LED Lighting

Discussion in 'Designing, building, making and powering your life' started by zzsstt, Mar 13, 2009.

  1. zzsstt

    zzsstt Junior Member

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    I'm in the process of building a new house, and currently investigating lighting. The majority of the lighting will be by (T5) fluoro's, but I'm struggling with the rest (mainly task lighting or frequqntly switched lighting like staircases).

    Given:

    GLS are out, soon to be banned anyway.

    CFL's I have found do not last anywhere near their claimed times, look ugly, contain mercury, take 15 minutes to warm up, rapidly reduce their light output and fail very quickly if used in the most efficient manner (i.e. switched on/off when required).

    GU10 240V halogens produce less light per watt than 12V halogens, even allowing for transformer loss, with a 2000hr life expectancy (claimed).

    GU10 CFL spotlights are utterly useless in every way.


    My research has shown that MR16 12V halogens with an electronic power supply, in the "IR" 35watt version, produce good amounts of light (the same as a normal 50W MR16, 30% less energy consumed), with good life expectancy (5000hrs claimed), no warm-up time and apparently no great aversion to frequent switching (within reason). About $14 each.

    I have no experience of LEDs but as far as I can establish, to produce the same light output as a 50W MR16 requires about 11W of LED lighting. However the largest MR16 "LED" I can find is 6.5W, and costs $100. Granted it has a claimed 50,000hr life expectancy, but they do not quote a guarantee period (I have emailed, no response as yet). Additionally I note the "life expectancy" (like CFLs) is not time to failure, but time to 50% reduction in output, meaning that for task lighting the actual useful life may be far less. I also note that all these numbers are based on calculations. Like CFL's, the actual life may turn out to be far less than the "extrapolated" suggestion. BTW I do not know the decay rate of the MR16's output.

    So as far as I can see, I can spend $14 on a 35W MR16 or $200 on a pair of 6.5W LED's to get the same light output. If both units run their full life expectancy, I need to buy 10 12V halogens (5000hrs each) for $140, or two (possibly three to allow for output decay) LEDs, for $200 (or $300!).

    At 14c/kWhr, the LEDs will use $91 whilst the 35W MR16s will use $245 in the 50,000 hour. If I allow an additional LED to make up for reduce output from 50% of the life expectancy, the $91 rises to $136.

    So:
    MR16 12V for 50,000 hours costs $385
    LED for 50,000 hours costs at least $291, possibly up to $436 (3 LEDs from 50% life expectancy to maintain usable output)

    With the 12Vs I have complete confidence in the system, it is tried and tested. If a better alternative comes along I have minimal investment and can adopt the new technology at any point.

    With LEDs I am locking myself in to a new untested system, which at best is only 25% cheaper but could in fact easily cost me more, and in which I have a massive up front investment. If the claimed life expectancy does not eventuate, and it's only an extrapolation, it has cost more money. If a better option is released in 5 years time, I have too great an investment to abandon.

    So my current thinking is that LED's may be fun as expensive toys and rope lights, but full sized fluoros and 35W MR16's (turned off when not required) are the best real world solution.

    Have I missed anything, or does anyone have a better solution?
     
  2. dgriffith

    dgriffith Junior Member

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    Re: LED Lighting

    I generally agree - LED lighting isn't there yet.
    Perhaps for task lighting, one can get away with it - a reading light over a chair, for example.

    Regarding CFL's - have you tried the Philips 'Tornado' ones? I run the 5W/10W ones exclusively in my off-grid setup - instant on, pretty good lumens/watt, good spread (which LED's pretty much fail at), a variety of colour temps to pick from. No apparent loss in lumens for me so far, *but* they do take 20 or 30 seconds to warm up to full brightness when it's cold (read: 10 degrees C) - it's not a 'pathetic glow' to 'full brightness' warm up, but it is noticable. They're compact enough fit directly into most light fittings. And for $6 each.....well, beats LEDs for price.

    Some of the cold cathode compact fluoros (the megaman ones in particular) are interesting, but I haven't had a good look at them yet.
     
  3. zzsstt

    zzsstt Junior Member

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    Re: LED Lighting

    When I first replaced my lights with CFL's, the Philips branded units were the only ones to last more than a few months. As a result, they are now the only brand I'd consider buying. However I haven't bought any for a while, nor tried the Tornado model.

    How long have you had your Tornado's? Are they used in a "frequent switching" environment? For the places where a light will be on for a long time (lounge, general kitchen lighting etc.) I have settled on circular T5's as the best option. I'm struggling with task lighting for short term use, like kitchen benchtops whilst cooking, and intermittent use like staircase lights which are switched on only for the time it takes to traverse the stairs. I found the old Philips unit gave best performance and longevity when used to provide general lighting, and were much less useful for task lighting (could be a luminaire issue, perhaps they are better now!) and hopeless for on/off use - which is, to be fair, what it said on the packet!

    I'll give the Tornados a test if I can find one!
     
  4. drrdave27

    drrdave27 Junior Member

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    Re: LED Lighting

    Hi all

    Im an electrician and we install a fair bit of lighting, this is my opinion only, but you cant go past the compact fluro. LED's are good like dgriffith said for close up mood or decroative lighting. Although please note that even though all fluroscent lamps claim to have a life of xxxxx hrs, they will loose up to 60% of their light output over this time. I would stay away from 12V halogen downlights as they burn down a house a week in Brisbane, very hot and dangerous if not installed properly. Also there are ways to safley recycle old fluro lamps, we go throught about 50 of the 4ft tubes a week and they get picked up by Wanless at work and recycled.

    Just make sure you get good quality fittings as the cheap stuff = fire hazard.

    hope this helps :rolleyes:
     
  5. zzsstt

    zzsstt Junior Member

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    Re: LED Lighting

    I received a reply about the LED guarantees. Basically the very expensive larger LED's ($100+) have a two year warranty, the others all have one year. Pretty much what I expected, to be honest, and another nail in the coffin for LED's!

    12V halogens do generate heat, though less than a GLS. The IRC versions generate less again, both from higher efficiency (more light, less heat) and also because they are a lower power device (35W vs 50W). I also don't intend to use them in recessed fittings, so there should be no problems with them starting fires...hopefully!

    I am still not keen on CFL's for frequent switched applications, and I have yet to see one that produces good task lighting - obviously I could use several but then the power saving would be gone! The GU10 CFLs (I bought 3 to try) are a complete waste of time.

    By the way, I keep reading about how bad it is to have all these devices that produce heat not light (aka "inefficient") but it occurs to me that for upwards of a third of the year I have to heat my house for at least some of the day. Through the summer, when the daylight hours are longer, I do not use the lights as much as in the winter. Surely this means that, at least to some extent, my overall energy savings are reduced because in winter the heat normally produced by the "inefficient" lights will now need to be produced by some other means? And in summer the savings are less because I don't switch the lights on.......

    Like "water saving taps", I am starting to suspect that the only real way to save energy (or water) is to simply switch 'em off when they're not in use!
     
  6. dgriffith

    dgriffith Junior Member

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    Re: LED Lighting

    Everything is frequently switched here, my solar input doesn't keep up with usage :lol:
    Installed Tornados in here when I moved in 12 months ago, so every light fitting in the house is now CFL. Have run them nightly from mod-sine inverters, wobbly generator power and now a sinewave inverter, haven't burnt one out yet.


    If you've got cupboards above the bench, those Megaman GX53 ones might be of interest. A 'proper' lighting shop should have them. Like this mob : https://www.beaconshop.com.au
    Or neco : https://www.neco.com.au

    You can probably get away with MR16 lights for the stairs. The amount of time that they're on during the year isn't an issue. Put a pushbutton timer in though. Possibly you could get 3 or 4 1W MR16 LED's in at knee height pointing down at the tread for something different. This gives adequate illumination near your feet where you need it for low power. It also doesn't wreck your night vision as much if you have to go downstairs at night :D

    Woolworths sell them....
     

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