How is lighting ergonomic?
Next time you’re reading something printed, notice the position you are standing or sitting in as you read it. Do you move to get better lighting? Do you position your body in a way to help improve the visual contrast of the text, reduce glare or avoid a shadow? That very movement is the essence of ergonomics.
How can lighting reduce operating costs?
According to the US Department of Energy, 51% of the energy used in commercial buildings is consumed by lighting systems. However, many existing systems have much higher than recommended illumination levels from overhead lighting. In instances where too much illumination is provided through overhead lighting, companies can reduce their power usage and associated costs by simply reducing overhead light levels and applying proper lighting for specific tasks.
How does proper lighting increase performance?
According to The American Optometric Association, excessive overhead or ambient lighting levels reduce the apparent visual contrast on computer screens due to glare.
“Contrast (which is reduced by glare) plays an important element in visibility. Low contrast objects are difficult to see, regardless of their size. Increasing task contrast is an important means of increasing overall performance.”
The Bottom Line
Optimal task illumination levels through the use of task lighting will help improve user ergonomics, reduce operating cost and increase worker performance.
Achieving proper light levels
Light levels are most commonly expressed “Foot Candles” (fc). The Illuminating Engineering Society (IES) Lighting Handbook provides detailed light level recommendations for thousands of specific applications. General rules of thumb are:
- Visual Tasks of medium contrast or small size require 50–100 fc*Visual Tasks of low contrast or very small size require 100–200 fc*Users over the age of 65 should be provided with 2 times the lux or foot candle light levels.
* * IES Lighting Handbook 10th Edition
What to look for in the light produced from a task light
Supports IES foot candle recommendation for the task: Understanding the user and the task at hand will dictate how much light is required. Photometric maps illustrate the footcandle power over a specific distance and area.
High lumens per watt: The higher the lm/W the more efficient the light.
White light color: “White” light is typically perceived between 3200–4100 K. Light less than 3200 K begins to appear orange or red, while light above 4100 K begins to appear blue.
Color Rendering Index (CRI) above 80: CRI determines how “true” colors appear. CRI below 80 will begin to make objects appear noticeable different from natural sunlight.