Light Lines Jul/Aug 17

The Society of Light and Lighting

Part of the Chartered Institution of Building Services Engineers

STEP THIS WAY

The latest guidance on stairways

THE INTERNET OF THINGS

Could it compromise lighting?

Secretary

Brendan Keely MSLL bkeely@cibse.org

SLL Coordinator

Juliet Rennie

Tel: 020 8675 5211 jrennie@cibse.org

Editor

Jill Entwistle jillentwistle@yahoo.com

Communications committee: Gethyn Williams (chairman)

Rob Anderson

Iain Carlile MSLL

Jill Entwistle

Chris Fordham MSLL

Mark Ingram MSLL

Stewart Langdown MSLL

Linda Salamoun MSLL

Bruce Weil

All contributions are the responsibility of the author, and do not necessarily reflect the views of the society. All contributions are personal, except where attributed to an organisation represented by the author. Copy

‘We must not forget that first and foremost, a luminaire is exactly that –a device to illuminate our space,’ said incoming SLL president Richard Caple in his address at the AGM (The LED legacy, p5). Now that statement wouldn’t have been necessary 10 years ago.

The arrival of LEDs has not been so much a revolution as a revelation. In fact it has been a succession of revolutions. They not only changed the nature and potential of lighting itself but also radically shook up the lighting manufacturing industry.

As we all know, the advent of solid state lighting saw the electronics giants move in. Rooted in entirely different market spheres, they have little or no lighting hinterland. Coinciding with the drive to reduce energy, their agenda has been

William Wright, a former Master of the Worshipful Company of Lightmongers, died in May, after a battle with cancer.

performance and efficiency rather than lighting quality. The irony is that these changes came just at the point that the quality lighting message was beginning to get across.

Now we have the likes of Amazon and Google muscling in. LiFi is hovering on the edge of viability, and intelligent luminaires are already used for data collection, feeding back information on everything from who’s in the building and where, to guiding customers to the latest bargain in their preferred brand. In other words there is a danger that the luminaire’s primary purpose will be subsumed under the weight of the whizzier stuff it is now potentially capable of. Or as Caple rather more succinctly put it: ‘I would hate to see good lighting take second place to a good internet connection.’

John Aston pursues the same theme (Controlling interests, p12). Some of the functions demanded of today’s light fitting might govern which products or equipment are specified, or where the fitting is positioned, he argues, ‘and this is where a compromise with the primary lighting function might occur’.

Both agree that acquiring knowledge, and effectively disseminating it, is vital if good lighting is to be preserved. ‘The SLL provides a wealth of education and guidance on best practices,’ said Caple, ‘and we must continue banging the drum on quality lighting.’

Jill Entwistle jillentwistle@yahoo.com

1975, he first worked in the civil service, latterly for the National Gas Turbine Establishment as head of test services.

A chartered electrical engineer, Bill then moved to the John Lewis Partnership, holding a variety of roles over 25 years, including chief electrical engineer and corporate energy manager. In 2009, he started his own consultancy, Wright Energy and Environment. He lectured part-time at London South Bank University, and in recent years was the ECA's head of energy solutions. A fellow of the IET, Bill played a key role in the development of wiring regulations.

Bill began his career in the electrical industry in 1971, completing a student engineering apprenticeship sponsored by the MoD. Graduating from Cambridge University with an engineering degree in

'Bill will be remembered warmly by all who knew him for his generosity with his time and his invaluable knowledge and experience, which he was all too happy to share,' said the Lightmongers in its tribute.

Many thanks to all of you who came along to the society’s Awards, AGM and Presidential Address at the Royal Society in May. The place was full and a great evening had celebrating the great and the good of our industry. It’s only when someone delivers a citation for an award recipient that you get a fuller understanding of their life in lighting.

Listening to the citations being read for, among others, Joe Lynes, who was awarded an Honorary Fellowship, and Lou Bedocs, who received the President’s Medal, it’s quite humbling hearing the history of their lighting careers. These people have done so much for so many and were very worthy award recipients.

The annual report was also presented to the membership at the AGM and the finale of the evening was the society’s new president, Richard Caple, delivering his address (see p5). Congratulations to Richard, we look forward to working with him over the year, and many thanks to the immediate past president, Jeff Shaw, for steering the society so admirably.

We had a great time at the Sam Wanamaker Playhouse in June with the presentation Past and Future. The Jacobean counterpart to the Elizabethan Shakespeare’s Globe, the playhouse is extraordinary, a timber structure lit by candles yet still with a public licence. Clearly tricky drafting the risk assessment for that.

Speakers were Martin White, emeritus professor of theatre at the University of Bristol and historical consultant to the Royal Shakespeare Company, who with the theatre’s production manager, Paul Russell, gave a fascinating insight into theatre history and the painstaking process of lighting the playhouse authentically with candles. The future aspect of the presentation was covered by Paul Rudy, co-founder and senior

vice president of California-based Soraa Laser, who discussed and demonstrated a future light source that could replace LEDs. Thanks go to Peter Phillipson and the London events committee for organising the evening.

We’re looking forward to the 2017 Trotter Paterson Lecture with guest speaker Peter Boyce, technical editor of Lighting Research and Technology (LR&T) which will take place on 6 July. Peter will take a look at the way the industry has practised over the years, and how it has revolved around metrics, photometry, colorimetry and calculation methods to create spaces that encourage good visual performance without visual discomfort. These foundations are being questioned largely because of a greater understanding of the physiology of the eye and brain, and the widespread introduction of solid state lighting.

Peter will explore the nature of these questions, the reasoning behind them and suggest what the answers to the questions should be. It promises to be a very good evening. The LR&T Journal will celebrate its 50th anniversary in 2018 and we hope that many of you will join us at the Bishopsgate Institute for the lecture. This event is also organised by the London events committee. If you would like to get involved in the committee please do let me know.

The Night of Heritage Light returns in 2017 with the third event taking place on 29 September in Oxford. If you would like to get involved then again please do get in touch with us.

We’re heading back to Dubai to exhibit at Light Middle East from 17-19 October. After the success and enjoyment experienced last year we will deliver the second Ready Steady Light Middle East with Messe Frankfurt. We look forward to meeting our existing members and hopefully some new.

We are delighted to be publishing our latest Lighting Guide – LG16 Lighting for Stairs (see p10). This, along with all SLL and CIBSE guides and LR&T, is available for members to download from the Knowledge Portal. Another Lighting Guide, Transport Buildings,will also be available in the near future.

We’re now in the final stages of the subscription renewal process. Please do get in contact with us if you have any questions concerning the process or queries regarding membership benefits. Also, remember that we are here to discuss any queries relating to upgrading your membership.

industry must come to terms with the implications of evolving technology, says new SLL president Richard Caple

award winners found themselves in learned company

Art is key to great engineering, says new CIBSE president

Building services engineers should see themselves primarily as artists and practitioners, said the new president of CIBSE, Peter Y Wong (pictured right), in his inaugural address.

Speaking at the Royal Academy of Engineering in London, he drew a parallel between the artistic principles behind some of the world’s great masterpieces, and the principles that apply when creating high-performing buildings such as Hong Kong’s International Commerce Centre and Singapore’s Gardens by the Bay.

Exploring the core mission of CIBSE –to promote the science, art and practice of engineering – he argued that art

SLL invites BPA lighting entries

The SLL is now accepting entries for the Lighting for Building Performance category at the CIBSE Building Performance Awards 2018.

‘This award provides entrants with the opportunity to illustrate knowledge and innovation in lighting projects, pioneering new methods and delivering above-standard solutions, for clients and stakeholders alike,’ commented SLL secretary Brendan Keely.

Most recently won by Sainsbury’s

LIA tackles luminaire compliance problem

The Lighting Industry Association has launched a UK programme to carry out market surveillance on luminaires. It forms part of an EU-wide initiative from industry association LightingEurope.

The move is designed to to address the problem of compliance and exaggerated performance claims in the luminaire market. A 2016 survey found that 94 per cent of companies asked believed that the activity of their national market surveillance authority was insufficient to tackle the problem.

The industry-funded programme is being rolled out initially in the UK, France, Spain and Poland with others to follow.

Peter Hunt, COO of the LIA, was recently elected president of LightingEurope and is coordinating the scheme in the UK.

was the most important of those three ambitions, ‘because it is the structured and principled nature of the art of engineering that separates competent engineers from truly great engineers’.

Wong said that engineers should see their work as an expression of the principles of integrity, professionalism

Supermarket’s project Graphite LED lighting programme and Cundall Light4 for its own Birmingham office (pictured below right), past entries have shown a broad understanding of the impact that carefully designed lighting can have on a project.

Recognition is also given to projects that realise the importance of including a natural lightscape in the built environment, using energy efficient and carbon neutral methodologies.

The shortlisted entries will be announced at Build2Perform Live in November, and featured in the CIBSE Journal and SLL Newsletter. They will

On the lighter side...

Much has been written about the use of LEDs to encourage plant growth in the absence of daylight, but little has translated to the domestic sphere. But Barcelonabased design studio Goula Figuera, has now come up with Viride (Latin for green), a collection of experimental luminaires combining both plant and light source. There are three models, specially designed for each plant type, with one to three LED panels, programmed to turn on and off periodically to ensure each plant receives the most suitable amount of light.

Viride Dos has two differently orientated LED panels and a wide container that rotates perpetually at a very low speed. The even

and the public interest. They should be proud of creating buildings that perform well as a mark of their craftsmanship, he said, rather than for compliance or to meet minimum standards.

‘Building services engineers are one of the most important professions for the future health of the planet,’ he said. ‘The world is depending on what we do to ensure that we have healthy and productive places to live and work for generations.’

Peter Wong has more than 40 years’ experience as an engineer in the electrical and building services sectors. He is the first CIBSE president from the Hong Kong region, which he founded.

be showcased at the awards dinner in London on 6 February 2017.

Entry deadline is Friday 15 September 2017. For more details and entry form go to www.cibse.org/bpa-lighting-award

swankier Viride Tres, with an ultrasonic air humidifier, has three panels which rotate continuously at a very low speed in an uninterrupted movement that evokes the path of the sun as seen from earth, from sunrise to twilight. Long way from the dusty aspidistra.

www.goulafiguera.com/works/viride/

The LED legacy

The lighting profession must come to terms with the

many

implications of evolving technology, argued incoming SLL president Richard Caple in his AGM address

The fallout of the LED revolution was a key theme in incoming president Richard Caple’s address. Acknowledging the radical change that the lighting industry has undergone over the past decade, Richard Caple said that it had left ‘a legacy of misunderstanding’ about LEDs.

‘I think it is recognised by most that the LED revolution is over, but I still think...that when it comes to this technology, greater clarity is needed from manufacturers and suppliers, as well as improved standardisation. I still feel there is a knowledge gap between end users and professionals.’

Although he was fascinated by the degree to which the industry had so quickly become technical and involved, he also had concerns, Caple said. ‘If we compare a modern luminaire today with one of 10 years ago, the two are very different animals. They are different because not only do today’s luminaires provide light, but they are also a platform for other embodied technologies, such as Wi-Fi, Li-Fi, Bluetooth, and sensors that can monitor CO2, temperature, humidity and so on.

‘While I am not suggesting that this is necessarily a bad thing, I think crucially we must not forget that first and foremost, a luminaire is exactly that – a device to illuminate our space.’ While it was essential to embrace new technologies and an ever greater connected world, Caple argued that the lighting industry must never forget that quality lighting is fundamental to people’s health and wellbeing. ‘I would hate to see good lighting take second place to a good internet connection,’ he said.

He also expressed concern that far too much emphasis was placed on the energy-saving potential of LED technology. ‘While this is, of course, extremely important, not least from an environmental perspective, it is just one factor in the overall consideration. I see whole projects being based on energy, CO2 and maintenance savings with not a single lighting calculation being made to check that the proposed replacement will meet the requirements of the space and its users.’ He said that ‘return on investment and paybacks seems to rule over all else’.

‘As Iain Macrae discusses in his article in the last Newsletter [May/June 2017], staff costs far outweigh any capital or maintenance costs for a building. If the new lighting is not fit for purpose and fails to meet the basics such as light levels, uniformity, colour performance, and compliance with glare and

luminance, then the “investment” may end up not being so wise.’

On both counts the society, which he noted was growing, with a current membership of more than 3500 worldwide, had a strong role to play. ‘The SLL provides a wealth of education and guidance on best practices, and we must continue banging the drum on quality lighting,’ he said.

‘I would hate to see good lighting take second place to a good internet connection’

Caple also raised the uncertainty which hung over areas such as the relationship between lighting and wellbeing. ‘Humancentric lighting, or however you wish to term it, seems to be the current in-vogue topic. While it is generally acknowledged that changes in the colour and intensity of lighting can affect our mood, wellbeing, alertness and productivity, I feel it is still unclear how we actually apply this,’ he said. ‘Do the needs change if you are working in an office compared to a hospital?’ Ultimately much more independent research was needed, he said, ‘and, importantly I think, we must never forget that there is no substitute for daylight.’ He said that the SLL was working on a position paper around this topic, which was scheduled for publication later this year.

There was, of course, a wider uncertainty stemming from Brexit, continued Caple, an issue about which he would be

Richard Caple: ‘There is still a knowledge gap’ t

Photography: Michael Eleftheriades

‘very mindful’ throughout his year as president. ‘Our industry faces a number of challenges in the future. Our government has recently invoked Article 50 and started the countdown to the UK leaving the EU. No one knows yet what this means for any of us, let alone the impact it may have on our industry, and for many who do business throughout Europe it will no doubt be an anxious time.

‘From an industry perspective,’ he continued, ‘we need to make sure that our voice continues to be heard to ensure we are best placed to deal with whatever the outcome is. Through working with other organisations and bodies the SLL can play its part in helping.’

Caple also declared his intention to pursue the same aims as his predecessor Jeff Shaw in promoting lighting as a profession. ‘The question has to be asked,’ he said. ‘Why shouldn’t lighting be a more obvious career choice and why isn’t it? As a key part of my year as president I wish to continue the work that Jeff has done by promoting lighting as a career and a profession. I therefore look to inspire through working with Stem, but also wish to engage with a slightly older age group, those in higher education as well as young engineers already in the building services industry.’

In the course of his year, he hoped that the SLL could publish a career pathway document, said Caple, which would help those seeking or considering a career in lighting to see what options, routes and qualifications are available to them.

He cited his own somewhat serendipitous route into the profession after he left college some 18 years ago. Caple studied design technology and graphic design at A Level and subsequently joined Thorlux Lighting as a trainee lighting

design engineer. ‘At the time, of course, I didn’t have a clue what one of these was,’ he said. ‘Unbeknown to me at the time, my lighting career had started.’

Caple undertook all of the LIF courses – ‘taking a particular interest in the photometry and testing, something that would later define my role in Thorlux’ – completed the LET Diploma, the SLL Lighting Diploma, and finally the Lighting MSc at the Bartlett in 2012. His own experience had informed his firm belief in the importance of education, he said. ‘My passion is not only to design high-quality, energy-efficient lighting solutions, but to educate, train and provide best practice guidance in our changing and fast-moving market.’

Again the society was instrumental in this, he said, and events such as Ready Steady Light, the Masterclass series, Young Lighter of the Year, industry trade shows, and many regional events were invaluable in this respect.

The award-winning Night of Heritage Light and its successor, NoHL2 in York, had been particularly successful exercises, said Caple. ‘Both have raised the profile of not just the SLL, but our industry as a whole; we have captured people’s imagination and helped inspire those normally outside of the industry to become involved.’ Keen to continue the momentum, Caple said that Night of Heritage Light 3 was in the pipeline.

In summary, he said that his main aim for the year was to promote lighting both as a career and a profession. ‘I hope that I can inspire more people to pursue lighting as a career choice. I think one of the great things about our industry is how diverse it is, from lighting designers to product designers, from electrical engineers to mechanical engineers,’ concluded Caple. ‘Our industry never stands still.’

Caple will promote lighting as a profession: ‘Why shouldn’t lighting be a more obvious career choice and why isn’t it?

Pillars of society

This year’s award winners found themselves in learned company

The very first ‘learned society’ meeting was held on 28 November 1660 following a lecture at Gresham College given by Sir Christopher Wren. Not, clearly, the beginnings of this society, but the venerable institution that hosted this year’s SLL AGM and Awards, the Royal Society in London’s St James’s, home of scientific luminaries from Darwin to Dawkins.

The President’s Medal, awarded for a lifetime contribution to lighting, this year went to Lou Bedocs. In his citation, Iain Maclean traced the extraordinary life story of Bedocs. Born in Hungary, he eventually came to the UK as a refugee following the Soviet invasion. He was befriended by one of the refugee camp carers who invited him to stay with his family in Malvern.

First employed at the Ferguson radio factory, he recognised that television was the future and asked to move to the Ferguson TV factory in Enfield, which became part of Thorn Electrical Industries. Enrolled as an apprentice, he worked in the various departments of Atlas Lighting, also owned by Thorn.

After completing his apprenticeship and engineering studies at various polytechnics he took on the role of environmental development engineer in the Atlas Lighting labs, where he would go on to develop many novel lamps, lighting products and application techniques, including the development of air-handling luminaires and paving the way for intelligent fittings. He also devised methods for calculating crosstalk attenuation between rooms, enabling ceilings with recessed troffers. The results of this research led to the early use of full building services integration, where heat, light and sound were brought together within the total design process.

Thorn Lighting was formed in 1969 by the joining together of the Atlas, Ekco and Mazda brands, and Bedocs expanded his research into glare, emergency lighting and flicker. He was also involved in the concept, design and technical fit-out of a new multi-floor dedicated research building in Enfield, a leading national lighting research facility. During the next 30 years he was to fill increasingly senior managerial roles in Thorn finally becoming its technical director in 1991.

His extensive R&D work led to him becoming involved in UK and international standards development, particularly in emergency lighting and calorimetry. Bedocs has been an active member of more than 26 different CIE committees and panels, including as chair and director. He was elected a Fellow of the IES in 1975 and Fellow of CIBSE in 1977.

A vice president of CIBSE for three years, he was chair of the SLL in 1990 and chaired the SLL technical committee for more than five years. During those years, he was awarded two Leon

Lou Bedocs receives the President’s Medal from Jeff Shaw

Joe Lynes was made an Honorary Fellow

Iain Macrae was given the Lighting Award

Dan Lister was the recipient of the Regional Award t

Photography: Michael Eleftheriades

t Gaster Awards, as well as receiving the SLL Lighting Award. He was made honorary president of the LIF in 2010.

He has trained many lighting engineers through his innumerable lectures and conference presentations and has been a frequent visiting lecturer to several universities and a lecturer for the Mid-Career College. ‘It has been a privilege to have known, worked with and learned from him during my time in the lighting industry,’ said Maclean in his citation. ‘There are few others who have contributed so much to our understanding of and the use of light in all of its many aspects and he is a worthy recipient of the society’s President’s Medal.’

One of the surprising things about the award of an Honorary Fellowship to Joe Lynes ‘is not that Joe is getting it, but that he hasn’t received it a long time ago,’ said Paul Littlefair in his citation. ‘For well over 50 years he has been at the forefront of lighting in the UK.’

Lynes started in the photometry department at Falk Stadelmann and then moved to AEI, where he wrote his first paper on the calculation of interreflected light. He began his long association with daylight at Pilkingtons, producing sunpath diagrams and the famous pepperpot diagrams for daylight factor calculation. This interest in mathematical projections was to lead to research in subjects as diverse as perspective in Florentine art and the design of sundials. During a spell at the University of Manchester he wrote Principles of Natural Lighting, ‘still one of the great textbooks on daylighting’.

He continued his work on daylighting at Plymouth Polytechnic. His influential 1979 paper, A Sequence for Daylighting Design, introduced the concepts of average daylight factor, room depth criterion and no sky line, still widely used. ‘By developing a daylight calculation process that designers and planners could actually understand, Joe has had a major impact on daylight provision in buildings, especially housing,’ said Littlefair.

In 1979 he joined the Thorn Lighting research team. His other great interest was photometry, which led to his developing a wide range of innovative concepts: vector illumination and the flow of light, the luminaire domain, and the idea of discomfort glare as visual distraction. ‘Ideas that many people are just discovering today, like cylindrical illuminance, were topics Joe was writing papers on 30-40 years ago,’ said Littlefair. In the 1970s, he also predicted the current criticisms of the CIE colour rendering index, and recommended colour gamut, a measure being adopted for the new colour-enhancing LEDs.

After Thorn, Lynes returned to academia at Hull School of Architecture. ‘One of the endearing aspects of his work with students is that it has encouraged Joe to develop simple, virtually zero cost lab kit: the matchbox sundial, the grease spot photometer for illumination vector, and the Thorn contrast rendering meter, which was essentially pencil circles on a series of grey backgrounds.’ At the other end of the scale, in the days before the internet when e-learning was unknown, Lynes and Mike Marsden set up Hyperlight, a unique computer-based lighting teaching tool, which introduced many of the techniques now used on commercial websites.

During his long and active retirement, Lynes, a Quaker for many years, has been involved in the peace movement. ‘While the rest of us might have been gardening and pottering along to the odd SLL meeting, Joe has been escorting Palestinian schoolchildren through military checkpoints in the occupied West Bank,’ said Littlefair.

Prof Kevin Kelly gives the Leon Gaster to Prof John Mardaljevic

Prof Arnold Wilkins receives the Walsh Weston Award

Vice president Iain Carlile with LET prize winner Ben Poulton

Prof Kevin Kelly, Barrie Wilde and Joe Lynes

‘Ideas

that many people are just discovering today, like cylindrical illuminance, were topics Joe was writing papers on 30-40 years ago’ – Paul Littlefair

‘It gives me particular pleasure to provide this citation because Joe more than anybody else has influenced and inspired me in my own lighting career,’ he continued. ‘He has been very generous both in ideas and encouragement.’

Iain Macrae was this year’s recipient of the Lighting Award. He studied mechanical engineering at Hatfield Polytechnic before joining Thorn Lighting as a product designer at Spennymore. After three years he took on responsibility for lighting design as well as the management of custom products, a role he would continue with for the next 11 years.

It was during this time that he became involved in the SLL, serving on the technical and publications committee and chairing the LG5 working group. He was also active in both BSI and CEN. It was around this time that he first met Mike Simpson who gave the citation. ‘We were both founding members of the Masterclasses and Iain immediately struck me as someone who not only had a deep knowledge of lighting but also had a very easy way of presenting it.’

In 2009 he became head of global lighting applications for what was by then the Zumtobel group, and in 2012 he became president of the SLL. He is currently applications director for Wila Lighting. ‘The society’s award is given to the person who has made an ongoing commitment to lighting and to the society, ‘said Simpson. ‘I cannot think of a more worthy recipient.’

Winner of this year’s Regional Award was Dan Lister of Arup, one of the four key organisers behind NoHL in 2015 and the main organiser of last year’s follow up NoHL2 in York. The aim was to engage with all educational key stages and introduce a variety of young people to light and lighting, to let them experiment with light and ultimately to realise their ideas at a public event.

‘His determination, alongside very considerable time and effort, ensured that the society delivered the four designs for the fivenight festival, much to the delight of the students and teachers alike, not to mention the thousands of visitors,’ said Liz Peck in her citation. ‘Dan’s dedication to – virtually single-handedly – mastermind this contribution to illuminating York and see it through to fruition was a credit to the students and schools, to the society and to himself.’

The awards for best papers published in LR&T last year were both presented by Professor Kevin Kelly. The Leon Gaster Award went to Professor John Mardaljevic and N Roy for The Sunlight Beam Index (LR&T, 2016; 48(1): 55-69). The Walsh Weston Award was given to Professor Arnold Wilkins for A Physiological Basis for Visual Discomfort: application in lighting design (LR&T, 2016; 48(1); 44-54).

LET Student Prizes were given to Simon Blyth, Nicola Parker and Ben Poulton. Chris Wilkes of Holophane, Lou Bedocs of Thorn, Jamie Yates of Trilux and Roger Sexton of Xicato were also presented with Sponsors in Partnership Certificates.

Jonathan West, Maz Mullane and Laurie Socker

Mike Simpson, Alexandra Kalimeri and Dr Kevin Mansfield

Nicola Parker and Sonia Pepperell

Simon Fisher, Jonathan Rush, Vy Pettit and Rob Anderson

A step by step guide

Paul Ruffles outlines the society’s new LG16 which focuses on lighting stairways – from the strictly functional to flights of fancy

Probably your first thought on seeing this article was, ‘why a whole lighting guide just for stairs?’ Good point, and I should say it did start out as just a Factfile. This was needed because we realised that Standard BS EN 12464, while giving recommended lighting levels for various types of stairs, didn’t say where these levels were to be calculated or measured. This, of course, applied equally to our own Code for Lighting as it used the identical levels from the standards. The problem was that every time I presented a draft Factfile to the technical publications committee, someone would say ‘yes, but what about ramps?’, ‘…refuge areas?’, ‘…emergency lighting?’, ‘…escalators?’ and so on.

So, we now have a 20-page Lighting Guide on lighting for stairs full of recommendations for safe locations for luminaires, positioning to allow safe access for maintenance, exit signage locations and, of course, where to calculate and measure lighting levels on the staircases.

In most buildings there are two types of stairway: those used constantly by the occupants to pass up and down the building, normally referred to as accommodation stairs, and the escape stairs that are rarely used except to evacuate the building. The main or accommodation stairways can vary from being simply decorated and lit, as in a typical hospital or factory, to more lavishly decorated and feature lit in some more upmarket shops, offices and hotels. The escape stairs are often left undecorated and lit in a very functional and simple way.

Both sorts of staircase will need an emergency lighting system to provide illumination in the event of a failure of the normal power supply. This emergency lighting system prevents falls when the main lighting goes off, and is there to provide lighting to the stairs and landings to enable safe evacuation of people from the building if needed.

Lights are often positioned at each landing, as this ensures that the top and bottom of the flights of steps are easily lit. The landing also provides a flat platform to erect step-ladders or other access equipment for cleaning and maintenance.

The average maintained lighting level on the main landings should be the same as the recommended lighting level for the stairway – the normal criteria for uniformity apply. In general, the lighting should be as even as possible with no sharp changes of light level. No shadows should occur across the landings, as this may be misinterpreted as a step.

It is important to light well small quarter landings where a stair turns so that users can accurately judge the stop of one flight and the start of the next. It is also important to light well any ‘rest’ landings that are used to break up long continuous flights

into shorter sections. This ensures that users can see that what might appear to be one very long flight suddenly has a much wider ‘step’, that is in fact a landing, to allow users to pause safely if they cannot make the whole long flight in one go.

Luminaires must not be positioned such that they reduce the width of the stairs, as this might infringe local building regulations on minimum widths. They should also not be placed in locations where they could be hit by the body or head of those passing up or down the stair or crossing landings. If at all possible, they should not be positioned above the stair flights themselves, as access for maintenance is difficult and access equipment may compromise the use of the stairs. Luminaires should also not be positioned on landings directly above doors that open on to the landing, as there is a risk of impact on any access equipment being used, and again such equipment may impede people’s escape.

Refuge areas, where wheelchair users and those with

DPA Lighting worked with Eva Jiricna Architects to light the Tiffany Gallery at the redesigned Luce Center at the New-York Historical Society Museum and Library. The centrepiece staircase is lit with cool-white, integrated linear LED fittings

Photography: Corrado Serra

mobility problems can wait for assistance in an emergency, are normally located to one side of the main landings. These areas need to be well lit to aid transfer from the wheelchair to a stair lift for transport down the stairs. If a stair-chair is permanently located in or adjacent to the refuge area, normally wall mounted, it will need to be well lit to aid location, removal and assembly. Good vertical illumination will be needed on any information signs and any intercom system that are located in or adjacent to the refuge area. Emergency lighting must also be located in these areas to illuminate all key signs, intercoms and physical features: the BS 5266-1 recommendation is for five lux horizontal on the floor and five lux vertical on signs and communications equipment.

Controls

Placing switches on the stairway itself leads to the danger of the lights being turned off while people are using it or lights being left on permanently. If switches are ever used, they need to be located at every door into the stairway to avoid people entering a dark staircase at levels where there is no switch. Because of these problems, it is normal that the lighting of staircases in most public, civic and commercial buildings is centrally switched under management control. This means that the staircase lighting is on whenever the building is occupied. In well-used staircases this is sensible, assuming

‘The main stairways can vary from being simply decorated and lit, as in a typical hospital or factory, to more lavishly decorated and feature lit in more upmarket shops, offices and hotels’

that the lighting uses the minimum energy necessary to provide the required level. Where staircases are only occasionally used then there are other control systems that can be considered as a way of saving energy.

Presence detectors can be used to bring on the lighting on flights of stairs whenever movement is detected by someone entering on to a landing or moving up or down the flight. The detectors must be sited such that they can be triggered by someone moving on any part of any flight of stairs within a staircase. Remember a person with angina or similar medical problem, may have paused part way up a flight to catch their breath. Detectors need to be linked to the luminaires such that either any detector will bring on the whole stair lighting system (preferred), or a single detector on a landing will bring on the lighting for the whole of the flight and landing above and below. People do not like walking up or down into darkness even if where they are is illuminated.

Push-button timers are still used in many multi-occupancy buildings. These are manually operated by users at the doors into a flight of stairs and keep the lights on for a set period. A push-button point should be provided on each landing where

there is access to the staircase. The timers should be set to allow an elderly or infirm person sufficient time to climb up from one landing with a push-button to the next – this should not be less than two minutes. It is recommended that in any staircase where timers are used there is a permanent residual background lighting level of not less than one lux to ensure a minimum level of safety. This can be provided by making the emergency lighting maintained, so that it is on always, or by providing a separate circuit up the staircase operating small lights that remain permanently on.

Lighting Guide (LG)16: Lighting for Stairs by Paul Ruffles is now available. Go to www.cibse.org/knowledge (PDF version free for members)

Positioning fittings near the top and bottom of a flight better lights the top and bottom couple of steps so that people can get the rhythm of the steps. A movement detector at top and bottom will trigger both lights from whichever direction someone approaches

Image courtesy of Franklite

Controlling interests

The Internet of Things offers undeniable opportunities. But could it compromise the primary function of a lighting system? asks John Aston

The 21st century has brought three major challenges to the lighting industry. At the turn of the century we first learnt about the non-visual effects of lighting and the third receptor in the eye. Next came solid state lighting – or LEDs, as we know them today – and now we have to contend with the ‘Internet of Things’. All of these subjects present our industry with threats and opportunities, new ways of doing things and a need to understand their impact.

In the last issue (May/June 2017), Inessa Demidova provided a thought-provoking and informative article on light and circadian ryhthms. LEDs are now capable of meeting most lighting application needs, and enough has been said about these for now. So what do we need to think about with regard to IoT?

The first, and obvious, question to ask is: what is the Internet of Things? We are all familiar with the internet and the World Wide Web; we use them to communicate, promote, seek information and shop. And we tend to think of the internet as something that connects our computers, smart phones and, more recently, control devices and sensors. These last items are taking us into the realm of connected things; hence the IoT.

However, the idea of connected things may have a far-reaching impact on the lighting industry simply because we now use LEDs as a light source.

To understand why this might be, it is useful to have a look at how we have developed lighting and control systems for the non-domestic built environment in the past 30 years or so. The lighting controls industry can now offer building-wide, networked systems that can address each light and sensor individually, with luminaire designs now integrating much of the intelligence into their electronics. The result of this development work has been the introduction of a network that penetrates almost every part of a modern building; a fact not lost on those looking to manage other building services or interested in data collection.

The lighting system is now being seen as able to provide the infrastructure for a building-wide, multi-function network with the potential to offer more than a lit environment. The introduction of LED technology has added to the attraction of this network because it is possible to use an LED to transmit data reliably and at very high speeds. This raises our second question: can the IoT compromise the primary function of a lighting system?

Our historic approach to lighting design has been to provide the right light, in the right place and at the right time. Of course there have been changes in the way we do this; debates continue as to the appropriateness of metrics and how we apply them, discussion as to the quantity and quality of light that should be provided in any given situation. We do not pretend that we know all the answers, or that this is an exact science; we do, though, strive to deliver the best solution based on available knowledge and equipment.

‘These functions might require the building designer to specify particular products. This is where a compromise with the primary lighting function might occur’

The object of a lighting system is the provision of a comfortable, effective and efficient environment for people, whatever the application might be. These criteria should be the sole determinant of the choice and location of the lighting equipment in any application. If the intention is to include the IoT in a lighting installation – as a specified requirement for a project – there is a chance that the choice and location of lighting equipment might be dictated by other priorities.

It is possible to consider the introduction of the IoT to lighting as just another step in the progress of control systems, only now using the internet model and allowing the interaction of personal devices (for example, smart phones) with the lighting. The use of familiar protocols such as Dali, DMX, KNX, Zigbee and others would still be possible because the whole ethos of the internet concept is the ability to link networks.

TCP (as in TCP/IP) is an abbreviation for transmission control protocol and it is the basic communication language of the internet; through gateways it facilitates all the device connections we are familiar with today. On its own, then, IoT might facilitate and develop the abilities of lighting controls to be more personal, more able to adopt new strategies and all at a lower cost with, potentially, better user interfaces. The potential ‘trouble’ for the lighting world comes when the attractions of this pervasive network are recognised.

Just as it allows the inclusion of lighting controls protocols so IoT also permits the connection of BACNET and other BMS and building services systems’ communications. It simplifies the business of interconnection and even interoperability, often without compromising the original abilities of the separate systems. Even extending the links to other building services –often already done – is not a threat to lighting.

The potential problem comes when there is a desire to go further into ‘location-based services’ and the gathering of ‘enterprise data’. The ability of LEDs to carry information as well as to deliver light offers businesses the opportunity to guide people around buildings or download location-specific data. Shoppers can be alerted to special offers nearby, and so on. At the same time sensors and other links might tell businesses about movement patterns, numbers present or where specific

individuals are located. Some of these functions might, conceivably, require the building designer to specify particular products or equipment, and this is where a compromise with the primary lighting function might occur. Or, maybe, the optimum position for a light fitting to meet the wider purpose is not the ideal place for the lighting designer.

The wider abilities and potential of lighting explains the interest of the likes of Apple, Amazon, Cisco and others, informing their acquisition strategies and partnerships, which is where a wider risk to the lighting industry lies. Established lighting businesses might vanish into the modern internetbased global behemoths, and lose the passion and knowledge we have built over the past 100 years and more. Or we could decide to inform ourselves about all the issues surrounding the IoT and ensure our survival by demonstrating better knowledge and skills in the implementation of lighting systems that are demanded by our customers. Like most disruptive technologies IoT will be both a threat and an opportunity; we can only make it the latter by understanding all the issues surrounding the changes in technology. We have, largely, successfully adapted to the LED revolution and survived in a market where some would say business has been better than ever. We should be able to continue in this vein.

Taking a concluding paragraph from a previous article, about smart lighting, we can look forward with optimism if we learn new things, employ the right people and maintain our influence.

‘In the longer term the whole lighting industry has an opportunity to be involved in developing lighting systems that become an essential part of a business enterprise, forming a core service network that creates useful data, links systems and delivers greater comfort, productivity and efficiency. We live in exciting times but let’s not be carried away by hype and always be mindful that technology is our servant and not our master; nor is it to be used just because it is there. We may have already opened Pandora’s Box but we must keep our eye on the benefits that can be derived from good lighting, and make sure that all the other features, as well as those new entrants to the lighting industry, do not forget its purpose and its value to our wellbeing.’

‘We could decide to inform ourselves about all the issues surrounding the IoT and ensure our survival by demonstrating better knowledge and skills in the implementation of lighting’

I have deliberately avoided more technical content in favour of raising the major issues, and specifically an issue raised by Richard Caple, in his inaugural presidential speech (see p5). Perhaps others would like to pick up the challenge to present more detailed appraisals of IoT technology, both its future possibilities and pitfalls?

Primary source

Iain Carlile selects four of the latest LR&T papers to be published online, which all focus on various aspects of white light LEDs

Four of the most recently published papers look at the application of white light LEDs from a range of perspectives: with respect to glare, artwork conservation, life-cycle assessment and the relationship between CRI and luminous efficacy.

On the subject of glare, Huang et al’s paper describes an experiment investigating discomfort glare caused by differing spectral power distributions (SPD) in white LEDs. Two sets of experiments were conducted, the first to investigate the effect of LEDs with the same perceived appearance, but having a different SPD (metamerism), and the second the effect of varying the correlated colour temperature (CCT).

It was found from the metamerism investigation that 7000K light sources constructed from varying blue LEDs combined with consistent red and green LEDs resulted in similar glare perception between the different sources. In the CCT investigation light sources between 3000K and 7000K, with 1000K increments, were used. It was found that there was a significant difference in glare perception between the varying CCT values, with higher CCT values producing higher perceived glare.

Examining the conservation of artworks, specifically traditional heavy colour Chinese paintings, Dang et al investigated optimising the white LED spectrum to minimise damage to the painting. The authors used narrowband spectra LED light sources to illuminate the paintings and measured the CIELAB colour data at periodic intervals. From this data, decay curves were constructed according to the different pigments used in the artworks. From an analysis of the data, both quantitative and relative influence coefficients were determined for each narrowband light type. The authors make recommendations for different spectral irradiance distributions for lighting different types of Chinese paintings, including fine brushwork with rich and deep pigments, heavy colour golden paintings, and artworks with strong green heavy colours.

Casamator et al looked at the total life cycle of LED lighting, conducting cradle-to-grave assessments with the aim of informing the ‘eco’ design of new LED lighting products. Using a novel assessment method more suited to LEDs than traditional sources, the study considered all elements in the life cycle, excluding maintenance and packaging manufacture. Different scenarios were considered at different useful lives (1000, 15,000 and 40,000 hours) and different end-of-life options (domestic refuse and recycling centre).

The authors found that new ‘eco’ lighting products had 60 per cent less environmental impact in all scenarios when compared with existing lighting products. It was found that the life-cycle stages with the biggest impact were (largest first): use, followed by manufacturing, then end of life and, lastly, transport. Clearly from this analysis the energy in use has the biggest impact and strategies to reduce this will yield the greatest savings over time. Zhou et al examined the trade-off between the CRI and

Optimising the white LED spectrum to minimise damage to Chinese traditional heavy colour paintings (Dang et al)

luminous efficacy of a white light chip-on-board (COB) LED. The authors found that adding red phosphor (655nm) into the phosphor layer of a COB LED can broaden the emission spectrum, significantly improving the CRI of the LED light source, while not greatly compromising the luminous efficacy.

Iain Carlile, MSLL, is an associate of DPA Lighting

Lighting Research and Technology: OnlineFirst

In advance of being published in the print version of Lighting Research and Technology (LR&T), all papers accepted for publishing are available online. SLL members can gain access to these papers via the SLL website.

Discomfort glare caused by white LEDs having different spectral power distributions

WJ Huang, Y Yang and M Ronnier Luo

White LED spectrum for minimising damage to Chinese traditional heavy colour paintings

R Dang, Y Yuan, G Liu, C Luo and J Liu

Comparative life-cycle assessment of LED lighting products

JL Casamayor, D Su and Z Ren

LED chip-on-board package with high colour rendering index and high luminous efficacy

Z Zhou, H Wang, J Zhang, J Su and P Ge

City lights

2008 YLOTY winner Vasiliki Malakasi recounts how her research radically altered her career path

The Young Lighter of the Year competition in 2008 was an opportunity to present to a wider lighting audience the findings of my MSc thesis on urban lighting and luminance patterns along Glasgow’s riverfront.

In a nutshell, my research examined how materials and material reflectance affected the perceived brightness and levels of comfort in a pedestrian urban setting after dark. Following the YLOTY presentation, the research was published in a book including other urban papers (University of Lausanne, Presses Polytechniques et Universitaires Romandes, October 2009).

Looking back, it was the notion of lighting being able to transform architecture in an urban context that introduced me to the lighting world. In 2004, I was on my final year studying architecture at the Glasgow School of Art. As part of my thesis I was researching ways to enliven a cultural centre at night when, through an acquaintance studying at UCL, I came across papers and specialist studies on the benefits of urban lighting. I was fascinated.

What started as an area of interest for my thesis project, soon became an academic pursuit and gave me a new professional direction. Following graduation, I joined the MSc in Light and Lighting postgraduate course at UCL. I never thought of deviating from conventional architecture, especially since it’s such a long course and I was eager to practise, but in 2006, shortly after receiving my masters, I joined Arup Lighting in London. I suppose after that I did not look back. It soon became apparent that I was doing better service to architecture through lighting design. I was contributing to the night-time architecture –how new and inspiring was that?

I stayed at Arup for seven years and I was lucky to be part of such a great team. I learned a lot from my colleagues and I was encouraged through internal Arup funds to further my research on urban lighting – such opportunities are rarely given outside academia. In 2011, together with a colleague, we presented the findings of our paper, Lighting in the Urban Age, at the PLDC in Madrid. The paper related to my MSc research, but it was further enriched with research facts and actual project examples.

While at Arup I worked on some key national and international projects (Tate Modern Extension, Acropolis Museum, Dublin Airport T2) and had the chance to collaborate with well-known architectural practices (Herzog and de Meuron, Renzo Piano, Zaha Hadid Architects, Bernard Tschumi Architects). Some projects gave me the opportunity to put my urban lighting theories into practice and this experience was invaluable.

In 2013, I started my own consultancy, Idea Design, based

in London. My work included a variety of projects in and out of the UK. Lighting design aside, the past few years I have been involved with The Rothschild Foundation as a lighting advisor, and the IALD, where I am serving the membership committee for a second term. In June this year I became part of the GIA Equation lighting team in London and I am looking forward to this new and exciting professional challenge.

Urban lighting started as an academic pursuit, but somehow the essence of my initial research followed me through. As Idea Design, I joined a team shortlisted at the Urban Lightscape Competition for the EUR District in Rome during PLDC 2015. Last summer Idea Design, together with Erect Architects and other collaborators, won second place at the Loughborough Junction Masterplan competition in South London. I would like to think it’s not all a coincidence. Hopefully other such opportunities to work on an urban scale will come in the near future.

One needs to be careful on the choice of their academic research topic; it often has a life of its own. Sometimes it can even inform your career path. I am glad my research was on urban lighting, something I am passionate about. The Young Lighter of the Year competition gave me a platform to verbalise and share this passion with my peers, but most important, it made me aware this was a topic I wanted to actively pursue.

Malin and Goetz, Covent Garden, London, lighting by Idea Design

Photography: Dirk Lindner

2017

6 July

Trotter Paterson Lecture: Lighting in Flux (Organised by the SLL)

Speaker: Peter Boyce

Venue: Bishopsgate Institute, EC2 www.sll.org.uk

12 July

Lighting: more psychology and art than science? (CIBSE South West Region)

Speaker: Henrik Clausen, director of Fagerhult’s Lighting Academy

Venue: Arup Auditorium, Bristol bonnie.brooks@sdsolution.co.uk

24 July

How building services engineers can save civilisation (CIBSE Yorkshire Region)

Speaker: Fiona Cousins, Arup Venue: Arup, Leeds www.cibse.org/training-events

5-7 September

Shanghai International Lighting Fair

Venue: Shanghai New International Expo Centre (SNIEC) http://shanghai-international-lighting-fair. hk.messefrankfurt.com/

11-12 September

Museum Lighting Symposium (Organised by SEAHA and the SLL)

Venue: UCL, London WC1 https://museumlightingconference.com

11-15 September

Exterior Lighting Diploma Module 1 (Organised by the ILP)

Venue: Draycote Hotel, Rugby dip@theilp.org.uk

26-28 September

Smart Lighting Forum and Show

Venue: Bregenz Festspielhaus Bregenz, Austria www.trends.lighting

28 September

How to be Brilliant

(Organised by the ILP)

Venue: Marshalls Design Space, EC1 jess@theilp.org.uk

29 September

Night of Heritage Light 3

Location: Oxford www.sll.org.uk

9 October

Exterior Lighting Diploma Module 2 (Organised by the ILP)

Venue: Draycote Hotel, Rugby dip@theilp.org.uk

6 July:

17-19 October

Light Middle East (with SLL Ready Steady Light)

Venue: Dubai International Convention and Exhibition Centre www.lightme.net

19 October

How to be Brilliant (Organised by the ILP)

Venue: Marshalls Design Space, EC1 jess@theilp.org.uk

27-30 October

Hong Kong International Lighting Fair

Venue: Hong Kong Convention and Exhibition Centre www.hktdc.com

1 November

Fundamental Lighting Course (Organised by the ILP)

Venue: Regent House,Rugby jo@theilp.org.uk

1-4 November

Professional Lighting Design Convention

Venue: Palais des Congrès de Paris http://pld-c.com

7-10 November

Interlight Moscow

Venue: IEC Expo Centre, Moscow https://interlight-moscow. ru.messefrankfurt.com/

15-16 November

LuxLive 2017

Venue: London ExCeL http://luxlive.co.uk

16 November

Lux Awards 2017

Venue: InterContinental London – The O2 http://luxawards.co.uk

Lighting Masterclasses: Masterclass: The Lighting Knowledge Series is kindly sponsored by Holophane, Thorn, Trilux and Xicato. For venues and booking details: www.sll.org.uk

LET Diploma: advanced qualification by distance learning. Details from www.lightingeducationtrust.org or email LET@cibse.org

CIBSE Training: various courses across the whole spectrum of lighting and at sites across the UK. Full details at www.cibse. org/training-events/cibse-cpd-training

LIA courses: details from Sarah Lavell, 01952 290905, or email training@thelia.org.uk

For up-to-date information follow us on Twitter @sll100

Trotter Paterson Lecture, Bishopsgate Institute, London EC2

Bishopsgate Library. Tom Morris/Wikimedia Commons