The spectrum of lighting is the most important at school lighting

11 02 2012

In a few schools around the world, is currently some testing going on, a new kind of school lighting. Variable factors are lux amount and color temperature. It is said to bring major benefits for example  in reading speed. That would be excellent.

Color temperature options are from 2900 to 12000 K. The teacher can change the lighting in the classroom at will. A variety of lighting situations is considered to be too much for some teachers and they would like to make it easier. It is excellent that schools pay attention to lighting.

Unfortunately, the most important thing has been forgotten. The light spectrum is the most important thing for lighting-related work, including child development, learning. It would be interesting to see the experimental spectra of the light tubes used in classes. I suspect that the spectrum is incomplete, like this:

3-band light spectrum

3-band light spectrum

The spectrum should have been complete, continuous, like this.

Full spectrum

Full spectrum

It is known that one-sided light, for example, yellow light, is harmful to humans. In school lighting those four color temperatures, two of which are yellowish, 2900 and 4000K, are one-sided (not full spectrum) light. 12 000 K is already the second end of the color temperature: the light is blue. 6000 K is also somewhat blue. There are no long-term studies of how a child develops under one-sided (non-full spectrum) light. However, there are studies, where yellow light causes health problems.

Instead, under full-spectrum daylight lighting conditions, from which a true daylight is the best example, children’s physical and mental development is as complete as possible, when considering the effect of light.

Children need all the wavelengths of light, so that for example endocrine glands develop normally and growth in height goes such as each child’s growth hormone secretion allows.

I believe it´s irresponsible to make human experiments in which pupils are tested with 3-band light. At least the matter should be discussed with the children’s parents and teachers. These experiments can be compared with, if vitamins and minerals are removed from the school food. After all, they do not affect the flavor of food.

Special lighting, with four different color temperatures, costs around 4000 – 5000 euros per classroom. If a new class is equipped with high-quality lighting and full-spectrum lamps, the cost is around  2000 – 3000 euros. If there already is fluorescent lighting in the class, the cost for replacement light tubes, full spectrum daylight lamps,  is around 240 – 480 euros depending on the size of the class.

I would argue that full-spectrum daylight lamp lighting achieves better educational results than illuminating the children with different-colored lamps.

The light should have a positive influence on health. Basel University researcher Christian Cajochen says that artificial light can also have a very negative impact. Light should be approached as drugs. It should be of correct constitution and also be taken by right doses.

Who is responsible if school children´s development is disrupted due to the lack of the acceptable light spectrum?




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