LEDs and Lighting Buildings

15-04-2011

IÃ¯Â¿Â½ve been asked if LEDs have made any difference to the illumination of buildings (that's on the outside - not on the inside!)

So hereÃ¯Â¿Â½s a brief rundown of how we got to where we are Ã¯Â¿Â½..

The History of Lighting Buildings Ã¯Â¿Â½ an important bit of background:
Up to about 30 years ago, the only building illumination that you were likely to see would be from huge dustbins of fittings behind wire cages on cathedral greens. What changed was a fantastic breakthrough in lamp technology Ã¯Â¿Â½ the miniaturisation of the high-pressure discharge lamp (thatÃ¯Â¿Â½s the metal halide lamp, or HQI, to you and me). By shrinking the electrical lamp size from an unwieldy 250W to a delicate 70W it meant that lighting fixtures could also be made much smaller. (Here's a thought: take a look at Willy Meyer+Sohn's website to get some idea of how lamp technnology has driven the development of lightinf fixtures shape and performance)
(Now, there was a parallel development in the use of tungsten halogen lamps, but the relatively poor lamp life was always a problem Ã¯Â¿Â½ it was the metal halide (HQI) wot did it.

And as soon as we had these new lamps to play with, designers started playing around with the idea of fixing lighting directly to the building fabric, and the close-off-set principle was established. I remember it well.
(An aside: if you dare go out after dark and look at how most commercial buildings have been lit, youÃ¯Â¿Â½ll see that the fixtures have been positioned in locations where they CAN go, rather than where they SHOULD go. This is pragmatic design at its worst. And see below)

And for a few years, that was the only New Thing. Manufacturers started to play around with reflector shapes so light was used more effectively, but it was basically the simple act of bolting floodlight/spotlights onto building facades to push light around in fairly interesting ways. But the lamps were still the wrong shape to be really creative, being tubular, with a contact at each end (search for Ã¯Â¿Â½hqi-ts 70wÃ¯Â¿Â½ and see the image under Ã¯Â¿Â½shopping results and youÃ¯Â¿Â½ll see what I mean). So the lamp guys did it again and produced a single-ended lamp that clever reflectors could be built around - and at last we had an efficient source perfectly set up for beam manipulation (again, search for Ã¯Â¿Â½hqi-t 70wÃ¯Â¿Â½ and see the image under Ã¯Â¿Â½shopping results).

And its at this point that fittings such as iGuzziniÃ¯Â¿Â½s KRISS was introduced to the market Ã¯Â¿Â½ and very funky it was, too. And this was followed by lots of other ways of getting light out of a box on a wall. The only thing that couldnÃ¯Â¿Â½t be affected was that old thing about light travelling in straight lines. If only we knew what was about to happen Ã¯Â¿Â½Ã¯Â¿Â½.

Modern building forms are influenced by the way that thereÃ¯Â¿Â½re put together, so the steel frame thatÃ¯Â¿Â½s concealed behind most facades determines whatÃ¯Â¿Â½s solid (a wall) and whatÃ¯Â¿Â½s transparent (a window). As a consequence you tend to find vertical lines of brickwork betwixt the windows and horizontal spandrels or something running tÃ¯Â¿Â½other way.
No one seemed interested in illuminating the horizontal plane of a modern building Ã¯Â¿Â½ go on, take a look outside if you donÃ¯Â¿Â½t believe me.
But if you have lots of these vertical solid sections then these types of light fittings were the obvious choice, especially to the unimaginative.

And then there came the LED:
If you have a tiny light source that can be made into al sorts of shapes, from a ribbon of light to a tiny light button, then you can change the shape of light on a building. The building form can be exploited in whichever plane you fancy, and you can even make the entire building light up Ã¯Â¿Â½ if you have the budget. (try the search for Ã¯Â¿Â½building light images Ã¯Â¿Â½ and be amazed)

Originally, LEDs didnÃ¯Â¿Â½t have the power to project their light in the way that a conventional spotlight does, so the idea of using LEDs as a kind of illuminated mosaic tile was a genuinely new approach to lighting. Perversely, as LEDs have become more powerful, weÃ¯Â¿Â½ve started to fall back into those bad old ways of lighting Ã¯Â¿Â½ using projected light to create our lighted scenes (yawn) Ã¯Â¿Â½ where sometimes it works, sometimes it doesnÃ¯Â¿Â½t.

LEDs work best when they can be woven into the fabric and patterning of a building Ã¯Â¿Â½ not when they are just bolted on to the faÃ¯Â¿Â½ade like an afterthought.

Now whether we should be burning energy in this flamboyant fahion is open to debate, especially at a time when energy costs are spiralling and local authorities are being forced to consider reductions in their street lighting provision. ThereÃ¯Â¿Â½s probably sufficient justification right there for a follow-up piece to this one.