Colour Temperature and Productivity

CGE-Colour Temperature and Productivity
Lighting quality can play a large role in workplace productivity. In an age where efficiency is held in high regard, no detail can be overlooked. This includes the quality of light in the workplace. Used correctly, different methods of lighting can create a more productive, happier, and healthier environment.

Lighting Variations


First off, let’s look at the different variations of light. The temperature of light is measured in Kelvin (K) for absolute temperature based against a black-body that sits in the visible spectrum between 400 and 700nm (Figure 1).

The Visible Spectrum

Figure 1 - The Visible Spectrum


This range includes light that can be categorized as warm, mid-range, or cool. Warm can be categorized as any colour temperature up to 3500K, Mid-range can be categorized as between 3500K and 5000K, and Cool light can be categorized as any colour temperature greater then 5000K. These colour temperatures can also be seen represented in the center of the chromaticity diagram in Figure 2.

Chromaticity Diagram

Figure 2 – Chromaticity Diagram


Warm Light – Up to 3500K


This range includes reds and yellows, where the light being emitted from a burning match or a fire are good examples. Most incandescent bulbs are also in this range.

1000-3500K

Figure 3 – 1000K-3500K Range


Mid-range – 3500-5000K


This colour temperature includes lighter yellows to the colour of sunrise. Compact Fluorescent Lamps can also usually be found in this range.

3500-5000K

Figure 4 – 3500K-5000K Range


Cool Light – Greater than 5000K


This range includes bluish-white and blue colours. Daylight and the sky on a clear day are both examples of this colour range.

5000-10000K

Figure 5 – 5000K-10000K Range


How do these colour temperatures translate into better productivity?


First, we have to look at how different light temperatures affect the human body and then we can translate them into professional settings. Research has found that a higher quality, cooler light has a positive effect on the human body in many ways. First off is the suppression of melatonin levels that make us feel tired or fatigued. This leads to greater alertness and ability to concentrate. Cool light is also easier on the human eye. Participants of a study done by Antoin Viola, et al reported lower levels of eye strain, less eye discomfort, and less eye fatigue. Participants also reported better sleep quality and duration leading to feeling less drowsy during the day. This can be attributed to an increase in nocturnal melatonin after bright light exposure throughout the daytime. Additionally, participants subjected to cooler colour temperature lighting found that they had a positive increase in mood throughout the day.
Using this information, we can begin to look at how workplaces are currently illuminated, and start to optimize them in different ways.

Warm Lighting


Just because cool lighting with higher colour temperatures can make individuals more productive, it does not mean that warm lighting is useless. In fact, it is actually still very useful in the right environment. Warm lighting can best be used in intimate or casual settings such as break rooms where trust and comradery can be promoted, leading to better cohesion across functional teams, as well as a more welcoming atmosphere in the workplace.

Mid-Range Lighting


Mid-range colour temperatures should also not be discounted. Since they are a blend of warm and cool colours they can be used to both build a trusting atmosphere as well as promote productivity. That said, this colour temperature would be effectively used in board rooms and meeting rooms where individuals need to generate and share ideas while working together.

Cool Lighting


As mentioned above, cool lighting can be used to promote wakefulness and attentiveness in individuals that are exposed throughout the day. Brainstorming areas would benefit from cooler lighting since individuals are more able to concentrate on deliverables and be as productive as possible. General workspace lighting would also benefit from cooler lighting since individuals would be more alert and less lethargic throughout the day. Cooler lighting in general workspaces would also aid with increasing workplace morale since research has shown that individuals get a higher quality sleep after daytime exposure.



References
Viola, A. U., Et al. (2008). Blue-enriched white light in the workplace improves self-reported alertness, performance and sleep quality. Scand J Work Environ Health, 297-306.