Niall’s virtual diary archives – Friday 28th February 2014

Friday 28th February 2014: 1.25am.

Here is the next generation of energy saving light bulb! This is an early model "LED filament" bulb and is a completely different technology to the LED bulbs of yore which were basically a cylinder circuit board with some SMD LEDs on it. And by "different", I really mean "vastly improved". The previous generation LED light bulbs were little more efficient than a Compact Florescent (CFL) at about 60-70 lumen per watt, yet cost a lot more and did not cast a wide dispersed beam meaning you got large holes in the room where there was little illumination. In short, they weren't very good, though we had a 3w one in Waterloo for the hall and at that low power level it fitted our needs well, albeit casting a bluish light about as bright as a nightlight. Either way, at 3w you could leave it turned on when you were away, and had enough light to find the lightswitch when you came home which is why I got it.

I tried buying something similar when we moved into Dromahane, but it cast an unnatural colour and died after one day (by the way, NEVER buy anything from www.lightrabbit.co.uk, they supplied a misdescribed product (they claimed it had a warm light, it did not; they claimed it was 4w, it was actually 4.6w written on it) with five year warranty yet refused to answer emails or RMA requests). So I decided to go a bit mad and order direct from China the below bulb. There is a German supplier of these bulbs, and an Australian one. Otherwise, you can't find them in 230v anywhere in the West.

So, as you'll see in the pictures, LED filament bulbs look quite like old fashioned tungsten incandescent bulbs, and in fact the second generation LED filament bulbs coming after mine below look very like tungsten incandescents. Mine below has much earlier generation filaments which are thick and chunky and so can't be strung from a wire lattice - they just stick out like a christmas tree. This, as you can see in the shot of the lampshade, produces a tiger stripe light distribution because the filaments only produce light out their front and backs. The next generation LED filament bulbs arrange their (much thinner and more numerous) filaments in rotated segments, thus solving the tiger stripe problem.

What quality of colour light does it produce? I am extremely pleased with the warm light colour it produces. It feels absolutely natural, in fact, more natural than CFLs some of which blow out their red phosphors in an obvious way in overegging their "warmth". This makes objects in the room look a bit weird and unbalanced i.e. unnatural. This LED filament bulb, like all LED filament bulbs, produces a light very close to sunlight thanks to how they work.

Can this bulb be dimmed unlike CFLs? The quick answer is yes: most LED bulbs can be dimmed, and LED filaments especially so. LED filaments don't have the ballast requirements of previous generation LED bulbs i.e. they produce so little heat they never really get warm and therefore need no heatsink as you can see below. Because they're closer to direct drive, dimming works.

So how bright is it? Well, for a 3w bulb, it is exceptionally bright in my opinion. It is day and night versus the old 3w corncob LED bulb I mentioned we had in Waterloo. The Chinese manufacturer claims 450 lumen which I don't believe, but I would accept 350 lumen (see my photo of my hallway, that is not a dark hallway by any stretch, but it's not quite as bright as a 40w incandescent in my opinion). That suggests 117 lumen per watt, which is about the right amount for LED filament bulbs. Let me put that another way: LED filaments bulbs are about 80-100% more efficient that "normal" energy saving lightbulbs. If you're going to have that light on a lot, that's a big difference.

How much cost? You can get them from Germany for €20 each, dropping to about €12 if you order many at once (look for a shop called led berlin on ebay). If you just want one to try, lightinthebox will deliver you one straight from China for about €15. Remember if you exceed €40 you'll get charged VAT on import, so the German supplier looks very attractive for more than three bulbs at once.

I can't say anything about reliability yet, but so far I am extremely pleased with this new technology. I have, in my hallway, quite literally the light bulbs we'll all take for granted in ten years time, but it's saving me money right now. Quite likely my daughter Clara won't actually recognise an "energy saving lightbulb" as being anything obviously different from an incandescent because they'll look almost the same and act almost the same. Technology has, weirdly, looped back on itself in form and function.