Human-centric lighting represents a new way of using light in our lives, but it is understandable that there is some skepticism over its use and its effectiveness. But do we know enough about the technology to be using it in schools?
The picture is certainly a muddy one and something that we, at LuxLive, would like to try and resolve. The talk 'Are we experimenting on school children?' will take place at 13:30 on the first day of LuxLive in the Lux Arena. The panel will include Katharina Wulff of Oxford University and Dan Lister of Arup.
Following a conference in the UK earlier in the year, the International Commission on Illumination (CIE) issued a short statement entitled 'Non-visual effects of light – recommending proper light at the proper time', noting that our knowledge of the subject is still in the early stages.
The CIE went on to say that there is general agreement that the non-visual effects of light exposure depend on the spectrum, intensity, duration, timing and temporal pattern of the light. However, they also went onto say that a lack of understanding of the link between the light stimulus and the resulting non-visual response ‘seems to make tailored light application for a desired lighting effect impossible’.
In other words, if someone’s selling you a lighting product that they claim will have a particular non-visual effect, take it with a pinch of salt.
Nevertheless, more and more human-centric lighting installations are being installed in schools, such as this one in Malmo, Sweden, which was aimed at improving pupil performance. The human centric system replaced a fluorescent lighting scheme, a change which pupils claim has improved their concentration, making them feel more alert throughout the school day.
Earlier in the year we asked Lux's applications editor John Bullock (a HCL cheerleader) and our technology editor Alan Tulla (a sympathetic skeptic) their views on human centric lighting in schools.
'Teachers have long complained that it is difficult to maintain students’ attention throughout the day and it has been proven that students suffer from attention-deficit first thing in the morning and post-lunch,' John Bullock told Lux.
'A carefully-tuned system is overcoming these problems by introducing light into the classroom with a higher blue content in the part of the spectrum that subdues sleepiness. The same system is used at other times of the day when young children may be over-active. At such times, the lighting can be adjusted to reduce the amount of blue light entering the classroom in order to settle the mood of the classroom.'
But given that the general mood of any classroom will vary and the individual behaviour of students will differ, surely finding a human centric system that suits everyone will be a fool's errand?
'There has been a lot of experimentation in schools but the results have been quite different,' Alan Tulla added. 'For example, when children first arrived in the morning, one school used high levels of illuminance and high CCT to boost the student's concentration ready for lessons. Conversely, another school did the exact opposite because the children were excited when they first arrived and needed to be calmed down for their first lesson.
A manufacturer who promotes human centric lighting told me that these examples prove that it works. The school just has to decide what effect they want and the lighting can be adjusted accordingly. The question is, of course, what is a school actually meant to do? Somebody, somewhere, has to set the controls either to dim down or to increase the illumination and CCT.'
- 'Are we experimenting on school children?' will take place at 13:30 on the first day of LuxLive in the Lux Arena. The session will feature video from the Lindeborg school in Malmo, Sweden, mentioned above and a panel discussion will follow where experts take sides in the debate. Panelists include Katharina Wulff of Oxford University and Dan Lister of Arup.