Sunday, February 28, 2010
Down with Uplighters
Up-ligthers have, probably quite rightly, a reputation for being a very inneficient form of lighting. I thought I would share with you a 1 hour project I undertook last year to radically reduce the carbon footprint of our humble up-lighter. As we live in rented accommodation we were not keen to spend huge amounts of money on light fittings for our forty square meter lounge. Instead we bought ourselves a dimmable halogen up-lighter which provided a nice light that could change with our mood and which we could take with us when we moved. Being a large room we had to have quite a powerful light and the up-lighter we chose used a 300watt halogen bulb. We use it virtually every evening for 3-4 hours so it probably accounts for 10% of our lighting bill single headedly.
In September last year I was walking through our local DIY superstore when I spotted some GoVenA 20W dimmable compact fluorescents on special offer and immediately got the idea of replacing the halogen bulb with two of these. [I should say at this point that I am a qualified electrical engineer, but I don’t think that this kind of project is particularly difficult for an average Do-It-Yourselfer with reasonable knowledge of electrics]. In the same store I was able to purchase two bulb holders that came with a screw mount.
Once home I disconnected the lamp and started to remove the halogen fitting. The up-lighter sits on top of two twisted copper tubes (see above picture). One tube carries the live and the earth wires while the other carried the neutral. The halogen lamp was strung between them. Luckily on the fittings there was a screw fixing for part of the halogen lamp assembly which I could use to mount the two new eddison screw fittings. The only thing that remained was to take a live feed wire to the other side fitting and vice versa for the neutral. The earth wire remained connected to the metal part of the lamp (see picture, right for finished assembly). The whole exercise took around an hour and worked perfectly and safely. Actually, as it produces so little heat, its probably safer than the original [HOT!] lamp.
The twin 20W bulbs are easily as bright (if not brighter) at maximum brightness as the 300W halogen was, but uses just 13% of the electricity. If, as I assume, this one fitting consumed 10% of our lighting power, which In turn is 10% of the electricity we use and that is 20% of our total household energy consumption then I saved 0.17%1 of my total household energy consumption for a cost of around £40. Better still the light spectrum coming from the bulb is cleaner and whiter than the original halogen bulb and the spectrum remains the same as the light is dimmed. According to the GoVenA website the lamp can be dimmed to 2% of full power – or just 0.4W per bulb! These bulbs are extremely efficient even compared to other compact fluorescents. FYI I found two YouTube videos of a similar bulb here and here.
1This is not quite true in winter as, ironically, the heat produced by the halogen lamp did mean that the central heating system had to work less hard. However electricity does produce much more CO2 than natural gas for the same heat output so the carbon saving is still significant.