Let daylight in

Jyrki Kesti, Technology Director, Ruukki
May 29, 2017

We all know that we get energy and happiness from the sun and daylight. However, most of us have to work inside and then the only connection to the outdoors is through windows.

Many research have shown that daylighting increases occupant productivity and comfort, and provides the mental and visual stimulation necessary to regulate human circadian rhythms. Some studies conducted in the USA also concluded that commercial real estate with no windows leases for about 20 percent less than spaces with windows. There are also studies where the presence of daylighting considerably increased the sales volume in a retail shop compared to a similar shop without daylighting.

The importance of daylighting has been understood for a long time in offices and large shopping centres, but there are still a lot of working spaces especially in the industry and retail sectors without a natural connection to outdoors.


Daylighting reduces need for artificial lighting


Ruukki supplied large polycarbonate "daylighting windows" to the HAMK Sheet metal centre as one component of the near zero-energy concept. The main purpose of the windows was to improve working conditions by giving a feeling on circadian rhythm. But based on the first experiences, it was noted that windows create pleasant and evenly distributed light into the space so that artificial lighting is hardly needed during the light seasons.


It’s possible to save more that 50 % in yearly lighting energy

We carried out lighting simulations in the spaces where large windows were installed, and the results surprised us a bit: It would be possible to save more than 50 % in yearly lighting energy if daylight sensors were installed and lighting levels were adjusted by available daylight. The target level for illumination in the study was 300 LUX. But the results were almost as good for a 500 LUX case.



Pleasant daylighting is possible to realise in all kinds of buildings

Based on these positive experiences we decided to commercialise daylight windows as a part of our sandwich panel system, so that pleasant daylighting is possible to realise in all kinds of buildings. Opal or clear polycarbonate sheets with excellent thermal properties prevent glaring and excessive heat gains and create pleasant interior lighting conditions.


See daylighting for yourself – visit our near zero-energy building


You’re welcome to explore daylight windows in practice in our Technology Centre situated in the nZEB building in Hämeenlinna, Finland. Please contact me for further information.

Read more about the near zero-energy hall at greatestzero.com

Jyrki Kesti
Technology Director, Ruukki

Contact Jyrki on Twitter: @JyrkiKesti
Email: firstname.lastname@ruukki.com

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