Light and humans

The influence of light distribution on the acceptance of office workstations

Everybody knows the effect of sunlight on the human wellbeing. We feel more active, more optimistic and healthier than on a rainy day in November. This natural effect can be transferred to the artificial lighting in offices.

The practical experience of lighting design therefore often shows that standardized and visual optimized lighting sets do not automatically lead to the desired and expected satisfaction with the lighting conditions at the workplace.  

That is why the DIAL GmbH surveyed the following issues within an experiment: 

1. Does the type of lighting influence the performance of office work?
2. How is the difference between direct and background lighting and between ambient light and accentuated light evaluated?
3. Is there a difference in the desired type of lighting at conventional office work and working in front of a computer?
4. How do different types of lighting influence the evaluation of room quality and the individual wellbeing?
5. How important is the lighting of space limitations, particularly with regard to wall areas?
6. Are lighting accents or highlights desired or are they perceived as disturbing and how do they influence the wellbeing?

Furthermore it was evaluated which influence the lighting design of a room has on the wellbeing of the office workers.

Results of study (abstract)

For lighting design the following principles can be extrapolated:

1. Brightness impression
   Regarding the impression of brightness of a room not only the horizontal illumination is crucial but also the lighting on vertical wall areas, in bigger rooms also on ceiling areas.
   
   Rules:
   > For a bright room atmosphere do equally illuminate the wall and ceiling areas.
   > Compensate the difference to the needed horizontal illumination of the workplace with an additional direct lighting element.
   
   
2. Accentuation
   Equal lighting of a room allows for an efficient vision but is often met with emotional refusal.  
   Uniformity means monotony and the lack of creative hierarchy. Brightness contrasts through accentuated lighting do enhance the acceptance of workstations.
   
   Rules:
   > Devide rooms in areas with high and low illuminance.
   > Set highlights in the field of vision.
   > Relate accented light to the room architecture and its furniture. 
   
   
3. Eliminate interference
   Every form of glare must be avoided. Looking directly into light sources within the face area is a potential interference factor for the wellbeing as well as reflections on screens and working materials.
   
   Rules:
   > Avoid direct lighting as the only lighting element.
   > Illuminate room areas.
   > Only use light sources with a good protection and light density control.
   > Arrange light sources to avoid reflections on screens and other working materials.
   
   
4. Regulation
   Optimized visibility and wellbeing are accomplished with adaptive lighting. Lighting conditions must adapt (or must be adaptable) to different lighting requirements and usage.
   
   Rules:
   > The desired lighting for a special task must be easily adaptable by a switch or a control unit.
   > Minimize the lighting variations to necessary means.
   > Enable the user to adjust the lighting conditions to his/her personal needs.
   > Automatically adjust the lighting conditions to different daytimes. 

The documentation of the survey can be ordered from the DIAL GmbH under www.dial.de.