Singapore 24th May 2011
As lighting designers we are only at the beginning of really understanding the “physics” of LED lighting and its effects when applied in space, at least I do. With the technology continuously changing, improving, it is hard to build up some experience as today’s knowledge is yesterday’s history tomorrow! Every project has different needs and I am still building up my experience “porte-folio” using LED lighting technology in different applications.
Today I spent a good part of the day in experimenting in dimming LED. Being used to the fairly linear dimming characteristics of incandescent, LED MR16 retrofit lamps have quite different characteristics, at least the latest Philips type I am using. Dimming this LED from 100% to 50% hardly makes a dent, only when reaching about 30% is there a noticeable change in lighting intensity. The lowest level I could reach was about 10% before it sort of cut off. Overall not bad but it’s just the different characteristics I need to get used to. I also tested LED candle lamp replacements which again have different response curves, this time the real impact only happened in the last 10%, but allowing me to dim down to 1% (!).
The main thing is that we still have very little experience with LED when it comes to the long term effects as we only have the technology at our actual disposal since very recently. Even with a proclaimed 50,000 hours life span it would take more than 10 years at 12 hours usage a day to find out what happens over its life. It is not surprising that still many companies, developers and government authorities are still testing the impact of LED lighting before committing themselves to massive LED replacements.
In Light Watch today a test road currently in use in Singapore were for the next 3 years the Land Transport Authority (LTA) is testing LED road lights to better understand the long term benefits. Issues like performance, energy saving, durability and maintenance challenges are part of the trial study. Key of course is to compare apples with apples, in other words achieving the same lighting standards in terms of light quality, lighting levels, uniformity and glare control. At the heart of it all will certainly be a value for money assessment and the actual savings that can be achieved. A story to be continued, for sure…..