How Human Centric Lighting increases productivity
Written by Tim Greenhalgh
Companies that focus on providing the best quality lighting in workplaces reap a great range of benefits, not least greater productivity.
Lighting with people in mind – Human Centric Lighting (HCL) – has been shown to have positive effects on health, wellbeing and performance of employees. Numerous studies support the view that well-designed HCL illumination has visual, biological and emotional benefits.
Bad lighting has been shown to have a significant effect on concentration and productivity as well as the overall feeling of health and wellbeing. And people are the most important part of any business, as well as the biggest cost.
A study by industry association Lighting Europe shows that HCL increases the vision, performance and well-being of people. With a 4.5% increase in productivity along with a reduction of 2% in errors and accidents in the workplace.
Lighting Europe’s strategy for HCL to encourage businesses to build workplace lighting design around three key points:
- Vision – Sight, safety and orientation
- Body – Alertness, cognitive performance and sleep/wake cycle
- Emotion – Mood, energise and relaxation
It’s important for lighting to provide visual comfort and which is suited to the task, while having access to applications that reduce downtime and improve employee productivity. For effective HCL, employees should have the facility to personalise illumination around their work area.
Studies show that giving people in open-plan offices local control of lighting can increase job satisfaction and lower stress. And in social spaces, like break-out areas, lighting that provides a livelier and more engaging atmosphere is very effective.
And where people are carrying out different activities, they need control over local lighting. So, for example, a control and instrumentation engineer working in process control room lit at 300 lux (a measure of illuminance) may need a desk with a lamp to study a wiring diagram.
It’s a surprising statistic that people spend 90% of their time indoors so the best quality light that is in tune with people’s natural rhythms is very important. Studies highlight a deep link between light and circadian rhythms, our “built-in clocks” that determine sleep cycle, stimulation, and relaxation.
When you consider that throughout a sunny day people outside are get 100,000 and on a cloudy day 10,000 lux, generally in offices people get a maximum 500 lux, often much less.
Studies also show that well-designed lighting decreases depression while improving mood, energy, alertness, and productivity.
One study showed that staff working with artificial light were more likely to feel tired towards the end of the working day than those who had natural light work areas, and who were able to work longer.
There is also a firm link between exposure to natural light during work hours and sleep, activity and quality of life.
People with windows in their workspace received 173% more white light exposure while at work and slept 46 minutes more each night on average. The study found that staff without windows had higher levels of “daytime dysfunction”.
Ideally, HCL strategies will be mindful of the need for maximum provision of natural light. However, in many workplace environments, the building design prevents this so it is important to use light sources that mimic natural light as accurately as possible.
Colour is crucial for effective HcL as it has a big effect on our emotions but it is also a complex balance between intensity, temperature and hue. Studies indicate that a higher colour temperature stimulates alertness and focus by suppressing melatonin, the sleep hormone sensitive to the blue range in the spectrum.
Range of illumination
Apart from the specific qualities of light, a well-designed workplace will provide the range of illumination that ensures people can work most effectively.
The Health and Safety Executive guidance is for companies to provide different levels of lighting that are required for varying types of work. It advises:
“Close, accurate work like soldering a control panel needs higher light levels than walking down a corridor. However, when considering lighting, a number of different factors need to be considered such as colour, contrast, glare and so on.”
So, for example, in reading a lengthy report, excessive brightness and large differences in contrast can cause fatigue and distraction. While higher light levels help, it’s important to design for low glare and a degree of uniformity.
And while a process control room should have illuminance of 300 lux, according to HSE guidelines, a corridor or walkway may only require 50 lux and studying an engineering drawing may require 750 lux.
Absenteeism costs UK businesses an estimated £36 billion each year – and poor lighting plays a part. Some artificial light sources that cause glare or flicker on screens have been linked to eyestrain, blurred vision, dry eyes and headaches.
Bad lighting also contributes to spinal complaints and other musculoskeletal injuries because employees sit awkwardly or shift their bodies into poor postures if, for example, they strain to read under poor lighting conditions.
HCL design that is most effective will also be in control of directional sources of light that can cause glare, one of the most tiring conditions for employees. Effective use of blinds, glare filters and up-lighting is important here.
Companies that adopt HCL as part of their overall human resources strategy should see measurable improvements in the productivity, health and wellbeing of their employees.