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Monday blues – and counting down to our panel debate at Light24

Monday blues?

Social jetlag – getting to bed and waking up more than an hour later than usual over the weekend will give you that groggy feeling on a Monday. Just three hours delay on Friday and Saturday can increase blood pressure – Acute social jetlag augments morning blood pressure surge: a randomized crossover trialand regular social lag (just one hour or more variation) can increase your risk of chronic kidney disease – Association between social jetlag and chronic kidney disease among the Korean working populationand increase your risk of feeling stressed at work – Association of sleep duration on workdays or free days and social jetlag with job stress.

As the mornings get darker and colder up here in the North, it’s even harder to rise and shine.

You can’t undo your weekend – but you can take control of your Monday morning by giving your body clock a blast of bright light first thing.

If your commute is all underground, it’s still dark when you arrive and you can’t sit near a window, artificial lighting can help.

One study found dynamic lighting that delivered higher melanopic lux in the morning (931± 484 melanopic lux in the test v   730 ± 390 melanopic lux in the control) brought the timing of melatonin onset (one of the markers of circadian entrainment) earlier that evening – Optimized office lighting advances melatonin phase and peripheral heat loss prior bedtimeThere are a number of studies including these that suggest that lighting that changes over the course of the day can improve visual comfort and engagement and even brain activity in day-active office workers – An experiment of double dynamic lighting in an office responding to sky and daylight: Perceived effects on comfort, atmosphere and work engagementThe effect of dynamic correlated colour temperature changes on alertness and performanceContrasting dynamic light scenarios in an operational office: Effects on visual experience, alertness, cognitive performance, and sleepDiurnal effects of dynamic lighting on alertness, cognition, and mood of mentally fatigued individuals in a daylight deprived environment, but the ‘perfect light recipe’ for circadian entrainment is still in debate.

If you’re still struggling to stay awake, a power nap might just help. This fascinating review of the nap paradox explains that just ten minutes is optimal to boost memory, focus and even help you manage your mood. Equally, chronic daily napping is associated with a range of poorer health outcomes including cognitive decline, hypertension, diabetes, with a potential link with inflammation – Exploring the nap paradox: are mid-day sleep bouts a friend or foe?

Morning light is only half the picture though.

You need to make sure you let your brain know it’s time to switch off. This study found half of homes had bright enough light to suppress melatonin by 50%, although there are wide range of individual responses (0–87% suppression for the average home), children are more sensitive than us older folk – Evening home lighting adversely impacts the circadian system and sleep.

Even when you’ve turned off the lights indoors, light pollution from the street can still stop you getting your beauty sleep, contributing to mental and physical health problems – Sleep problems mediate the association between outdoor nighttime light and symptoms of depression and anxiety: A cross-sectional, multi-city study in BulgariaAmerican adolescents living in areas with the highest light pollution were at 16% higher risk of anxiety disorder, even after adjusting for socio-economic and other factors – Daily rhythms, light exposure and social jetlag correlate with demographic characteristics and health in a nationally representative survey.

Making sure it’s dark with black-out curtains, switching off standby lights or using an eye mask will help us all to feel brighter tomorrow.

 

Simple pleasures 

Have you ever smiled at a child’s eagerness to press the button at the crosswalk lights?

It turns out we’re still kids at heart, even when it comes to lights at work.

Even if the ambient lighting delivers optimal conditions for productivity, we still believe we’re more productive and comfortable and even complain less about dry eye and computer vision syndrome when  we have a bit of control over the brightness and colour temperature at our desk.  Control over lighting can even boost thermal comfort too – Personal control of correlated color temperature of light: Effects on thermal comfort, visual comfort, and cognitive performance.

That uplift in satisfaction may be due to wide variations in personal preferences and needs – Preferred luminous conditions in open-plan offices: research and practice recommendations, with women tending to prefer lower light levels and warmer colour temperatures to male colleagues – Effects of illuminance and correlated color temperature on emotional responses and lighting adjustment behaviors. Personal control can even reduce energy use by up to 30% – The Energy Saving Potential of Occupancy-Based Lighting Control Strategies in Open-Plan Offices: The Influence of Occupancy Patterns.

As the cost of retrofitting  lighting controls falls and machine learning tools start to predict and support our preferences to optimise comfort and energy use, this simple upgrade may be worth adding to the shopping list, even for refurbishment projects. LightLearn: An adaptive and occupant centered controller for lighting based on reinforcement learningOffice light control moving toward automation and humanization: a literature review.

But how do you offer a degree of personal control in an open plan office?

This study notes that most of us will do our best to consider others when changing the lights. It also explains that it’s the choice that counts rather than the setting itself. So when the options are set within a median range,  we can all feel in control without the problem of extreme contrast.  

It also notes four critical features in a successful scheme

  1. Location of controls – place them close to the relevant desk – most of us just won’t get up to make the adjustment, losing the benefits of comfort and energy use too.

  2. Smallest-possible zones – the more people involved, the greater the risk of conflict

  3. ‘Slider’ rather than ‘scene’ interface to facilitate finding a middle ground
  4. Gradual rather than sudden shifts will minimise visual disturbance – your colleagues might not even notice. 

It concludes with the observation that we may not value controls if we haven’t had them before. But once we do, we’re very reluctant to give them up.

 

Counting down to our panel debate at Light24

We’ve been wondering why we, the people who live and work in ‘smart’ buildings, so rarely get to be in the driving seat when it comes to controlling the lights. It’s odd because just having access to the light switch comes top of the list when it comes to our belief that our workplace provides optimal conditions for productivity – The impacts of building characteristics, social psychological and cultural factors on indoor environment quality productivity belief.

Perhaps it’s because there are so many stakeholders with competing interests and the critical decisions are so often made years before the tenant gets the keys.

So, given that the end user is almost never around when the system is designed, who should stand up for the user experience when it comes to smart controls?

The architects and lighting designers with a vision for the space? The technology consultants and integrators who put the jigsaw puzzle together? The contractors and installers who wire it up? Or the facilities managers who have to keep the show on the road?

What do you think?

Get in touch!