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How to fill a windowless room with sunlight

The COELUX project is using LEDs to simulate natural light. ©Shutterstock/rangizzz
The COELUX project is using LEDs to simulate natural light. ©Shutterstock/rangizzz

High-tech LED technology and sophisticated optical systems are being used to recreate natural sunlight.

Imagine sitting in a windowless room yet having the feeling of the sun shining on your face. This unique experience is now possible thanks to the COELUX EU-funded project which recreates the physical and optical effects of natural light indoors by simulating the diffusion and transmission of sunlight through the atmosphere.

The high-tech window system designed by the project, which was on show at the EU’s Innovation Convention 2014, uses energy-saving LEDs (light-emitting diodes) which reproduce the same spectrum of light as sunlight. It also includes a sophisticated optical system to create a sensation of distance between the simulated sky and the ‘sun’.

‘You can experience sunny skies anytime, anywhere.’

Professor Paolo Di Trapani, coordinator of COELUX

The system uses nanostructured materials only a few millimetres thick to recreate the way radiation is scattered as it passes through the earth’s atmosphere.

‘With COELUX, you can experience sunny skies anytime, anywhere,’ said Professor Paolo Di Trapani, coordinator of the project and a physicist at the University of Insubria in Como, Italy, whose research has been driven by the desire to recreate natural light for the past 10 years.

The system provides three settings so that users can experience the light of Northern Europe, of the Mediterranean and of the Tropics.

The researchers received funding as part of the EU’s research for small- and medium-sized enterprises (SMEs) programme, and they have used it to invest in research and development, and to fund the cost of demonstrating the product.

‘We strongly encourage other SMEs to apply for EU funding as it opens windows of opportunity,’ Prof. Di Trapani said.

International year of light

The United Nations has proclaimed 2015 as the International Year of Light to raise global awareness of how light can have a positive influence on our health and wellbeing.

Warm, artificial, direct sunlight illuminates and enhances objects, making domestic and public spaces more attractive and welcoming. The play of light and shadow gives them volume and shape and alters the way people react and interact with their surroundings. 

The COELUX project recreates the physical and optical effects of natural light indoors.The COELUX project recreates the physical and optical effects of natural light indoors.The COELUX light diffusing technology will benefit anyone who does not get enough sunshine. It has been designed with a focus on the healthcare industry, but can be applied in retail, hospitality, museum, airport, underground transport, spa, sports centre, cinema, office and industrial environments.

Those working or living in underground spaces, either due to space restrictions or as a way of coping with extreme climates, such as in Canada or the United Arab Emirates, are set to benefit greatly from the technology. The same is true of residents of countries located furthest from the equator, close to the Arctic or Antarctic, who often experience very little natural light for long periods of the year. 

The COELUX technology will be ready for market towards the end of 2014, and is poised to take a share of the global lighting market, which the EU says is estimated at EUR 58 billion. That means it is a significant business opportunity for the project partners and network of European enterprises which will be involved in its production, demonstration and implementation.

Michael Jennings, spokesperson for European Research, Innovation and Science Commissioner Máire Geoghegan-Quinn, said: ‘Many areas of our lives – from energy, transportation, medicine, food safety, health and well-being – are being enhanced and even revolutionised by nanotechnology. COELUX is a great example of how science can turn a simple idea that is difficult to achieve – replicating sunlight – into a reality. It clearly has huge potential to make a difference in people’s lives.’

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