A question that pops up regularly when I’m speaking to my clients is ‘what’s happening to light bulbs, then?’ So let me talk about light bulbs for a moment. For the best part of the last century it meant the 60W light bulb. I really should give it its proper name: it’s a 60W GLS tungsten filament lamp. Bulbs are what get planted in gardens (ho ho), so I’ll be calling them lamps, otherwise I’ll come out in a rash. But – whatever it’s called, we know what it does.
There’s one serious problem with a filament lamp – its not very efficient in turning electricity into light. Here’s a number for you; a tungsten lamp produces around 10lumens/Watt (‘lumen’ is just the measuring stick we use to quantify the illumination coming from a light source . . .its not really a stick). We need to do better.
The first real energy crisis in the UK came in 1973, when we found out what happens when raw fuel doesn’t get delivered to power stations . . . the lights go out. So it became very important to be more efficient in our use of energy. And that is far truer today – albeit for a different reason. Today we have the very real challenge of climate change to face and all that may come with it.
So: what’s to do done with the light bulb – – er, lamp? As it happened, while we were sitting in the dark in the mid-1970s the first compact fluorescent lamps (CFL) were coming out of the labs and into the factories. At the time, none of us imagined that these strange looking objects with their spiral tubes and double-barrel stick arrangements would ever be available in the local supermarket, but that’s what’s happened, to great success. And, most importantly, they are far more efficient, delivering over 60lumens/Watt, making them the obvious successor to a light source that hadn’t changed very much in the century since Edison and Swann invented it.
Ah, but hang about –what are these LEDs that everyone’s talking about? About ten years ago, a new way of making light started to make its presence felt in the lighting industry and articles like ’Will LEDs Ever Take Over Lighting’ started to appear. We now have an answer to that question: yes, they most certainly have. And this has become a very real problem because the traditional lamp manufacturers have been left reeling by a flood of new LED lighting product. There are no standards and no conventions to adhere to, and that’s brought a lot of customer confusion and dissatisfaction. Not to put too fine a point on it, a lot of the LEDs on offer are rubbish – the problem is in the sorting-out of the good stuff from the rest.
So how do we know what to buy? Here are a few tips for you. I hope you find them useful.
1. as a principle, don’t buy on-line unless you already know the product that you’re buying.
2. buy from a shop with a reputation to lose; they tend to be more careful in what they sell.
3. Read The Packaging! The lamp colour should be 2700Kelvin; the light output (equivalent to a 60W GLS lamp) should be 600lumens; the expected life term should be given (10000 hours for a CFL and up to 50000 hours for an LED, for example). LEDs may – or may not be dimmable. CFLs will almost certainly NOT be dimmable.
Oh, by the way; I realise that I’ve only been talking about the trusty old ‘light bulb’, while so many of us have invested in tungsten halogen downlights and spotlights. I don’t have the room to deal with those in this piece so will talk about the confusion going on with replacements for reflector lamps the next time I write.