Abstract
In a laboratory study the impact of the surrounding light on alertness was study. Two types of
light sources were examined, LEDs and T5 fluorescent tubes. The illuminance level in the
working area was kept constant (500 lx), while the surrounding light was varied between 100
och 350 cd/m2
. Subjective ratings of the emotional status and the experience of the lighting
environment as well as physiological measurements of cortisol and melatonin levels in the
saliva were conducted. The results show that the higher the surrounding light the higher the
phsysiological cortisol levels. There were no significant differences in the experience of the
light, except that the LED light source were a little bit more bright. It should, however, be
stressed that the light sources were very well shielded and no glare were at hand.The results
should be interpreted with caution, but with the chosen LED light sources no harmful effects
were seen in comparison to fluorescent tubes. LED may be seen as a good alternative as long
as the lighting design is done careful so that glare is avoided. The study comprised 42 subjects
between 18-68 years of age, mean age 43 years. Preliminary results have been presented at
Energitinget 2010 and at CEEBELs conference in Katrineholm. During the spring a series of
presentations will be held.
light sources were examined, LEDs and T5 fluorescent tubes. The illuminance level in the
working area was kept constant (500 lx), while the surrounding light was varied between 100
och 350 cd/m2
. Subjective ratings of the emotional status and the experience of the lighting
environment as well as physiological measurements of cortisol and melatonin levels in the
saliva were conducted. The results show that the higher the surrounding light the higher the
phsysiological cortisol levels. There were no significant differences in the experience of the
light, except that the LED light source were a little bit more bright. It should, however, be
stressed that the light sources were very well shielded and no glare were at hand.The results
should be interpreted with caution, but with the chosen LED light sources no harmful effects
were seen in comparison to fluorescent tubes. LED may be seen as a good alternative as long
as the lighting design is done careful so that glare is avoided. The study comprised 42 subjects
between 18-68 years of age, mean age 43 years. Preliminary results have been presented at
Energitinget 2010 and at CEEBELs conference in Katrineholm. During the spring a series of
presentations will be held.
| Original language | Swedish |
|---|---|
| Publisher | Ceebel |
| Commissioning body | Swedish Energy Agency |
| Publication status | Published - 2011 |
Bibliographical note
The information about affiliations in this record was updated in December 2015.The record was previously connected to the following departments: Environmental Psychology (011036009), Gastroenterology (013240600)
Subject classification (UKÄ)
- Building Technologies