Who makes the best LED bulbs?

[Psyclist]

I'm looking to kit our kitchen out with LED GU10s but I just don't like the apparently unavoidable blue hue from them.

I know all LEDs start off as blue and they adjust them accordingly to the colour required, but it just makes the room look like it's lit by a cheap torch and drains the colour out of everything.

The ones I've got in right now are DeltechUK ones and frankly they're bloody awful.

I can't help but think if the industry is trying to push everyone towards LEDs and away from incandescent or even beyond CFLs, they're going to have to try a lot harder with the development of LEDs and their price.

I appreciate they last a lot longer but from what I've seen so far, the light from them isn't nice at all.

 

[EFLImpudence]

...away from incandescent

They've already done that for whatever spurious reason.

 

[sparkticus]

I know all LEDs start off as blue and they adjust them accordingly to the colour required, but it just makes the room look like it's lit by a cheap torch and drains the colour out of everything.

The light from LEDs is somewhat monochromatic, at least it does not emit the broad range of wavelengths of an incandescent lamp but that is why they are more efficient, they are not producing more IR(thermal energy) than useful light which is what most incandescent lamps do.

I can't help but think if the industry is trying to push everyone towards LEDs and away from incandescent or even beyond CFLs, they're going to have to try a lot harder with the development of LEDs and their price.

Well you should think that because that is well underway!! Though CFLs will be around for a long time. LEDs and controls for them are being aggressively developed.

I appreciate they last a lot longer but from what I've seen so far, the light from them isn't nice at all.

That will improve. There are three major developments in the pipeline for LEDs (in the context of general illumination of rooms etc)

1) Improved bandwidth (a broader range of wavelengths from a single LED) This is a function of the substrate and the doping materials.
2) Improved dimming in the form of LEDs mounted on microelectronic dimming substrates.
3) Improved light output (this is mostly a function of quantum efficiency to create more light and engineered nano-structures to allow more light to escape.

Currently LED dimming is a challenge but Texas Instruments, Philips and others are developing the technology because there is a large market potential!

At the moment if you want a good LED lamp that can be dimmed then I would go with Philips and expect to pay upwards of £26/lamp.

 

[Psyclist]

Well I know and although I can understand it from a consumption point of view, I really do think they should have waited until we have the technology to accurately replicate the light given from incandescent bulbs which we just don't.

Where I work is a perfect example. I work in a country house hotel and we have a lot of chandeliers around the hotel, and they look awful with CFL candle bulbs and the light just gets absorbed into the wooden panelling on the walls.

I've got enough 60W candles left to keep the main chandelier in reception going for the next few months just to keep it looking nice and then I'll just move onto halogen bulbs instead, but they're not much of a saving in terms of energy and as with the GU10 bulbs, they don't seem to last 2 mins.

 

[westie101]

They are coming available, most tungsten bulbs are in the range of around 3500K. Careful shopping can now find LEDs in the same range rather than the 6000K that is more common!

e.g. at a stated 2700K
http://www.wickes.co.uk/philips-3w-gu10-led-spot-bulb/invt/218939/?source=123_4

 

[sparkticus]

Well I know and although I can understand it from a consumption point of view, I really do think they should have waited until we have the technology to accurately replicate the light given from incandescent bulbs which we just don't.

I don't disagree in principle but industry needs to fund itself then fold back some of the profit into R&D. In the collaborative development world of semiconductors one company can not develop all the technology or invest in all of the R&D (which costs billions of $s) If there were no plan to phase out incandescent lamps then industry would have little incentive to develop a replacement for it.
LED development is very expensive and is a step-by-step process. Development relies on advanced knowledge of quantum physics, chemistry, chemical engineering, leading edge photo-lithography and leading edge solid state & device physics. Tooling and re-tooling in the semiconductor world is a huge cost and there are many failures, the cost of which to absorb.

Where I work is a perfect example. I work in a country house hotel and we have a lot of chandeliers around the hotel, and they look awful with CFL candle bulbs and the light just gets absorbed into the wooden panelling on the walls.

Oh I could not agree more. The incandescent lamp was indeed incandescent and provided a warm welcoming glow. But two things:
1) LED and CFLs will improve, especially LED and we will not be having this conversation in 3 years (that is my prediction)
2) You really need to shop around for LED lamps. They are far from being all equal. Philips (at the moment) are, in my opinion, the best. You might also have a chat with a good lighting designer in an effort to choose the best colour temperature to match the surroundings.

I've got enough 60W candles left to keep the main chandelier in reception going for the next few months just to keep it looking nice and then I'll just move onto halogen bulbs instead, but they're not much of a saving in terms of energy and as with the GU10 bulbs, they don't seem to last 2 mins.

Well, halogen lamps (though they have a filament like incandescent's) also rely on a "halogen cycle" a chemical process to keep the filament at it's peak. That is a delicate process and if they are dimmed in any way then that process in undermined and they have a short life.

 

[EFLImpudence]

If there were no plan to phase out incandescent lamps then industry would have little incentive to develop a replacement for it.

If there were no plan to phase out incandescent lamps then industry would have little reason to develop a replacement for it.

 

[Psyclist]

None of them are dimmed like, however if the rest of the hotel is anything to go by, the actual light fittings won't be the best quality. Look nice, but sh1te in reality.

Same goes for the kitchen really. No dimming, but the light fittings were reasonably low price. I bought a couple of "decent" LED bulbs from one of my sales reps the other day but I forgot to check the dimensions and the new LED GU10s are about 5mm longer than the normal ones so I can't get the locking ring back in to hold the bulb in place.

Just to go with what you're saying. The Deltech bulbs are about 12 months old whereas the ones I just bought were supplied to my merchant about a fortnight ago and the light is noticeably better from 3 LEDs compared to 21 in the old ones.

I totally understand about the R&D thing and I see what you're saying about the motivation to develop technology if the old materials are prohibited, but there are some cases where energy saving simply isn't an option. CFLs don't last two seconds in our sauna and in the lights above the cooking ranges in the restaurant kitchens where I would normally use Rough Service bulbs, but I can't get them now and I'm back to using CFLs which last about a week or two at the most in those kind of temperatures.

 

[sparkticus]

If there were no plan to phase out incandescent lamps then industry would have little incentive to develop a replacement for it.

If there were no plan to phase out incandescent lamps then industry would have little reason to develop a replacement for it.

HaHa, well I can't argue with that

In fact I do not "blindly" support what has been done/the way it has been done and I miss the incandescent and indeed the thermionic valve!! but having worked (in the distant past) in the opto-electronics world then I think I can see a point (not too far from now) where the semiconductor (LED) equivalent will provide the same "warmth" without providing the heat if you see what I mean (though they will also cost more upfront I think)

 

[JohnW2]

Currently LED dimming is a challenge ....

That comes as a surprise to me. 'On the bench' an LED would seem (to me) to win hands down over both incandescents and fluorescents (ands virtually any other lighting technology) in terms of the ability to vary light output without substantial loss of efficiency, change in colour temperature, undesired effects (e.g.'flickering') or effect on lamp life. Do I take it that the 'challenge' relates to controlling the dimming via 'mains wiring', rather than the dimming process itself?

Kind Regards,John.

 

[sparkticus]

None of them are dimmed like, however if the rest of the hotel is anything to go by, the actual light fittings won't be the best quality. Look nice, but sh1te in reality.

Are they in a position where they vibrate are subject to vibration? I mean from the surroundings? Are they mounted facing down, up or sideways?
They may not be intentionally dimmed but are they suffering from under-volts? In other words, is there a significant voltage drop on that circuit?

Same goes for the kitchen really. No dimming, but the light fittings were reasonably low price. I bought a couple of "decent" LED bulbs from one of my sales reps the other day but I forgot to check the dimensions and the new LED GU10s are about 5mm longer than the normal ones so I can't get the locking ring back in to hold the bulb in place.

Yes, and the dimmable ones are even longer.

Just to go with what you're saying. The Deltech bulbs are about 12 months old whereas the ones I just bought were supplied to my merchant about a fortnight ago and the light is noticeably better from 3 LEDs compared to 21 in the old ones.

Yes you will see rapid developments/improvements over the next two/three years.

I totally understand about the R&D thing and I see what you're saying about the motivation to develop technology if the old materials are prohibited, but there are some cases where energy saving simply isn't an option. CFLs don't last two seconds in our sauna and in the lights above the cooking ranges in the restaurant kitchens where I would normally use Rough Service bulbs, but I can't get them now and I'm back to using CFLs which last about a week or two at the most in those kind of temperatures.

Ah yes, direct heat is a problem and would also be a problem for LEDs. Taking them out and replacing with cold cathode strips might be a better option.

 

[sparkticus]

Currently LED dimming is a challenge ....

Do I take it that the 'challenge' relates to controlling the dimming via 'mains wiring', rather than the dimming process itself?

Yes, the main challenge is in the "retrofit world" making the likes of halogen downlight lamp LED replacement difficult due to restricted space and making it work with existing TRIAC based dimmers. There is also the challenge of harmonic PF correction including EMC compliance which needs to be incorporated in the lamp. Most LED dimmer chips (the ones actually in the lamp itself) use PWM modulators which appear troublesome at low levels because they become unstable/generate harmonics when operated at fractional phase angles (the TRIAC phase control)

From what I see, the general approach (at least from Philips and TI) is to incorporate DSP technology into the lamp to compensate for all ills.

Of course (and as you suggest) if you have the luxury of replacing everything and more space then dimming an LED is quite easy and not troublesome at all.
Many such systems use the industry standard 0-10 volt system which in turn alters the PWM parameters.

Here is some general info http://apps1.eere.energy.gov/buildings/publications/pdfs/ssl/dimming_leds.pdf

I also have a Texas Instruments link but it is currently password protected. it is very informative and I will try to publish it.