LED bulbs are very much on the agenda for the National Trust at the moment due to the significant energy saving they can provide, and with the larger properties containing many hundreds of bulbs the savings soon add up.
With this in mind I was interested to read an article in the New Scientist recently about how differing light colours can affect our mood and energy levels, and that there is still some way to go to produce the ideal LED bulb. The colour level of a standard bulb of any kind is fixed throughout the day, whereas natural light changes between dawn and dusk, and this is used by animals to regulate sleeping patterns. This means that in the evening, when natural light levels are preparing us for sleep, artificial light sources are telling us that it is still midday and overriding this natural effect. For the same reason it is advised not turn off TVs and computers before bedtime to allow the body to get ready for rest.
Comparison of light levels from various sources
Here is the link to the article (needs subsrciption)
If you can’t view the link above, here is a similar article from GE:
http://www.ecomagination.com/the-everything-bulb-can-an-led-change-like-the-sun
What a fascinating idea. I had never thought about the color/wavelength affecting my energy level, just the brightness. Thanks for a great post.
Thanks Catherine, yes it will be interesting to see how soon an affordable bulb can be produced that can solve the problems with fixed-colour lighting.
Good idea, I actually fall asleep to the tv all the time. Never thought about the color of the lights having an effect.
Have just realised that where it says light colour in the blog, it should read colour temperature – i.e. the colour of a black body radiator at a given temperature in kelvin, eg 2700K. Not just whether a light is tinted green or blue, etc.
Interesting that you fall asleep watching tv as the evidence says that light from tvs mimics daylight so should tell your body to stay awake. I guess if you’re tired enough you will sleep anyway.