommendations can be accepted by the Chartered Institution of Building Services Engineers, The Society of Light and Lighting, the authors or others involved in its publication. In adopting these recommendations for use each adopter by doing so agrees to accept full responsibility for any personal injury, death, loss, damage or delay arising out of or in connection with their use by or on behalf of such adopter irrespective of the cause or reason therefore and agrees to defend, indemnify and hold harmless the Chartered Institution of Building Services Engineers, The Society of Light and Lighting, the authors and others involved in their publication from any and all liability arising out of or in connection with such use as aforesaid and irrespective of any negligence on the part of those indemnified. The rights of publication or translation are reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means without the prior permission of the publisher. Note from the publisher This publication is primarily intended to give guidance. It is not intended to be exhaustive or definitive, and it will be necessary for users of the guidance given to exercise their own professional judgement when deciding whether to abide by or depart from it. © February 2009 The Society of Light and Lighting The Society is part of CIBSE, which is a registered charity, number 278104. ISBN 978-1-906846-02-2 Project and Print management by entiveon Ltd. www.entiveon.com Design, linework and typsetting by Squarefox Design Ltd. www.squarefox.co.uk Printed in England on FSC certified Mixed Sources paper by Stones the Printers Ltd. www.stonestheprinters.co.uk ii The Society of Light and Lighting is part of the Chartered Institution of Building Services Engineers The Society of Light and Lighting Final Lighting book artwork 08 25/3/09 10:04 Page 2 FOREWORD 2009 is the centenary of the formation of the Illuminating Engineering Society, the progenitor of the Society of Light and Lighting. This handbook has been written to celebrate this anniversary and to fill a gap in the Society’s publications. The Society of Light and Lighting’s major publications are: The SLL Code for lighting, which offers recommendations on lighting for a wide range of applications The SLL Lighting Guides, which provide detailed guidance on specific lighting applications The SLL Lighting Handbook has been written to forge a link between them. It is designed to be complementary to the SLL Code for lighting but to go beyond it in terms of applications and background information without getting into the fine detail of the Lighting Guides. The SLL Lighting Handbook is intended to be the first-stop for anyone seeking information on lighting. It is aimed not just at lighting practitioners but also at lighting specifiers and students of lighting. For all three groups, we have tried to make it comprehensive, up-to-date and easily understandable. The contents summarise the fundamentals of light and vision, the technology of lighting and guidance on a wide range of applications, both interior and exterior. Authors Peter Boyce PhD, FSLL, FIESNA Peter Raynham BSc MSc CEng FSLL MCIBSE MILE Acknowledgements John Fitzpatrick Lou Bedocs (Thorn Lighting) Ted Glenny (Philips Lighting) Jennifer Brons for Figure 20.2 Kit Cuttle for Figures 13.1 and 13.2 Lighting Research Center for Figures 9.1, 10.3, 18.8, 18.9 and 20.3 McGraw Hill Inc, for Figures 2.4 and 2.9 Mick Stevens for Figures 20.3 and 22.1 The Illuminating Engineering Society of North America for Figures 1.5, 1.6, 1.7, 1.8, 2.8 and 2.13 Philips Lighting, iGuzzini Illuminazione, Havells Sylvania & Luxo Charlotte Wood Photography for Figures 14.1, 14.2 and 14.3 Editors Stuart Boreham (entiveon Ltd.) Peter Hadley (Squarefox Design Ltd.) SLL Secretary Liz Peck CIBSE Editorial Manager Ken Butcher CIBSE Director of Information Jacqueline Balian iii Final Lighting book artwork 08 25/3/09 10:04 Page 3 iv Final Lighting book artwork 08 25/3/09 10:04 Page 4 v CONTENTS PART 1: FUNDAMENTALS Chapter 1: Light 1.1 The nature of light 1.2 The CIE standard observers 1.3 The measurement of light — photometry 1.3.1 Luminous flux 1.3.2 Luminous intensity 1.3.3 Illuminance 1.3.4 Luminance 1.3.5 Reflectance 1.3.6 Obsolete units 1.3.7 Typical values 1.4 The measurement of light — colourimetry 1.4.1 The CIE chromaticity diagrams 1.4.2 The CIE colour spaces 1.4.3 Correlated colour temperature 1.4.4 CIE colour rendering index 1.4.5 Colour gamut 1.4.6 Scotopic/photopic ratio 1.4.7 Colour order systems Chapter 2: Vision 2.1 The structure of the visual system 2.1.1 The visual field 2.1.2 Eye movements 2.1.3 Optics of the eye 2.1.4 The structure of the retina 2.1.5 The functioning of the retina 2.1.6 The central visual pathways 2.1.7 Colour vision 2.2 Continuous adjustments of the visual system 2.2.1 Adaptation 2.2.2 Photopic, scotopic and mesopic vision 2.2.3 Accommodation 2.3 Capabilities of the visual system 2.3.1 Threshold measures 2.3.2 Factors determining visual threshold 2.3.3 Spatial thresholds 2.3.4 Temporal thresholds 2.3.5 Colour thresholds 2.3.6 Light spectrum and movement 2.4 Suprathreshold performance 2.5 Visual search 2.6 Visual discomfort 2.6.1 Insufficient light 2.6.2 Illuminance uniformity 2.6.3 Glare 2.6.4 Veiling reflections 2.6.5 Shadows 2.6.6 Flicker 1 1 3 3 3 4 4 4 6 6 7 7 10 11 12 13 14 14 16 16 16 17 19 22 23 23 24 24 25 26 26 26 28 28 30 31 32 32 34 37 37 37 38 39 40 41 Final Lighting book artwork 08 25/3/09 10:04 Page 5 vi 2.7 Perception through the visual system 2.7.1 The constancies 2.7.2 Attributes and modes of appearance 2.8 Anomolies of vision 2.8.1 Defective colour vision 2.8.2 Low vision PART 2: TECHNOLOGY Chapter 3: Light sources 3.1 Production of radiation 3.1.1 Incandescence 3.1.2 Electric discharges 3.1.3 Electroluminescence 3.1.4 Luminescence 3.1.5 Radioluminescence 3.1.6 Cathodoluminescence 3.1.7 Chemiluminescence 3.1.8 Thermoluminescence 3.2 Daylight 3.2.1 Sunlight 3.2.2 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 Luminous flux 3.4.2 Power demand 3.4.3 Luminous efficacy 3.4.4 Lumen maintenance 3.4.5 Life 3.4.6 Colour properties 3.4.7 Run-up time 3.4.8 Restrike time 3.4.9 Other factors 3.4.10 Summary of lamp characteristics 3.5 Flames 3.5.1 Candle 3.5.2 Oil 3.5.3 Gas 41 41 42 44 44 45 48 48 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 Final Lighting book artwork 08 25/3/09 10:04 Page 6 vii 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 Certification 4.3.2 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 Final Lighting book artwork 08 25/3/09 10:04 Page 7 viii 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 lighting 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 133 133 135 135 136 136 137 137 137 139 139 139 140 141 141 142 142 144 144 144 145 145 146 147 148 148 149 149 149 150 153 153 153 153 154 154 155 156 156 156 157 157 158 158 159 159 Final Lighting book artwork 08 25/3/09 10:04 Page 8 ix 9.3 Lighting recommendations 9.3.1 Illuminances 9.3.2 Light distribution 9.3.3 Maximum luminances 9.3.4 Discomfort glare control 9.3.5 Light source colour properties 9.4 Approaches to office lighting 9.4.1 Direct lighting 9.4.2 Indirect lighting 9.4.3 Direct/indirect lighting 9.4.4 Localised lighting 9.4.5 Supplementary task lighting 9.4.6 Cove lighting 9.4.7 Luminous ceilings 9.4.8 Daylight Chapter 10: Industrial lighting 10.1 Functions of lighting in industrial premises 10.2 Factors to be considered 10.2.1 Legislation and guidance 10.2.2 The environment 10.2.3 Daylight availability 10.2.4 Need for good colour vision 10.2.5 Obstruction 10.2.6 Directions of view 10.2.7 Access 10.2.8 Rotating machinery 10.2.9 Safety and emergency egress 10.3 Lighting recommendations 10.3.1 Control rooms 10.3.2 Storage 10.3.3 Ancillary areas 10.3.4 Speculative factory units 10.4 Approaches to industrial lighting 10.4.1 General lighting 10.4.2 Localised lighting 10.4.3 Local lighting 10.4.4 Visual inspection 10.4.5 Visual aids Chapter 11: Lighting for educational premises 11.1 Functions of lighting for educational premises 11.2 Factors to be considered 11.2.1 Students’ capabilities 11.2.2 Daylight or electric light 11.2.3 Common lines of sight 11.2.4 Flat or raked floor 11.2.5 Presence of visual aids 11.2.6 Surface finishes 162 162 164 165 166 167 168 168 169 170 170 171 171 172 172 173 173 173 174 174 175 175 176 177 177 177 177 178 180 181 182 182 182 183 183 183 184 185 185 185 186 186 186 186 186 Final Lighting book artwork 08 25/3/09 10:04 Page 9 [...]... to the next layer, the retina As the choroid approaches the front of the eye it separates from the sclera and forms the ciliary body This element produces the watery fluid that lies between the cornea and the lens, called the aqueous humor The aqueous humor provides oxygen and nutrients to the cornea and the lens, and takes away their waste products Elsewhere in the eye this is done by blood but on the. .. dominated by the rods It is the fovea that allows resolution of detail and other fine discriminations and the fovea is entirely inhabited by cones There are three other anatomical features that emphasise the importance of the fovea The first is the absence of blood vessels The second is that the collector and ganglion layers of the retina are pulled away over the fovea The third is the fact that the outer... simplest form of the relationship is quantified by the luminance coefficient The luminance coefficient is the ratio of the luminance of the surface to the illuminance incident on the surface and has units of candela/lumen The luminance coefficient of a given surface is dependent on the nature of the surface and the geometry between the lighting, surface and observer There are two other quantities commonly... many of the colour ordering systems For more detail on the Munsell system, other colour ordering systems and the relationships between them, see the SLL Lighting Guide 11: Surface reflectance and colour 15 Final Lighting book artwork 08 25/3/09 10:04 Page 30 Chapter Two: Vision Chapter 2: Vision 2.1 The structure of the visual system The visual system consists of the eye and brain working together Functionally,... about 24 mm The sphere is formed from three concentric layers The outermost layer, called the sclera, protects the contents of the eye and maintains its shape under pressure Over most of the eye’s surface, the sclera looks white but at the front of the eye the sclera bulges up and becomes transparent It is through this area, called the cornea, that light enters the eye The next layer is the vascular... by changing its shape The change in shape is achieved by contracting or relaxing the ciliary muscles For objects close to the eye, the lens is fattened For objects far away, the lens is flattened The space between the lens and the retina is filled with another transparent material, the jelly-like vitreous humor After passing though the vitreous humor, light reaches the retina, the location where light... through the eye, a transparent medium is necessary 17 Final Lighting book artwork 08 25/3/09 10:04 Page 32 Chapter Two: Vision As the ciliary body extends further away from the sclera, it becomes the iris The iris forms a circular opening, called the pupil, that admits light into the eye Pupil size varies with the amount of light reaching the retina but it is also influenced by the distance of the object... temperature While the CIE colourimetry system is the most exact means of quantifying colour, it is complex Therefore, the lighting industry has used the CIE colourimetry system to derive two single-number metrics to characterise the colour properties of light sources The metric used to characterise the colour appearance of the light emitted by a light source is the correlated colour temperature The basis of... Functionally, the visual system is an image-processing system that extracts specific aspects of the retinal image for interpretation by the brain 2.1.1 The visual field Humans have two eyes, mounted frontally Figure 2.1 shows the approximate extent of the visual field of the two eyes in humans, measured in degrees from the point of fixation The enclosed white area can be seen with both eyes The shaded area to the. .. chromaticity diagram is called the spectrum locus All pure colours, i.e those that consist of a single wavelength, lie on this curve The straight line joining the ends of the spectrum locus is the purple boundary and is the locus of the most saturated purples obtainable At the centre of the diagram is a point called the equal energy point, where a colourless surface will be located Close to the equal energy point . Lighting The SLL Lighting Handbook The Society of Light and Lighting The SLL Lighting Handbook The Society of Light and Lighting The SLL Lighting Handbook 222 Balham. getting into the fine detail of the Lighting Guides. The SLL Lighting Handbook is intended to be the first-stop for anyone seeking information on lighting.