Mind-altering light

Office spaces don’t always lend themselves to spectacular lighting design, but after groundbreaking research into the effect light has on our mood, office lighting is taking a far more interesting turn. Lighting looks at one of the largest dynamic lighting projects in Britain

These are exciting times. The development of LED technology has put a renewed focus on the science behind lighting, and we’re demanding more from luminaires in terms of both quality and efficiency. It’s perhaps fitting, then, that global pharmaceutical company Astra Zeneca took this one step further with a dynamic lighting concept that works with the biology of the human body.

Scientific discovery
A quick online search reveals numerous studies into the impact of light on a person’s behaviour and performance. Without getting too bogged down in the science of it, until recently scientists thought there were only two types of photoreceptor in the eye - rod cells and cone cells - that convert light and colour into a visual representation of what’s around us (sight) . Then in 2002, a third type was discovered: the photosensitive ganglion cell. Crucially, a link between this third photoreceptor and the production of melatonin (a hormone affecting our sleep-wake cycles) was also established. Put simply, this means that the temperature and level of light around us has a direct physiological effect on our behaviour, making us drowsy or more alert depending on the time of day.

This had its uses for our more primitive ancestors whose activity patterns depended wholly on sunlight. But as you may have noticed, electricity now plays a fairly major role in our lives. Thanks to artificial light, we might start work a few hours after the sun rises and carry on long after it has set. This is where architectural lighting, if properly designed and managed, could potentially intervene to boost activity levels.

Ideas into practice
Robert Hale, a senior engineer at Astra Zeneca, came across this concept four years ago. “I’d been following research in the lighting press, and Philips had started publicising its blue lamp technology,” he says, referring to separate studies on cool blue light - replicating a summer sky - that triggers our bodies to be more active and energetic. “A dynamic lighting concept fitted in with Astra Zeneca’s corporate view of keeping staff content and highly motivated.”

Having clued up on the affects of different levels and temperatures of light, it was only a matter of months before the opportunity arose to put such a concept to the test. Astra Zeneca invested in a major capital project for a new research development in Macclesfield: a large laboratory with four floors, a large office, atrium, meeting rooms and leisure areas. “It’s a very diverse and multifunctional building,” adds Hale, highlighting a real need for flexible lighting.

Astra Zeneca worked in conjunction with Hoare Lea Lighting to prepare lighting designs, with detail design from Cross Services. Having carried out trials in a full scale mockup on the site, cool 8000K T5 fluorescent lamps were decided on for the laboratories with surface DALI dimmable luminaries to provide glare free lighting using micro-prismatic optics. “It’s a modern building with quite a dark feel in the body of the laboratories, so we called on blue lamp technology to replicate daylight. It was very successful,” says Hale.

Brightening the mood
Across the offices and meeting rooms, dynamic lighting played its part. “With a ceiling height of 4.5m, we had the unique opportunity to do something more interesting than usual in an office space,” Hale continues, going on to explain one of the largest dynamic lighting projects carried out in the UK. Suspended direct/indirect light supplied by Wila Lighting was used, with a 2.5m long dynamic luminaire suspended from DALI bus Eutrac. There are 12 lamps in total on DALI control: two 24W, 4000K lamps in a direct section at each end provide white reference light to the working plane; cool 17,000K indirect light is provided by two 24W lamps at each end.

On the work surface, this can be broken down into individual values:

• Indirect 17000K Maximum level 687 LUX
• Indirect 3000K Maximum level 358 LUX
• Direct 400K Maximum level 288 LUX

Philips lighting controls handled the dynamic lighting element, and a number of trials were set up with Philips beforehand to work out the necessary colour levels and temperatures across different environments. “We adapted it to the working hours of staff,” explains Hale. “The science was that blue light early in the morning would stimulate staff as they started work, so a high cool illuminance kicks off the day moving to a lower and warmer level by lunch time. Just after lunch there is a cool blast and slight increase in illuminance, which then gently subsides to around 3000K and 300 lux by home time.”

The different values are programmed into the control system with fade times between each step. According to the theory of cool light, the eye is more influenced by ambient light than the luminance from the work surface. So although the total direct component gets warmer as lux levels increase, any physiological effect from the indirect light shouldn’t be affected.

“We called on blue lamp technology to replicate daylight. it was very successful”

The investment both of time and money demands a significant pay-off if dynamic lighting is to become commonplace. But other than scientific research carried out on cells in the eye, there are few practical applications of dynamic lighting in the real world.

Astra Zeneca is in many ways breaking the mould by introducing the concept on such a large scale, and any findings in terms of productivity levels or staff wellbeing will be of great interest. Understandably, though, research into the effects on staff won’t take place until a full 12 months have passed.

“We don’t want the impact of moving to a brand new environment to confuse results,” explains Hale. “After a year, we’ll carry out surveys and other tests to try and establish the effects of the lighting alone.” But so far, feedback has been positive. Any potential issues, like the staff’s reaction to a very cold light first thing in the morning, haven’t been a problem. “Because of the indirect component, once you’ve been under the cool light for a few minutes you stop noticing it.”

Lee Gunner, executive lighting designer at Hoare Lee’s Leeds office, is an advocate of dynamic lighting and sees a real use for it in the future, “especially where there is a lack of natural daylight”. As for the type of place that would benefit most: “Patient wards or residential care homes - anywhere where altering people’s moods for the better would really make a difference.”

But as with any concept, popularity can sometimes cause its own problems. Gunner warns that dynamic lighting faces being “over complicated by manufacturers. It’s essentially a dimming system using lamps with different colour temperatures. If manufacturers start making specific systems for it, the cost could go sky high.”

Project details

Project: Astra Zeneca research and development laboratories, Macclesfield, Cheshire
Lighting designers: Hoare Lea Lighting, Leeds; Cross Services, St Helens
Principal suppliers: Wila, Philips, Zumtobel
Photos: Redshift Photography

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