New bulbs. - Page 7

jambutty · 13-03-2007, 12:48

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I'd also expect the Energy saving bulbs to be far more cost effective. Assuming that we leave both bulbs on for 10,000 hours, we'd need to buy 10 incandescant bulbs and one Energy saving bulb. Taking the price of an incandescant bulb to be 50p and an energy saving bulb to be £3.50 we've saved money already without even considering the electric bill!

Your argument would be right except for one tiny detail DeShark. Of all the LE bulbs that I have seen they all claim a lifespan of SIX TIMES that of a normal bulb not TEN TIMES as your example shows. Thus if you used both types for 60,000 hours you would need 60 normal bulbs at 50p = £30 or 10 LE bulbs at £3.50 = £35. So with regard to purchase price the LE is not as cost effective as you so eloquently put it, as their classical cousins. (Nice phrase that.) Undoubtedly the running costs will be about a tenth of those for a normal bulb and some of that would off set the purchase differential. Then you have to look at how many lights are on and for how long in the average household, if there is such a thing. In reality the overall saving per quarter would be negligible in the spring, summer and autumn months, because apart from the stairs light and a kid’s bedroom most lights would not be used and not very much during the winter time. So as far as the domestic lighting scene is concerned using LE bulbs will not a have much of an impact on saving electricity. There will be some, yes, but not as much as the hype would have us believe.

entwisi · 13-03-2007, 12:53

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

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

andrewb · 13-03-2007, 13:00

Jambutty, do you accept the physics behind my post informing you about the different frequencies that can be used with solar cells and hence the reason why your calculator dosn't work with LE bulbs, rather than it being less bright?

DeShark · 13-03-2007, 13:00

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Originally Posted by entwisi

Global warming may not be a fictional device but the 'evidence' that it is us that is causing it is not as yet proven.

Oh come on. Scientifically it's hard to prove a correlation such as that due to the number of possible factors. But carbon dioxide levels rose drastically in the late 19th and the 20th centuries. Carbon dioxide being a gas that contributes to the greenhouse effect. At the same time there was a peak in global temperature. Is it just a coincidence that this coincides with the industrial revolution and the burning of fossil fuels? Perhaps aliens began to inconspicuously deposit vats of CO2 into the atmosphere. I somehow doubt it. It's obvious to all but the ignorant that we are the cause of the problem. Even if we aren't, we still need to do something about it if we want to conserve our way of living. Reducing the amount of CO2 will help with this. Please stop ignoring the problem in the hope that it will go away. I'm not trying to point the finger. I'm as much to blame as anyone else. I'm just saying that there is a problem and it needs acknowledgement before we can solve it.

http://www.classzone.com/books/earth...u501page04.cfm

jambutty · 13-03-2007, 13:39

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Originally Posted by DeShark

P.S. The blue bulb will permit infrared emission to occur. Just touch the bulb to see how hot it gets. This heat will be radiated and used to power your calculator explaining why it works. Your lighter also emits infrared radiation as will your computer screeen.

Very true but how much heat does a torch with a blue filter over the lens produce that can have an affect on my calculator? Undoubtedly some infrared will filter through as well as will other spectral colours because the blue filter is unlikely to be a perfect blue.

The bottom line is that my calculator will be activated by light from any source and it is the brightness (or amount measured in lumins) of light falling on the solar panel that will determine at what point the calculator will become operative. Where the light comes from or what colour it is, is irrelevant. The blue end of the spectrum has more energy than the red end and therefore I conclude that more energy means a brighter light. With a 10% differential between the outer limits of the spectrum as shown by http://www.iee.cz/iwtpv04/6-Pociask.ppt slide number 32 it is hardly a major factor.

In any case the point being made applies to, presumably, a modern solar cell. My calculator is more than 20 years old.

entwisi · 13-03-2007, 14:01

Quote:

Originally Posted by DeShark

Oh come on. Scientifically it's hard to prove a correlation such as that due to the number of possible factors. But carbon dioxide levels rose drastically in the late 19th and the 20th centuries. Carbon dioxide being a gas that contributes to the greenhouse effect. At the same time there was a peak in global temperature. Is it just a coincidence that this coincides with the industrial revolution and the burning of fossil fuels?

Strangely enough Nature is absolutely full of seemingly impossible co-incidences, without one of which we wouldn't be here ourselves to chat about it. We have proven nothing except a coincidental set of circumstances which someone wishes for whatever reason (political, religious, financial, who knows) to link together.

There's statistics and theres life. I know whos side I'd bet on

jambutty · 13-03-2007, 14:34

Quote:

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.

Neil · 13-03-2007, 18:50

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Originally Posted by jambutty

It also states: Saves energy – uses 80% less electricity.

Argumentatively you could say that because of the heat given out by using incandescent lamps you wont need to burn as much fossil fuel to heat your house. Anyone fancy giving us a nice equation to work out the difference in heating fuel need by house A using fluorescent lamps and house B using incandescent lamps?

Neil · 13-03-2007, 18:53

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Originally Posted by entwisi

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

That is why I mentioned the disposal by licensed contractor in the workplace. HBC will have to have a compact fluorescent collection service unless they want us landfilling that mercury

andrewb · 13-03-2007, 19:12

Quote:

Originally Posted by jambutty

Where the light comes from or what colour it is, is irrelevant. The blue end of the spectrum has more energy than the red end and therefore I conclude that more energy means a brighter light. With a 10% differential between the outer limits of the spectrum as shown by http://www.iee.cz/iwtpv04/6-Pociask.ppt slide number 32 it is hardly a major factor.

In any case the point being made applies to, presumably, a modern solar cell. My calculator is more than 20 years old.

More than 20 years old? Then this proberbly applies even greater because its only with recent times that they're getting more efficient and using more of the spectrum.

Unless you can prove otherwise, stop denouncing scientific fact. The colour of the light DOES matter. It explains EXACTLY what is going on and why your calculator works less well with LE bulbs even though they're the same brightness. How can you just conclude otherwise going against physics, unless you happen to have proof.

It is a major factor, it is the single factor that explains why your calculator works differently under two bulbs (of the same brightness).

Ps. Your whole assumption that 'it has more energy so it must be brighter' would mean LE lightbulbs are actually brighter than normal ones so don't prove yourself wrong in the same thread.

Just accept science. For once.