80 NEW LONDON QUARTERLY – ISSUE fIfTEEN

BRIEfINg NOTES – ThINk TANkS

LED Lighting — a waiting game? Co-hosted by FUTURE Designs

Rapid advances in LED lighting have meant that efficiencies are on the up and costs on the way down. But how close are we to the technology proving a reliable, cost-effective choice for the office environment – and for those who design them?

A roundtable debate held at One Canada Square and hosted by FUTURE Designs sought to find out. Putting the case for LEDs was Andrew Bissell, director for lighting at Cundall Light4. And making a case against was Peter Raynham, senior lecturer at the Bartlett School of Graduate Studies at UCL.

LEDs have been with us now for some 10 years or more, said Bissell, and with the maintenance savings – and avoiding the disruption from having to do that maintenance – fitting them is a worthwhile consideration. Beyond the sustainability and design aspects of choosing LEDs, cost is one of the chief parameters. The first time Bissell was asked to put LED downlighters into an office space around three years ago, the cost was around three times greater and the energy consumption the same, give or take one or two watts of power. Today, however, the difference between a good quality compact downlighter at around £80-£100 and an LED of comparable quality coming in at between £100-£120 is quite close. But the LEDs have a 10 watt per unit reduction in energy consumption. ‘So suddenly, it’s worth doing’, he said, with the tipping point approaching where we can start to replace phosphorescents with LEDs. The inauguration of the Zhaga Consortium as a way of standardising LED modules will allow more people to work to the same standards, and the energy savings can pay for the cost of the product. LEDs now last

for around 50,000 hours, with some claiming more, so with dimming and turning them off when not needed they could last for 20 years, with five-year warranties from manufacturers. So, said Bissell, if this is the pace of change of LEDs in terms of cost and maintenance in two years, where will we be in two more years’ time?

The design of LEDs will also deliver energy savings and better quality spaces as well, with light where it is needed, not blanket levels of light across the floorspace. ‘Once you move away from putting light everywhere to putting light where it is needed, you can save 30 per cent of energy.’ It is also a point source of light, so easy to control, can offer greater flexibility compared with other light sources, and can tolerate multiple switching. And finally, LED products can be tunable, with warm colours in the morning and night, tapping in to circadian rhythms and thereby offering more in terms of health claims. Finally, with regard to sustainability, LEDs are smaller and use fewer raw materials, with a knock-on cost to delivery.

But it is cost that is one of the chief bugbears for Peter Raynham, speaking against LEDs. ‘There is no doubt that making LEDs is currently a very expensive process and is likely to remain that way for a very long time’, he said. The extra cost is reflected in the nature of the LED product, because it is being driven by a higher current density than it would like to be. Reduce that current density and we could make a ‘really fantastic lighting product’, but nobody would ever buy it because it would have far too few lumens for the cost of the chip. ‘We could buy 50 lumens for £2 and we would get a really good product. At the moment we’re probably driving LEDs

around 10 times harder than they’d like to be, so we’re losing efficiency, we’re losing lifetime, we’re losing lumen maintenance. We’re losing overall system performance.’ And the LEDs sold have to be at 50,000 hours’ life in order to justify the payback. Pretty much the whole market is being sold at L70, so at the end of the LED life only 70 per cent of the lumens are being achieved compared with on day one of the product. ‘So we have to cheat. We know that if we install an LED luminaire today, five years down the track we’ll have a gloomier situation. That is a fundamental problem.’

Another issue is that of production consistency, says Raynham, with a spread of colours. But the chip manufacturers are grading them – ‘binning’ all on different standards, meaning you cannot buy the same characteristics from two chip manufacturers. This is a technology moving too quickly – standardisation is coming, but to participate in the Zhaga (a consortium for the standardisation of LED engines) process is expensive, making it a big players’ club. Product information as it percolates through the supply chain is patchy, and there are a lot of electronics companies selling LEDs ‘who don’t know what light is’, with the result being ‘rubbish products’ on the market. Specifying is also tricky. Usually specifying lighting products is done around 18 months to two years before a project goes on site. But the best available LED product today will not be so in two years’ time, causing significant problems for the design industry. LEDs are just another light source, said Raynham, albeit with good features and advantages – the real trick will be to avoid the retrofit path. But while the price is so high there are limitations to the exploitation of

NEW LONDON QUARTERLY – ISSUE fIfTEEN 81

BRIEfINg NOTES – ThINk TANkS

their benefits. The money you might spend on installing LEDs might be better spent on more efficient lighting controls for a linear fluorescent solution, he added.

Discussion of these two points of view was extensive and varied. Iain Trent, senior project engineer at Land Securities and of the BCO, which is compiling a guide on the whole LED lighting issue, said that for a typical 20,000 sqm office, you are talking about an uplift of around £200,000-£300,000 – a significant amount of money to try and put past a development manager. On efficiency, some LEDs are now on a par with the eco light, and savings on maintenance budgets are ‘pie in the sky’. What will drive LEDs will be arguments from agents and, at a high end of the market, fashion, where they will become an accepted additional cost.

At 5 Broadgate, said UBS’s Jason Clark, they will be around twice the cost of traditional fittings – his firm will be moving away from a chequerboard approach, bringing the number of fittings down to create savings. ‘But with an office this big your staff expect LEDs because that’s what they have been told. You shouldn’t underestimate the power of people.’

So is this what the market wants? This is the way technology is going, say the agents. That is according to Warwick Hunter, development manager at Great Portland Estates, who added that the TMT sector is occupying at a density of 1:8, where LEDs could offer more flexibility. In a design sense, said Martin Miesowicz, director at TP Bennett, LEDs offer new opportunities for architects, especially in exteriors, with almost unlimited possibilities to enhance the whole building. ‘Lighting becomes a design tool’, he said, with architects designing a building for a 24-hour appearance. A huge spectrum of colour is available. Furthermore, said Phil Hutchinson, joint managing director of BDG architecture + design, there is more variation on lighting in the work environment now, with the emphasis being on greater control on comfort and choice, with heartening approaches from developers like Derwent London.

Miesowicz said one of the tasks at hand is to educate on what is good light, with many people thinking more light is better light. Wrong. ‘It is about the right amount of task light for the individual user and the task in hand’,

he said. But another factor is that with more tablet computers and less paper work, the way people work is changing – there is less of a need for light ‘to read the fourth carbon copy any more’, said Raynham.

But perhaps it still comes back to cost, especially on retrofit, said host Paul Etherington, planning and development manager at BNY Mellon, even with that move towards task lights and even light sources built into furniture, suited to the jobs in hand. ‘I’m still not quite sure whether we’re ready to jump just yet.’

For Raynham, the real change that is being seen is in the end of architectural lighting designs. Look in the AJ and there are beautiful pictures of empty buildings, he said. ‘We’re starting to see that that isn’t an interesting thing to do any more. There’s no point in having a building unless you’re going to populate it with people, and it’s probably what the people like in the building that is far more important than anything to do with how nice the building looks. What we’re starting to think more about is lighting in volumes, and not lighting in surfaces.’

Or, as Andrew Bissell of Cundalls put it, ‘It’s about keeping it simple. And appropriate.’ NL