[jambutty]

Originally Posted by entwisi

I must say that the figures I've seen always quoted 10X lifespan.

No ones mentioned the mercury yet................

Me too entwisi, I’ve always heard 10 times quoted by those who are trying to encourage us all to go down the LE road.

However according to the packaging on a General Electric LE bulb (normal price £3.50 reduced to £1.75 at Asda) on side of the box it quotes; “Lasts 6 years, if used for 2.7h per day.” Thus ignoring leap years, 365 x 6 x 2.7 = 5913 hours. Near the bottom of the same side it reads: Last longer – 6 times longer than normal bulbs. I still prefer classical cousins to normal bulbs. It also states: Saves energy – uses 80% less electricity.

Interestingly this particular 15w LE bulb is sold as an equivalent to a 75w classical cousin and the box also quotes the lumens. 799Lm for the LE and 820Lm for the classical cousin. Not a huge difference and probably not discernable by the naked eye but it doesn’t fool a solar panel on a calculator. So if proof were ever needed that an LE bulb does not give off as much light as a normal bulb General Electric has supplied it.

The box also reveals that the LE bulb should not be used in conjunction with a timer or dimmer switches. Why not a timer I wonder? The box also goes on to declare that an LE bulb should not be used in “enclosed or recessed fixtures” because it could reduce its life. That’s about all of the fittings in a house if you include lampshades. LE bulbs are looking less of a bargain than is being claimed.

The 60w hot filament bulb box reveals that it delivers 700 lumens for a life of 1,000 hours. It also declares that the bulb is fused for extra safety. That would explain that every time that the bulb dies it always take the plug fuse.

However a rated 60w LE bulb (actual 11w) from Philips lasts for 6 years according to the box and uses 5 times less electricity to operate. I measured the current of the 60w normal bulb and it was 200mA whereas the current drawn by the LE bulb was 20mA. On the top of the box it states 6,000 hours, 600 lumens, 80 mA. 80mA? Maybe my multimeter is dicky? But to be so far out? It is unlikely. So there again if proof were ever needed, an LE bulb gives off less light than a normal bulb. And that is what I stated at the outset and did so on the observation that my calculator had to be brought closer to the source for a LE bulb than for a normal bulb for it to work.

P.S. I don't want to talk about mercury arc lights.