The trouble with any sort of bandwagon – black tulips, South Sea Bubbles, dotcom booms, sub-prime mortgages bundled up as security bonds, or even something as noble as saving the planet – is not that they all start with some vague, mythical semi-science, but that they are sold to the rest of us gullible earth-dwellers by ardent believers. When it all falls apart at the seams, we sit down and work it out properly for ourselves, as we should have done at the beginning. When we realise that we were told that two plus two equals five by a man who patently can’t add up, it’s no wonder we chastise ourselves.
BEWARE OF FREE GIFTS:
The world of interiors is currently undergoing its very own version of mass hysteria – all the talk is now of low-energy lighting, and we have already been through the first wave. Is there a household in the country that has not had a free CFL (compact fluorescent lamp) sent to replace those archaic GLS ‘enemies of the state’?
LESS THAN CLEAR:
Those who have diligently used them, rather than sensibly placing them in a cupboard for a rainy day, find that they provide users many moments to contemplate the meaning of life – while they wait for enough light to emanate to be able to walk into a room without stumbling into furniture their kids have moved to create more room to flail around with their Nintendo Wii. You note that the room is darker than usual, because distracting reflections on the TV screen require the curtains to be permanently closed. You might also notice that the family gathered round for tea have lost the rosy glow they had under incandescent light, and now look rather pale and sickly, and that the nice walnut sideboard grandma left you suddenly looks a bit plasticky.
However, don’t get too excited because the guys pushing these things are enthusiasts at the Department for Environment, Food and Rural Affairs, and they’re having a change of heart – ‘Oh, my. These CFL thingummies have mercury in them. Heaven forefend, take them out.’ The fact that if you broke a thousand of them into a fish tank it would leave your poor pink friend only slightly perturbed by the shards of glass and your state of mind has passed the Defra minister by – but then he is only an amateur, after all. The trouble is that the next big thing they are going to push is LEDs, and these people still haven’t improved their science skills.
But interior lighting design is a serious matter, and nothing is more serious than designing a scheme to be efficient with the energy it uses. We have learned how good lighting can transform interiors and public spaces, and we know that lighting affects health and even productivity. No one is suggesting that lighting, or any other energy use, should be reduced to the strictly utilitarian – we can’t all go to bed when it’s dark and only have hot food once a day. Aesthetics are at the core of human existence – we have created objects of beauty since men drew on the walls of caves 14 000 years ago – so it is up to us to use our intelligence and acquired science to make life pleasant, as well as energy efficient.
By the same token, we know that the problem is not answered by a craze for a magic ‘one stop’ solution to all interior lighting needs. If a man shines something bright in your eyes and tells you that this 4W LED will do everything that, five minutes ago, a 50W halogen did excellently, it probably sounds unbelievable, so beware. Research and development budgets in the major lighting companies around the world are being pushed into many technologies to create and control lighting. Dimming, presence detection and daylight-sensing systems alone can save massive amounts of energy, and fluorescent lamps still represent the most efficient, as well as the most economical, light sources available. Cold cathode, metal halide and, of course, LEDs all bring their own particular features to the low-energy lighting tools cabinet.
LED-ING US ASTRAY:
Once upon a time, the correlation between power consumption and light output meant that, if a 60W lamp was to be hung in the middle of a room, everyone would understand that they would be able to see their way around it. The way that LEDs, in particular, are developing now means that power consumption cannot be relied on to give us the information we need.
First, the numbers are much smaller (typically between 1W and 7W). Second, there are huge differences in performance. And third, light output varies with temperature (some LED manufacturers publish light output data at 0°C, which isn’t very helpful – it can be 30 per cent lower at 250°C). We have to resort to lumens (which is the light output) and lumens per watt, and get used to what those figures actually mean to get a feel for what is going on. It might help you to know that our old favourite, the 60W GLS lamp, emits 710 lumens.
So, like it or not, from now on lighting is getting much more technical and we’ll all have to don our science caps, sit down, investigate the facts and do the sums – and everybody, please, remember that there really is no such thing as a free lunch – in science or the City.
Sponsored by Lightgraphix