On Sun, 11 Nov 2007 21:14:28 +0000 someone who may be Andy Champ wrote this:-
Some people are either trolls, or sceptical of anything new (for whatever reasons). When I mentioned the new wiring colours one of the usual suspects rushed to condemn them in loud terms, but was unable to come up with any other scheme which would meet the requirements. They simply wanted no change, if their postings were to be believed.
Such people are mildly amusing and on rare occasions contribute something useful.
The ones with an IR reflective coating are very difficult to find in the UK. They would appeal to people keen on energy efficiency, but those people are less to be using halogens in the first place, so there's almost no market for them here. Occasionally, B&Q have had the 300W and 500W ones (which are
225W and 375W respectively), but I haven't seen those for a long time now. I haven't seen any of the other styles in the UK at all, only abroad.None get to 40 l/w. The sweet spot depends on power rating, but is higher than 12V. 30-50V is the range for 20-100W halogens. However, halogen downlighters are usually used inapproproately for general lighting, in which case the overall efficiency plummets to be the lowest of just any lighting you'll find.
Manufacturers like to use expensive tubes in SAD lights in order to increase their profits. There's no evidence that high colour temperature or high CRI makes any difference to the effectiveness of the lights. Both increase the price of the tubes, and reduce the efficiency of the SAD light.
Soft tone lamps are painted lamps to give a warmer colour. They are significantly less efficient than regular pearl filament lamps.
Added sci.engr.lighting as crosspost, mebbe somone has the full meal deal on current most efficient halogens.
Lack of education, same people are getting sold CFL`s that don`t meet their expectations. Dimmable CFL`s which knock one of my major personal objections to the things out, have only been available in the UK in the last couple of months. In the US they have been around for years.
Some of the specialist lamp wholesalers will get them but rarely carry them as a stock item.
Still possible to knock a bit off your power consumtion with a high quality lamp like Sylvania 37W LV dichro drop in replacement for 50W lamp.
Sure had seen a refernce to a 40l/W halogen somewhere, thought it was Sylvania but ratings on their IR lamps dont get anywhere close. Best could spot was 38 l/W for a 65W car headlight lamp, and the original link 404s
Education about correct tools for the job would help and MR16s like CFls are not the correct tool for every job. Much as can slag the Americans for being polluting power wasters, the US Department of Energy carries out a lot of research into lighting and expends a lot of effort in making the results available in language even an average consumer can understand. If only the UK and Euro organisations would try and make the same effort.
Increase in cost of lamps is fractional, a 4 quid tube against a quid one, its a not yet well understood area that is ripe for explotation by every snake oil salesman with a graphics design package.Just dinnae start me on the 300 dollar LED SAD lites....
Adam
Adam,
Thanks for the cross-post to sci.engr.lighting. The answer to the question is generally that the IR MR16s have been stagnating at 26lm/W or there-abouts on the market, although there are much higher performing models in labs and ripe for launch. We'll see them before too long.
In contradiction to the post that you sent through (I note that it wasn't your point, however), people who really understand energy efficiency may well opt for IR MR16s over CFLs. With an LOR of .4 on a small aperture CFL fixture and no ability to concentrate the beam in any particular way, 60lm/W quickly becomes inferior to 26lm/W delivered on target, with concentration so accenting actually happens. As such, they can be the best option for energy efficiency.
Availability of spec grade lamps is always poorer to the public than mass-market lamps, but any decent wholesaler should be able to order a case of 10-20 pieces at market price. You just need the part number, etc. In Europe, it's Osram rather than Sylvania, plus Philips and GE who make up the big three, followed by Ushio and some asian manufacturers who are beginning to perform.
HTH.
Thomas Paterson
Are you aware of the effect that power cycling has on the lifetime of electrical devices?
You don't know me. Besides, She decides the decoration.
Andy
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