There has been a lot of discussion on this group about tungsten- replacement lights. The long thread on this subject ("100w light bulbs") does not seem to reveal much enthusiasm for CFL's.
How about LED's? I have less experience with those, but what experience I have suggests they are blinding white to look at but without a decent light penetration. Are there positive experiences out there ?
LED's too do not seem to be realistic tungsten/incandescant replacements. Seems we are banning petrol/diesel cars before the fuel cell is ready, if you see what I mean.
high efficiency long lived, but not as long as often claimed low light quality (CRI and CCT both not good) low max light output per lamp very robust high purchase cost, with cost apx proportinal to power
Ideal for apps requiring robustness and low light output, eg inspection lights.
LEDs share some, but not all, of the problems of CFLs. They are either monochromatic (red, green, orange, blue) or ultra-violet with a phosphor mix on the front to approximate to white light. At high output powers, the light emitting part gets warm enough to drop in reliability, so rather than one big LED, lamps are currently made with several smaller LEDs in an array. Their light output is highly directional, so to replace GLS lamps you need effective diffusers (which are quite difficult to get right).
As I said, the 'white' LEDs use a phosphor coating on an ultra-violet (or occasionally blue) LEDs - this has the same problem with colour rendition as fluorescent lamps, which use the same excited phosphor mechanism - in the case of standard and compact fluorescent, the excitation is by ultra-violet light generated from a a mercury arc discharge.
By using a different coloured LEDs and varying their output, almost any perceivable colour can be generated, but the luminous efficacy (lumens/watt) of such set ups is poor, as is the stability. Phosphor coated uv- or blue- LEDs can now better standard fluorescents in luminous efficacy.
Leds are getting better but are not ready for prime time in the US as far as cost, lumen, and color is concerned. I just bought a few and will return them since the package ratings were untrue on output. They are getting more efficent and better color rendition but are not what I have seen any more efficent than Cfls or as good a color. We have Cfls here that have a better color rendition then incandesants, there is an old rating at
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' Popular Mechanics magazine, I dont know if my link is correct but its in the home section of maybe 1 yr old. Leds I will wait on, my Cfls have 7 yr walk in warranty and cost me 1$ US.
Yup. Greenpiss have done more damage to the actual environment by making such ridiculous claims and coming up with such ridiculous solutions that they have made people suspect that global warming ain't happening. Its 'just a ploy by manufacturers to sell more expensive rubbish'.
But the real problem was the European lightbulb manufacturers who lost their GLS business to China, so 'fixed' a bit of trade restriction by the back door, 'persuading' them to ban GLS in favour of the much more profitable CFLs.
On Thu, 08 Jan 2009 08:44:35 GMT someone who may be "The Medway Handyman" wrote this:-
An excellent example of what I was talking about.
A lot of FUD has been spread about compact fluorescent lamps, generally by those sections of society which whine about anything different. Unfortunately some people are taken in by these allegations. However, no matter how long and loud the false allegations about them are repeated they will remain false, as those of us who have used them since the 1980s know and will occasionally say, despite attempts to shout us down.
Over that period it has been interesting to watch the developments. The compact fluorescent lamps I bought in the early 1980s did take a long time to start, were bulky and heavy, and so on. However, that was a long time ago and engineering has moved on since then.
The Daily Wail inspired stampede to buy Swan-Edison lamps is great, the sooner they are removed from the shops the better. I look forward to the Daily Wail inspiring similar panic buying of 60W lamps. As Mr W says from time to time, bring it on.
It depends. What we know as white light is a combination of all colours. LEDs tend to produce a narrow spectrum light and even by adding what appears to be the three primary colours won't necessarily give a pure white. What tends to make non filament light look poor is not any slight tint it gives to things - but what parts of the spectrum it is missing.
Some prefer lighting in the home to help make the mood in a room - not just illuminate it for the hoovering. And CFLs are totally useless for this. Not much better for the hoovering, either.
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