Smart light for smart work
The lighting design in the spaces was designed in an automated circuit, adapted after the two working shifts (morning and evening). During the two eight-week periods, the participants could not manually change the light settings, except putting on the presentation mode when needed. In the summer period it is never totally dark during the day, only twilight, and in the winter period, there are only a couple of hours of light during mid-day.
During the winter, the mine workers did not experience daylight at all during the day, since it was dark both when they went down and came up from the mine. And in the summer, the situation was the opposite – they saw daylight both when they went down and came up.
– What we found out, while testing in two different periods of the year, was that they really felt the circadian lighting in a different way, Henrika Pihlajaniemi explains. When they came down in the winter mornings, they experienced the office space with normal standard office lighting as too lit. But in the summer evaluation they did not experience it like that, because they had felt the sunlight before going down. So, even though we are designing lighting for underground location you need to take into account the yearly rhythm of daylight as well. Especially during the winter time, they preferred the dynamic scenario where the lighting was dimmer and warmer in the morning, and then slowly increased. In my opinion, you should not break the balance between darkness and light. I believe, that it is the most beneficial for us humans to feel the whole circle, to be in balance with the extremes.