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Beyond the lightbulb – controls and personal preferences in the workplace

This week I’ve been thinking about the business case for lighting in the workplace – how the light source is just a small part of the picture along with controls and personal preference and how the lighting choices we make today will be around for the next 15-20 years with two pieces about lifecycle costing. Rounding up with a couple of weekend articles – one about driving through tunnels and the other about midnight snacks…

You feel wonderful when when you’re in the driving seat… This fascinating paper explains just how important it is to feel in control of your working environment in order to feel you will be productive there. Light switches and controls seem to have the biggest impact – and control seems to matter more to men than to women… Hmmm. – The impacts of building characteristics, social psychological and cultural factors on indoor environment quality productivity belief

Cut lighting bill by 17.8% without upfront costs or capital investments? Just let your team decide whether to switch the lights on. Around half will prefer daylight. As daylight and outside views improve mood and productivity – and even help them to sleep better at night – Impact of Windows and Daylight Exposure on Overall Health and Sleep Quality of Office Workers: A Case-Control Pilot Study

Are you getting enough…? There is ongoing debate about exactly what ‘enough’ is. This study integrates light exposure at home and at work and found that the average average office worker receives 1,000 lux for just 72 minutes per day. Given that our bodies and brains evolved to respond to bright days (it’s around 1,000 lux outside even on a cloudy day), this may not be enough to keep you awake – or let you get a good nights’ sleep either… Personal lighting conditions of office workers: An exploratory field study.

This seminal work by Stewart Brand seems as relevant now as when it was written back in 1995, setting the foundations for whole life costings that go beyond upfront capital investment to look at how the different elements of a building need to perform over time, assuming a 30 year lifespan – from the 1-5 year lifetime of the ‘stuff’ inside to the 10 -15 year lifetime for the services. It puts a more expensive lightbulb and wireless controls in perspective. How Buildings Learn: What Happens After They’re Built

This excellent paper talks us through a detailed methodology for lifecycle cost analysis for retrofitting lighting with controls with two worked examples. It goes beyond energy efficiency to integrate occupant satisfaction, the impact of rising energy costs and over different time scales. Below 1.45 years, the numbers don’t stack up – but over ten, the case is compelling. – Combination of lighting retrofit and life cycle cost analysis for energy efficiency improvement in buildings

Have you ever noticed that your eyes take a moment to adjust entering a tunnel? It’s a critical moment for accidents – and accidents in tunnels tend to be more serious. Perhaps improving the colour rendering of the lights could help? This fascinating piece of research found that the optimal combination of colour temperature (2800k) and colour rendering (CRI85) can significantly reduce reaction times, reducing braking time which in turn reduces the likelihood of accidents and improve fuel efficiency too. – The Impact of LED Colour Rendering on Reaction Time of Human Eyes in Tunnel Interior Zone

What time you eat affects how your body handles the calories – a particular problem for shift workers – and party-goers stopping for a curry on their way home from a night out. When participants ate at night, tricyliceride levels (a lipid marker) were ‘similar to eating during the day, however, these levels at night were reached with consuming approximately half the calories’. – Time-of-day and Meal Size Effects on Clinical Lipid Markers

And two things coming up that you might enjoy. 

The first is a panel debate about glass to celebrate the international year of glass as part of the Exhibition Road Festival – link is here

And the second is another project I’ve been working on about quasiperiodic symmetry – we will be building the very first quasiperiodic tiling pattern that uses just a single tile – an incredible breakthrough from a team in Australia – as part of the Open University celebration of the brilliant Uwe Grimm. Link is here

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