CFL RO 80 style

[Dave Plowman (News)]

Just why are these so expensive? 13 quid in B&Q...

[Andrew Gabriel]

I presume you are refering to the 23W GE Genura?

The price of these has simply never dropped, unlike all other compact fluorescent retrofits. These were a new technology when they were introduced some 10 years ago -- they are electrodeless. Since failure of fluorescents is most commonly due to failure of the electrode coating material, that mode of failure is avoided and they last much longer. Also, the losses associated with the extra voltage drop at the electrodes is eliminated, making them more efficient. When these were introduced, they were the only compact fluorescents which were brighter than the lamps they intend to replace whilst also being barely any larger. This might still be the case even now. These lamps will carry on running until either the control gear dies (a random effect, but dependant on running temperature), or the phosphor wears out and the light gets too dim to be viable. I had about 50% still running after 20,000 hours, back when they only claimed a life of 8,000 hours, although they were noticably dimmer than new ones. Last time I noticed, GE were claiming a life of 15,000 hours on the boxes.

Having been one of the pioneers of electrodeless lamps, GE mysteriously stopped developing them after releasing this first product, but has nevertheless continued manufacturing the Genura. They would probably sell a lot more if they dropped the price, but I'm sure if you do the calculations, the lamp is still well worthwhile.

BTW, it's a flood lamp, not a spot lamp. It has quite a prononced run-up, starting at something like 50W equivalent light output, and increasing to over 100W equivalent in a minute or so (although I haven't bought any for ages, so this might have changed). Also, there's no switch-on penalty on lamp life -- you can switch it on and off as often as you like.

There are folded tube R80's aroud now of course, but I don't think any of them match the Genura's efficiency, light output, and size match to a real R80, although some might have slightly more directional beams.

[meow2222]

The electrode ones are pricey too, =A38 for screwfix's 2nd rate offering. Inferior light level, larger than standard R80, and comes on fairly dim. Last time I saw the Genura it was over =A320 as well.

NT

[Dave Plowman (News)]

Yup.

[snip super explanation]

I have an RO80 in an ancient imitation TV type lamp which came from Habitat and has barn doors - so ideal for just lighting the keyboard without spilling on the screen. But the bulb seems to blow every other month. The 15 times + life seemed attractive. Perhaps I'll treat myself to a Xmas present. ;-)

[Andrew Gabriel]

One other thing -- they are not available in 2700K. They are manufacturered in 3000K and IIRC 3500K. The 3000K will appear slightly cold when mixed with filament lamps. I don't know which colour temperature B&Q stocks.

[Dave Plowman (News)]

Don't think that would be a problem - I don't use it with the room lighting. And a nearer match to the monitor would be no bad thing.

[Andrew Gabriel]

Yes, they have been up at that price in B&Q.

When I first bought them, they were £11.50+VAT in boxed quantities (which was only a tiny bit more than other retrofit compact fluorescents at that time). The price climbed a little after that, but does not seem to have changed a lot. Certainly they haven't dropped in price the same way other retrofit compact fluorescents have over the last 10 years.

[Dave Plowman (News)]

Well, I've just bought one. Just under 20 quid. Colour temperature 2700k. Even at a room temp of 20C it starts at near zero light output but quickly comes up to full. Quite restful, really. ;-)

I hope I live long enough for it to pay for itself. It says it's 80% efficient.

[meow2222]

re Genura...

Not a chance - the ballast might be, but the lamp as a whole no way

NT

[Andrew Gabriel]

Indeed, I can't imagine what that means. The phosphors in fluorescent lamps are only around 50% efficient to start with.

re 2700K -- that's good to know. They didn't use to do it.