ELECTRIC LIGHTING – DESIGN TECHNIQUES

ELECTRIC LIGHTING – DESIGN TECHNIQUES

What is the purpose of electric lighting?

• To extend the useful hours in the day

• To support the performance of a visual task

• To display or reveal something

• To control how something appears

• To attract interest

“Lighting” is good elucidation when it provides sufficient luminance to enable the task to be performed efficiently, is superficial as comfortable, and people have a high level of satisfaction. Good lighting design is not simply about achieving a required luminance on the working plane; it is about creating and controlling the lit environment.

Light Sources

Color Rendering – This is the accuracy with which a light source reveals colors. The common method of measuring the color rendering is the Color Rendering Index (CRI). The method has some limitations, but is a reasonable sign of the performance of various light sources.

Energy efficient lighting is not simply the minimizing of energy input through higher utensils efficiency, or reducing luminance levels to the minimum that is tolerable. There is no advantage in a lower color rendering for general illumination. Ideally all installations would have color rendering induces of 100. The only limits are those of efficacy, life and cost that may accompany a high color rendering source. On that basis, with present lighting technology, I consider there is little justification for lighting any interior with a color rendering index of less than 80.

Work Stations

The solution to modern office tasks had tended to be workstations. These are individual or group enclosures with screens that shield the view of the remainder of the office. This works well to remove the distracting background, but also removes the distant view for relaxation of the eyes.

 Some simple guidelines for workstations are:

• The panels behind the VDU should have a reflectance > 50%

• The panel behind the VDU should not be a strong color

• There should be no shelves or hampers above the panel behind the VDU

• One or more panels should be low enough that the occupant can look over the top to a distant object or view

• The lighting in the space should have a reasonable horizontal component.