A LoLo student enters the world of Daylight
The bulk of research during the first months of a doctorate involves reading journal papers, building regulation documents and software or equipment manuals – a rather solitary endeavour. The events organised by societies and organisations in a given field however, offer a chance to keep up with the ongoing dialogue between industry and academia, and their stance regarding policy decisions. In the area of Daylight there are two such organisations under the Chartered Institution of Building Services Engineers (CIBSE), the Society of Light and Lighting (SLL) and the Daylight Group.
On Tuesday February 18, 2014, the first one hosted the Trotter-Paterson Lecture in the Bishopsgate Institute building, one of the first buildings in London designed for electric lighting. This biennial event aims to bring together views on lighting not only from various academic disciplines but also industries. Prof Colin Blakemore (Neuroscience and Philosophy, School of Advanced Study at University of London, and Professor Emeritus, Neuroscience at University of Oxford) delivered this year’s lecture aptly entitled ‘Vision Impossible’. The speaker presented recent findings in vision-related research which suggest a general inability to detect changes in moving stimuli, as well as a peripheral vision of poor quality, with the exception of a small high-resolution focal area of vision (roughly equivalent to 2 thumbs at arm’s length distance), which inadvertently shifts as much as 3 times/second.
Videos and animations, chosen by Professor Blakemore as exercises to demonstrate these conclusions, were essential for the audience to recognise the shortcomings of our visual capabilities and perhaps re-think our reliance on vision for analysing our environment. On this topic the presenter went on to explain the process of translating visual to non-visual information as one based on the ability of people to retain only small snapshots of what we focus our attention to, then cognitively analyse and place these in sequence, based on past information (our understanding of the world) in order to create a mere hypothesis based on semantic descriptions. Thus, according to the presenter, is where the disparity between what we actually see and what we perceive (or think we know) lies. Lastly, Professor Blakemore touched on his recent involvement in the 2014 BAFTA nominated movie, ‘Tim’s Vermeer’, a documentary about optical devices made up of mirrors and lenses that were probably used by the 17th century Dutch painter Johannes Vermeer to create his photorealistic masterpieces.
The following day the Daylight Group met to discuss ‘Daylight in Schools’. The first part of the seminar revolved around the Priority Schools Building Programme (PSBP) which the government has in place to address the needs of schools that require urgent attention. Prof John Mardaljevic (Loughborough University) pointed out the limitations posed by using the long standing Daylight Factor as a compliance metric and described an alternative set of metrics that take into account both the quality and quantity of Daylight, and are based on the concept of Climate Based Daylight Modelling (CBDM). Daylight compliance requirements were for the first time specified by such metrics in the guidelines produced in 2013 by the Education Funding Agency (EFA), the government body responsible for providing design guidance for and approval of school buildings. EFA was represented by Richard Daniels who discussed the Daylight design criteria taken into account in producing the 2014 compliance documents which continue to use CBDM metrics.
David Mooney, of Atkins Global, presented amongst others a suggested PSBP Design Workflow for companies interested in bidding for the refurbishment and construction of UK schools. The second part of the day was devoted to a technical seminar. Professor Mardaljevic explained the use of CBDM in the new PSBP specifications while Imma Boada of Lledo Group showcased how education buildings can benefit from high performance prismatic skylights that provide maximum light transmittance, and 100% light diffusion, without glare discomfort and UV damage.
Lastly, on March 18, the Daylight Group hosted a joint event with the CIBSE Intelligent Buildings Group titled ‘Daylighting in Buildings: Energy, Health and Wellbeing’. The morning session was moderated by Prof Derek Clements-Croome (University of Reading) and started with Prof Debra Skene, (University of Surrey) presenting findings of numerous lab controlled experiments on the non-visual effects of light. It was concluded that people’s circadian rhythm is most responsive to blue short-wave light and that the timing of exposure to bright natural or artificial light (even from screens) significantly affected changes in the circadian clock. Dr Richard Hobday brought attention to the fact that infections spread mostly within buildings and to the need for further research on the benefits of the non-visible wavelengths of Daylight (UVB, UVA and infrared) before excluding them from buildings. Dr Sirinath Jamieson, of Biosustainable Design, stressed the importance of the building occupants’ perception of light and the feelings that Daylight can induce.
Prof John Mardaljevic (Loughborough University) presented a history of how Daylight performance is specified by leading compliance bodies and discussed the concept of CBDM. After a lunch break aptly timed to coincide with a free piano recital on the grounds of the Bishopsgate Institute, Professor Mardaljevic continued with current and potential applications of CBDM concluding that it doesn’t intend to replace the expert Daylight Designer. Instead CBDM is a reliable, repeatable and robust simulation method that provides insight into the rationale of the Daylight expert’s designs, making it easier to communicate and teach Daylight Design for optimum visual comfort and energy efficiency. The theme of energy harnessing through the use of Daylight was continued by John Aston, of Aston Lighting & Control, who discussed the role of Daylight linked light controls and gradual dimming in effectively lowering lighting energy consumption. This was further demonstrated by case studies presented by Zumtobel Lighting representatives.
The Q&A portion of each of the seminars sparked intense discussions between stakeholders. Witnessing the lively exchange of differing views, resulting from a range of actual experiences from industry, was invaluable. All in all, it strengthened the view that Daylighting is an exciting field where the first steps toward fundamental change have been taken and momentum is building up for a ripple effect to unfold.
Article by LoLo 1st year PhD student Nafsika Drosou
