LED replacements for Halogen downlights - ISSUES

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Re: LED replacements for Halogen downlights - ISSUES

Postby SR76 » Mon Oct 05, 2009 2:30 pm

Yeah, I spoke to our local Planet Ark guy, one of his customers was a jeweller who picked the warm white for gold and the cool white for silver.

I think particularly in a commercial application where the lights are going to be on for a long time, it makes so much sense to go for the LEDs if you can.

And... 90% energy cost saving isn't the end of the story:

a) I knew a guy (my old boss) who had dozens or even 100+ halogens all through the house. Remember that a 50W halogen light is also a 40-45W heater and think about why he had to run his air con all day... second order energy cost might be huge as well

b) FIRE! 300 degC operating temperature. These things have burned down a stack of houses, including one former sports star's $2MM mansion in Fremantle.

If I were president I'd be putting these things on the BANNED list, next to black roof tiles, leaf blowers and Hummers.
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Re: LED replacements for Halogen downlights - ISSUES

Postby zzsstt » Sat Oct 24, 2009 4:00 pm

Having tried all the options, my recommendation is the Osram IR 20W (MR16 12V) globes. They give out almost as much light as a 50W MR16 (Osram actually state the 30W version is equivalent to the normal 50W, but I'm happy with the 20W'ers), there is no requirement to change transformers or anything else. They are also cheap, have a long life (stated 5000 hours) and are available in a couple of reflector beam angles. As far as fire risks go, any heat producing item is a fire risk if installed or used incorrectly. Having said that, I use surface mounted light fittings anyway, it avoids any number of issues (fire, breaks in insulation efficiency, sound isolation etc.)

LED's are very expensive for anything that gives a reasonable amount of light, and "reasonable" is still a matter of judgement. They may have low overall energy usage, but if they don't give enough light, what is the point? I also have concerns about their life expectancy, as the stated life is merely a calculation. The reality is that we have no idea how long they will last..... the same calculations tell us that CFL's should last for about 7+ years, but I have yet to see one last more than two or so. As with CFL's the calculated "life" allows an ever decreasing output, the ones I investigated from memory allowed a 30% reduction in light output, so even if they manage to survive to their calculated life expectancy, you would need an additional unit for each pair you originally purchased to still be able to read the paper....

I have been involved in business long enough to recognise "marketing" when I see it, so I asked one of the companies selling "25 year lifetime" LEDs, at nearly $100 each at the time, how long they warranty these devices. 12 months.

I have also had enough involvement with "accelerated aging" and the realities of "mean time before failure" (MTBF) to know that neither mean all that much in the real world. As an example of this, at one point I purchased about 150 identical devices (not related to lighting!) to be installed in sites across Australia. They were from a major manufacturer, and had an "industrial" MTBF stated as many 100,000's of hours. They were installed over a period of about 9 months, and every single one failed at 12 to 14 months of use. The manufacturer, eventually, gave me shelf stock of warranty replacements because the failures were so predictable. A calculated MTBF or expected life, based on statistical analysis of components or short term failure rate of (often) prototypes does not give a true representation of real world life. Of course, had I only purchased a single item, I am sure the manufacturer would "never have seen one fail before"...

For general lighting use linear or circular fluoro's.
For short duration task lighting (kitchen benches etc.) use 20W IR MR16's and switch them off when not in use.
For long duration high intensity lighting that is infrequently switched, use metal halides.
For the edge of decks, aesthetic lights, walkways etc. feel free to use LED's.

The main rules are to provide enough light for the job (do not over-light), of a suitable colour, and to switch them off when not in use. A 20W IR MR16, switched on for 30 minutes whilst I am cooking, uses less power than a 5W LED left on all evening, AND provides more light.

I have no doubt that one day LED's will be the unit of choice, but I don't think they've got there yet. Of course, by then there will be an even better product just being released!
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Re: LED replacements for Halogen downlights - ISSUES

Postby taggertycyclist » Sat Oct 24, 2009 5:27 pm

Thank you for a revealing and very useful reference post.
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Re: LED replacements for Halogen downlights - ISSUES

Postby AG73 » Tue Dec 29, 2009 7:30 am

Hi All,

We've just replaced all our old Halogens with 9watt LED's from XXXXXXXXXXXX (removed by admin - see this post for the reason).

I was a little unsure when we were looking at LED's because we'd heard they weren't as bright as halogens. I bought a 4watt LED from ebay as a tester and it was really dull....I pretty much gave up on the whole idea until someone at work suggested these guys XXXXXXXXXXXX.

The LED's we got from them and put in are as bright as our old Halogens, the house looks fantastic - although I paid two postage from their online store as I didn't want to do the whole order first :) I got 4 in first and tested them, followed by 22 in my second order. I was amazed at how bright they were.

I have MR16 connections, and the globes worked as soon as I plugged them in. I checked the brand of our transformers and they are Osram redback as mentioned in the other post, so these must be pretty popular in building.

cheers
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Re: LED replacements for Halogen downlights - ISSUES

Postby SR76 » Tue Dec 29, 2009 10:45 am

Great feedback - glad to hear a success story.

Which model exactly was it you've installed -

Cree 9W LED MR16 Downlight - Warm White?
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Re: LED replacements for Halogen downlights - ISSUES

Postby AG73 » Tue Dec 29, 2009 11:03 am

Hi SR76,

Yes, the globes I installed were the Cree 9W LED MR16 Downlights in warm white (they didnt have the cool whites in stock when i went there last). They are so much brighter than I expected. So glad all the globe hunting is over lol.

You should check them out if you're looking for some, that site gives next day delivery too.

Cheers and thanks for the reply :)

AG
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Re: LED replacements for Halogen downlights - ISSUES

Postby SR76 » Tue Dec 29, 2009 11:14 am

Thanks...

Follow-up question - do you have each downlight connected to a single Redback transformer, or are they grouped?

If they're one-to-one - do you have any problems with minor flickering at all?

-SR
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Re: LED replacements for Halogen downlights - ISSUES

Postby zzsstt » Tue Dec 29, 2009 11:44 am

That's great to hear.

But as a first post on a forum, full of such enthusiastic praise for a company, with two links to their web site and sharing the same initials as the co-founder of that company (Anthony Gerrits), just makes me wonder....

It's customary to state in such posts that you're not in any way linked to the company....?

Edit:

Forgetting the above for a moment, and looking strictly at the paper specifications, these 9W LED units are quoted as producing 380lm. For a 60 degree beam angle, this calculates back to 450cd which is the same light intensity as an Osram 20W (60 degree) MR16 globe. I have no personal experience with these LED's, but on paper they are equivalent to a 20W energy saving halogen (and therefore a "normal" 35W halogen).

Whilst they are not, on paper, anywhere near as bright as a 50W halogen (which would be expected to produce about 1000cd), I have found that for general lighting it is often possible to replace a 50W halogen with a 20W energy saving halogen, and this would mean that these LED's may well all be acceptable in that situation. I would be doubtful that the would replace a 50W halogen (or 35W energy saving halogen) in a situation that requires intense light (task light) unless the existing 50W's were producing excessive light to start with!

From a cost viewpoint, these LED's are $39 each, where the energy saving halogens are just under $10. Life expectancy of the LED's is quoted at 50,000 hours although this is entirely theoretical. Early CFL's quoted a life expectancy of 7 years and rarely lasted one year, these days they still only last perhaps 3 years maximum, so personally I take the quoted life expectancy as a marketing tool and nothing more. The energy saving halogens are quoted as lasting 5000 hours.

So on paper the LED's cost four times as much as the 20W halogens and last 10 times as long. They use 11W less power. Assuming a domestic situation with the light switched on for 6 hours each day, thats a saving of $4.70 of electricity each year.

Over the 50,000 hours of their "expected life" (22 years at 6 hours/day!) they will save $107 in electricity at current prices. Of course, if they blow up in two years they will have cost $39 capital and saved $9 in power! In order to break even, the LED will have to last for at least 6 years (3 halogens + the power saving). If the lights are used for less than 6 hours each day, the pay back timings obviously increase (at 2 hours / day they save only $1.50 per year!).

On the other hand, assuming the life of the LED is at least "reasonable", and assuming the price of electricity will increase, on paper and price these are the best I have yet seen!

Having said all that, I may well purchase a couple to test. If I do, I will post the light meter results here!
Last edited by zzsstt on Tue Dec 29, 2009 4:01 pm, edited 1 time in total.
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Re: LED replacements for Halogen downlights - ISSUES

Postby Tracker » Tue Dec 29, 2009 3:55 pm

.
I too am looking at LED downers.... For security / courtesy lights.

I knew of the issues with ordinary 12V Halogen power packs, and that Iron-Core Transformers get HOT, and that means - wastes energy.

I went the other way.. I went to EBAY and bought some 12V Switch-Mode computer supplies.. They work just fine and cheep as chups !
I understand that Govt. Specifications for Equipment Power Supplies, demands NO iron Transformers, just switch-mode supplies, as they are so much more efficient.
.
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Re: LED replacements for Halogen downlights - ISSUES

Postby zzsstt » Tue Dec 29, 2009 4:29 pm

Tracker wrote:I understand that Govt. Specifications for Equipment Power Supplies, demands NO iron Transformers, just switch-mode supplies, as they are so much more efficient.


I don't recall the regulations demanding no iron cores, but the MEPS standards do define minimum efficiencies and no-load consumption. The numbers are still not great, especially for the small units, but it's all calculated relative to the power output. The bigger the PSU, the more efficient it must be, so between 25% and 100% of rated loading a "high performance" 1W external PSU must be 50% efficient, a 20W PSU need only be 76% efficient, but 50W+ must be 85%.

Switchmodes can be very good, the latest computer PSU's can run at 90%+ across a large part of their range. However they're not all good. I notice Jaycar state in their catalaogue that they had to change their plug-pack PSU range in order to comply with the regs.

The other issue with LEDs is that they draw little power and so may not provide enough load to start an electronic PSU.
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