LED replacements for Halogen downlights - ISSUES

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Re: LED replacements for Halogen downlights - ISSUES

Postby EnergyMatters » Tue Dec 29, 2009 6:41 pm

AG73, Is it just a coincidence that the email address you registered with seems to have the same first initial and surname as one of the people behind the company you gave such a positive review about? It's a fairly uncommon surname too.

We really don't appreciate merchants posting positive reviews of their own business while posing as customers of that business. It's not only a breach of our forum guidelines, but just very poor practice that can actually backfire on a merchant as it is simply just deception - word regarding this sort of behaviour tends to get around. I believe there's also laws against this type of thing.

However, rather than playing judge and jury, perhaps there's another explanation you may like to offer. I sincerely hope I am mistaken, but we've had this happen quite a bit on our forums and we don't like our members being misled.

I'm putting a ban on your account in the meantime while we sort this out, if you wish to follow up on this, you can contact me at forum.admin@energymatters.com.au.
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Re: LED replacements for Halogen downlights - ISSUES

Postby taggertycyclist » Tue Dec 29, 2009 7:18 pm

At least someone like zzsstt is thinking, and doing the calcs. And highlighting the murkiness of all this hype about "green" alternative energy usage and devices/gadgets to "save the planet" that I alluded to in another thread in Introductions. Of course, all this is in light of the ban on the sale of incandescent globes that is supposed to come into being in a couple of days' time.
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Re: LED replacements for Halogen downlights - ISSUES

Postby zzsstt » Wed Dec 30, 2009 12:20 pm

taggertycyclist wrote:At least someone like zzsstt is thinking, and doing the calcs. And highlighting the murkiness of all this hype about "green" alternative energy usage and devices/gadgets to "save the planet" that I alluded to in another thread in Introductions. Of course, all this is in light of the ban on the sale of incandescent globes that is supposed to come into being in a couple of days' time.


It doesn't pay to think too much. If you start thinking, you start questioning. If you start questioning, you start investigating. That's when the trouble really starts....

We are banning incandescent globes (power factor 1) and replacing them largely with CFLs (power factor 0.5 ish). We think we are doing a good thing. Overall we may well be, but by a much smaller margin than we think!

The low PF of a CFL (I've measured the latest Philips Tornado's as 0.55) means that although the globe is "12W", it's actually drawing 22VA. The 60W globe it replaced was pulling 60VA (pure resistive load = unity power factor), so the power saving is 63%, not the 80% that is claimed. Of course the domestic use only pays for the actual power (12W) but the grid needs to generate (and thus emit CO2 for) the full 22VA. I have read, but not personally tested, that a CFL connected to a dimmer switch may result the power factor decreasing still further, perhaps to the mid 0.2's. So now the 12W CFL is taking 48VA to run and only saving 20% of generation. Of course it says on the CFL packet that it won't work with a dimmer, but it requires an expensive electrician to remove the dimmer, and in fact the CFL will most likely work if the dimmer is left at "full on", and I'm guessing that many will be used this way.... except that the CFL is now only saving 20% and feeding some really nasty harmonics in to the supply.

Then add the harmonics that the CFL causes in the supply (even without a dimmer!), and factor in a reduced life and performance for everything connected to the grid as a result.... unless you buy a mains filter of course... k'ching!

As the power factor is reduced, the current required is increased. Power loss in distribution is a result of current. So the grid now has to generate power that it cannot charge for (it supplies VA whilst domestic users are charged for kW's) and the higher than needed current means higher distribution losses. This means that whilst the CFL box states an 80% power saving, and the domestic consumer may even see an 80% decrease in cost to run that light, the savings in the amount of power generated are nowhere near that much - so the emissions are not reduced to anywhere near that amount. And because the power company has to generate and supply all those unchargeable VA's, they'll want to recoup those costs somewhere along the line!

But at least the 5mg of mercury in a CFL is "probably" only toxic to infants and pregnant women, not cynical middle aged b*st*rds like me!
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Re: LED replacements for Halogen downlights - ISSUES

Postby bradley.jarvis » Tue Jan 05, 2010 10:08 am

I reckon the real scam is the people who come into the house to replace all your globes for free with CFL's. First of all 'nothing is free' and secondly you 'pay for what you get'. Cheap CFL's and cheap LED lights are just that. They don't last and they give poor performance. At the end of the day the bad/cheap product turns people off using them. We had CFL's that we bought early on before they started to become popular and most ran for upto 7 years (we sold the house that we used them in). We did find that some of the newer cheap ones died very quickly.

But this is like so much stuff that is sold. It just is not made to last, and that is represented in the warranties that companies give on a product, usually 12-24 months. A product that only lasts a year no matter how efficient over all when cost of energy in production is taken into account is not green. I personally would not buy led products off ebay for instance because it is too hard to filter the cheap crap out from good product.

We use XCree based 3W 12VAC lights run straight off our 12V battery bank, we find the brightness sufficient to read under at night (they would make a brilliant spot light). Our total power consumption per day at the moment is ~2kW

Thanks, Brad
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Re: LED replacements for Halogen downlights - ISSUES

Postby taggertycyclist » Wed Jan 06, 2010 7:21 pm

I read with interest an article (on news.com.au) that said a power company in Germany had distributed an inordinate number of CFLs (in the multi-millions) to its customers to offset its supposed imprint. Research has found that the vast majority of the globes weren't used, but instead were stuffed away in drawers and forgotten, or put out with the garbage.
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Re: LED replacements for Halogen downlights - ISSUES

Postby SR76 » Tue Feb 23, 2010 11:00 am

Well...

I am going to withdraw my previous endorsement of the Iogear 5W leds as:

1) After ~ 18 months of operation, one of the five I installed started blinking on and off
2) Even if they were on for 24 hours a day, that would amount to 13,000 hours. The box says they're good for 50,000. At 4 hours a day (probably still an over-estimate) that's only ~ 2000 hours.
3) Google can no longer find Iogear LEDs on the web any more.
4) Out of curiousity I plugged in a 20W Osram halogen bulb to compare light output with the surviving LEDs. It was considerably brighter. Back when I bought them I knew they were going to be less bright than the 50W bulbs they replaced but I never attempted a direct comparison.
5) I left the 20W bulb in parallel with 2 of the 5W leds (probably a bad idea), and after perhaps 30 minutes looks like I popped the transformer.

So... on the weekend I did what I should have done 5 years ago when I bought the house... rather than complaining about the downlights that were there when I bought them, I pulled out all the fittings and replaced them with a single battenholder and an 11W Osram CFL. Which works WAY better.

Never again.
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Re: LED replacements for Halogen downlights - ISSUES

Postby SR76 » Tue Feb 23, 2010 11:02 am

By the way... out of further curiosity I bought a Mirabella LED downlight from Coles, with very low expectations of success. It has 15 individual LEDs in an MR16 shell and draws a total of 1.1W.

Joke.

Coles do refunds, by the way.
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Re: LED replacements for Halogen downlights - ISSUES

Postby jhamill » Wed Mar 10, 2010 12:37 pm

SR76 wrote:By the way... out of further curiosity I bought a Mirabella LED downlight from Coles, with very low expectations of success. It has 15 individual LEDs in an MR16 shell and draws a total of 1.1W.

Joke.

Coles do refunds, by the way.


how did your experiment go? I bought one of their GU10 (I think) for a 240v light replacing a unit in my rangehood. not as bright as a CFL one in there, but quite acceptable.
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Re: LED replacements for Halogen downlights - ISSUES

Postby SR76 » Wed Mar 10, 2010 1:41 pm

jhamill wrote:how did your experiment go? I bought one of their GU10 (I think) for a 240v light replacing a unit in my rangehood. not as bright as a CFL one in there, but quite acceptable.


I would say that rangehoods might be one of the few applications they may be suitable for (my rangehood lights are way too bright, and seem to be permanently affixed, would need an electrician to replace them properly?). I found it to be extremely dim even compared to the other LED lights (but hardly a surprise when the total power draw is 1.1W) and certainly not suitable for ceiling fixtures.

They could be quite useful for night lights, small reading lamps or other little uses like that - however most of these don't use MR16 / GU5.3 fittings anyway.
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Re: LED replacements for Halogen downlights - ISSUES

Postby jhamill » Tue Mar 16, 2010 9:29 am

SR76 wrote:
jhamill wrote:how did your experiment go? I bought one of their GU10 (I think) for a 240v light replacing a unit in my rangehood. not as bright as a CFL one in there, but quite acceptable.


I would say that rangehoods might be one of the few applications they may be suitable for (my rangehood lights are way too bright, and seem to be permanently affixed, would need an electrician to replace them properly?). I found it to be extremely dim even compared to the other LED lights (but hardly a surprise when the total power draw is 1.1W) and certainly not suitable for ceiling fixtures.

They could be quite useful for night lights, small reading lamps or other little uses like that - however most of these don't use MR16 / GU5.3 fittings anyway.


and the other benefit of LCD/CFL in the range hood is that the heat produced is minimal. the halogen that was there before used to cause the stainless around to be 'roasting'. in my case you don't need an electrician to replace the lights - just remove the filters and the lights can be changed easily.
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