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LED lighting

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A care home I frequent has installed LED lighting, I will be able to monitor the reliability.

The problem I have found with (admittedly cheap) LED spot bulbs is the difference in beam spread from a conventional spot bulb.
 
Black Hole said:
A care home I frequent has installed LED lighting, I will be able to monitor the reliability.

The problem I have found with (admittedly cheap) LED spot bulbs is the difference in beam spread from a conventional spot bulb.
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The GU10s I mentioned are 120 degree, which suits our kitchen. I wanted general illumination rather than concentrated, and I can angle them so that hardly any light is wasted going out of the window.

There are plenty of narrow beam ones available too. We have a couple as reading lights over our bed, E14 R50s.
 
I don't particularly like spot lights in the kitchen as they seem to create pools of light and dark.
I spent £3.29 at Screwfix to replace the 5' fluorescent tube (58W), which showed up how tired the old one was before it started flicking on/off.
LED is not always the answer.
 
I see LEDs are at last taking on the big boys as well with this (50Watt version) pushing out 4500 lm (Link HERE) it contains a 50 X 1 Watt LED 'chip' like this (Link HERE), I have sent for some of the 'chips' to have a play, BTW you really will need real LED drivers if you want them to last for more than a few minutes, also keep them cool
 
prpr said:
I spent £3.29 at Screwfix to replace the 5' fluorescent tube (58W), which showed up how tired the old one was before it started flicking on/off.
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They aren't the prettiest lights to use, though, are they? :disagree:

We had one in our kitchen. Half the light it emitted exited via the window. We could have fitted blinds, but we had those before the window was replaced and they were not too successful: wide, hard to reach and expensive. (It's a wide window!)

So, we bought a five unit bar and I stuck LEDs into it. That halved the wattage vs the tube but also halved the brightness. The new bulbs are still 5w LEDs but bring the light back to where it was, without the inconvenience of frequent tube changing and tube dimming, starter failures, etc.

So, hopefully, if these last, they will pay their way. Although, how you measure that I don't really know:

- Higher initial cost
- Lower running cost
- No need for blinds on the window
- No frequent tube changes/flickering
- Looks far superior
- No uneven lighting
- Light at full intensity immediately
- Easy to fit


LED was the answer in our case, on most points.
 
A recent Which? report. I had a Philips one fail within months myself. Philips took months more to replace it. Fortunately, it had failed well within its claimed lifetime even if it had been on 24/7.
6,000 hours is far less than the bulbs currently claim.

Many LED light bulbs stop working before the end of their promised life span, and some – including bulbs from Ikea and TCP – didn’t even reach the EU’s soon-to-be implemented minimum lifespan of 6,000 hours, new Which? research has discovered.
From 1 March, new EU regulations say that 90% of any batch of LED bulbs should last at least 6,000 hours.
Five types of bulb stopped working before the 6,000-hour mark for the majority of samples we tested. The TCP and Ikea bulbs were the only ones sold in the UK – both have now been discontinued.
We test light bulbs more thoroughly than anyone else. Check out our light bulb reviews to discover which bulbs are worth buying and which ones you should avoid.
How we test LED light bulb life span

In the tests – carried out by Which? and our European partner organisations – we took five samples each of 46 different bulbs. The bulbs were switched on for 165 minutes, then off for 15 minutes, in a continuous cycle until they died.
We tested 230 bulbs in total, and 66 of those failed before the 10,000 hour mark, despite all of them claiming a lifespan of at least 15,000 hours.
LED light bulb manufacturers respond

Ikea said the bulb had passed its own tests and those in a third-party lab. It is looking into why the bulb failed our test and has removed it from sale in countries where it was still available.
TCP said it was already aware of the problem with this bulb, which is why it withdrew it from sale. TCP added that it no longer deals with the supplier of that bulb and now makes its LED bulbs in-house.
We’re in the process of testing the life span of many more LED bulbs – we’ll update you if we find others that burn out prematurely.
If you’ve bought bulbs that haven’t lasted as long as they should, let us know at our Which? Conversation post on LED light bulbs.
 
Why me?

Yes, LED emitters do produce a lot of heat as well as light, but are more efficient than other forms of lighting (except maybe bioluminescence). I swapped a normal festoon bulb illuminating my car number plate for a LED equivalent, and the fitting still gets hot but not as hot as it used to. And that's only a 5W equivalent!

The problem is that LEDs produce the light and heat from a very small area, and although the light radiates away perfectly well (the whole point!) it requires a substantial heat conduction path to keep the device within acceptable limits without active cooling (heat pipes, fans, liquid cooling). It is this aspect which is holding back the general introduction of LED illumination.

Filament lamps can sustain temperatures of a couple of thousand degrees no problem; semiconductor junctions can't, and the higher the temperature they run at the shorter their life.
 
So do you recommend buying LED bulbs that have a large heat sink?
 
I wouldn't recommend LED lighting in an domestic incandescent form factor at all, at least not at the current state of the art. Industrial applications and specifically-designed LED light fittings can take the heat dissipation into account, trying to fit 60W-equivalent of LED power into a package the size of a standard 240V bulb is still a bit marginal.
 
The LED lights detailed in #25 consume roughly a tenth of the power of an incandescent lamp for the same brightness (Lumen output) so you can expect the LED equivalent of a 500Watt security light to draw only 50Watts, however as stated above LEDs need to run a lot cooler than incandescent lamps (about 80Deg C Max). External security lights are usually one big chunk of aluminium and are not run at ambient room temperature, so dissipating the heat is not a big problem. A LED version of the old 60Watt bulb is less efficient than the bigger units drawing say 8 / 9Watts and is obviously run in ambient room temperature, so keeping the LEDs below 80Deg C in a light bulb sized unit is more difficult and is probably why LED equivalents of the standard 100Watt bulb are not common. Bulbs with a visible external heat sink tend to look a bit ugly and are commonly a bit bigger than the old light bulb, but it's worth remembering that as they run a lot cooler they can be placed in closer proximity to things that need to be kept away from heat, e.g lamp shades. The manufacturer should design the unit to run at a temperature that does not shorten it's life and I think on the whole that they do, with possible exception of some 'no-name' Chinese imports
 
Black Hole said:
I wouldn't recommend LED lighting in an domestic incandescent form factor at all, at least not at the current state of the art. Industrial applications and specifically-designed LED light fittings can take the heat dissipation into account, trying to fit 60W-equivalent of LED power into a package the size of a standard 240V bulb is still a bit marginal.
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I have some fantastic LED spots in my kitchen. 6W replacing the old 60W R63s with no visible difference (I know because I replaced two of them without telling my wife and the only thing she noticed was that they take a split second longer to go out when you flick the switch).
I also have 1200 lumen LED bulbs in other rooms as the sole source of light. Slightly larger than the 100W incandescents they replaced but good light and instant too.
 
The 6W replacement for your 60W R63s is probably a bit dimmer as it's only pushing out 390 Lumens whereas the old 60Watt is nearer 800 Lumens, but colour and beam angle also need to be taken into consideration

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Side by side with one of the old R63s, I can't tell the difference though, which is what matters. I think the technology is getting there (as long as you don't buy a bulb which is already a couple of generations old from a supermarket or DIY place!)
 
True - but the old halogen R63s I was using blew quite often even though I'm not aware of any inherent instability in the mains supply. I'll let you know : )
 
Another surprising benefit of the LED R63s is that if your household mains supply drops to just under 80V for a few hours in a morning following strong winds overnight, they still work fine!
It's surprising how many devices don't seem to mind although I think the kettle would have taken a fair while to boil.
 
Just to open another angle on tne LED debate, can they be trusted to be safe? Specsavers in Coventry city centre burnt down the other week - fire brigade confirmed it was started by a faulty LED display light.
 
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