Nearly 3 years ago I bought several 13W LED bulbs from Messrs Ryness lighting in Old Compton St in London. They were expensive, £11-99 each, but I was reassured to see that they had a 3 year guarantee.

Last week one of the 3 started flickering: not a great loss of light output, but very distracting to anyone using it and probably a sign that it was about to fail. I had, being so doubtful about LEDs, kept the receipt and dug it out to find it was only 2 years 11 months and three weeks since purchase. So I took it back and I managed to persuade the manager of Ryness to replace it. Even more amazingly, the price of these has now gone up from nearly £12 to £18. Maybe that's because so many have failed and had to be replaced. I have to assume that the claimed lifetime of 50,000 hours (a decade or two at our typical usage) is just a wild extrapolation from their testing programme and wouldn't rely on that at all.


--
Clive Page

There is a world of difference between the actual light emitting bits life
and the life orf a unit containing many leds and circuitry to run them of
course over time. Lots more to go wrong like poor connections and local
overheating and of course the dreaded mains spike!
Brian

--
----- -
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please!
"Clive Page" wrote in message
...
Nearly 3 years ago I bought several 13W LED bulbs from Messrs Ryness
lighting in Old Compton St in London. They were expensive, £11-99 each,
but I was reassured to see that they had a 3 year guarantee.

Last week one of the 3 started flickering: not a great loss of light
output, but very distracting to anyone using it and probably a sign that
it was about to fail. I had, being so doubtful about LEDs, kept the
receipt and dug it out to find it was only 2 years 11 months and three
weeks since purchase. So I took it back and I managed to persuade the
manager of Ryness to replace it. Even more amazingly, the price of these
has now gone up from nearly £12 to £18. Maybe that's because so many have
failed and had to be replaced. I have to assume that the claimed
lifetime of 50,000 hours (a decade or two at our typical usage) is just a
wild extrapolation from their testing programme and wouldn't rely on that
at all.


--
Clive Page

On 15/11/2017 12:18, Clive Page wrote:
Nearly 3 years ago I bought several 13W LED bulbs from Messrs Ryness
lighting in Old Compton St in London.Â* They were expensive, £11-99 each,
but I was reassured to see that they had a 3 year guarantee.

Last week one of the 3 started flickering: not a great loss of light
output, but very distracting to anyone using it and probably a sign that
it was about to fail.Â* I had, being so doubtful about LEDs, kept the
receipt and dug it out to find it was only 2 years 11 months and three
weeks since purchase.Â*Â* So I took it back and I managed to persuade the
manager of Ryness to replace it.Â* Even more amazingly, the price of
these has now gone up from nearly £12 to £18.Â* Maybe that's because so
many have failed and had to be replaced.Â*Â* I have to assume that the
claimed lifetime of 50,000 hours (a decade or two at our typical usage)
is just a wild extrapolation from their testing programme and wouldn't
rely on that at all.



I'm unconvinced re LED lights in the domestic setting, not so much due
to the life (although it is good to see a seller honouring his warranty)
but more the light output. We have them in our motorhome and, in the
confined space, they are OK. However, we tried them in the kitchen
(replacing some halogen bulbs - 2x40W halogen per fitting) and with LEDs
they were hopeless. I forget the rating of the LEDs but they were,
supposedly, equivalent to 40W bulbs. At a guess, they were more like 25W.



--

Suspect someone is claiming a benefit under false pretences? Incapacity
Benefit or Personal Independence Payment when they don't need it? They
are depriving those in real need!

https://www.gov.uk/report-benefit-fraud

On 15/11/2017 13:48, Brian Reay wrote:
On 15/11/2017 12:18, Clive Page wrote:

Nearly 3 years ago I bought several 13W LED bulbs from Messrs Ryness
lighting in Old Compton St in London.Â* They were expensive, £11-99
each, but I was reassured to see that they had a 3 year guarantee.

Last week one of the 3 started flickering: not a great loss of light
output, but very distracting to anyone using it and probably a sign
that it was about to fail.Â* I had, being so doubtful about LEDs, kept
the receipt and dug it out to find it was only 2 years 11 months and
three weeks since purchase.Â*Â* So I took it back and I managed to
persuade the manager of Ryness to replace it.Â* Even more amazingly,
the price of these has now gone up from nearly £12 to £18.Â* Maybe
that's because so many have failed and had to be replaced.Â*Â* I have to
assume that the claimed lifetime of 50,000 hours (a decade or two at
our typical usage) is just a wild extrapolation from their testing
programme and wouldn't rely on that at all.

Their demise can also be hastened by putting them in unsuitable fixtures
where heat builds up sufficiently to dry out the PSU capacitors. The
sealed glass globe type are particularly bad for them.

I'm unconvinced re LED lights in the domestic setting, not so much due
to the life (although it is good to see a seller honouring his warranty)
but more the light output.Â* We have them in our motorhome and, in the
confined space, they are OK. However, we tried them in the kitchen
(replacing some halogen bulbs - 2x40W halogen per fitting) and with LEDs
they were hopeless. I forget the rating of the LEDs but they were,
supposedly, equivalent to 40W bulbs. At a guess, they were more like 25W.

Odd. I would agree where CFL are concerned that equivalent light output
was vastly overstated, but all the LED bulbs I have ever bought have
produced something approximating their claimed equivalent brightness.
The first one I bought a nominal 60W equivalent was far too bright in a
small bathroom (the "60W" CFL was about right but failing due to age). A
40W equivalent LED bulb did the trick.

--
Regards,
Martin Brown

"Brian Reay" wrote in message
news
On 15/11/2017 12:18, Clive Page wrote:
Nearly 3 years ago I bought several 13W LED bulbs from Messrs Ryness
lighting in Old Compton St in London. They were expensive, £11-99 each,
but I was reassured to see that they had a 3 year guarantee.

Last week one of the 3 started flickering: not a great loss of light
output, but very distracting to anyone using it and probably a sign that
it was about to fail. I had, being so doubtful about LEDs, kept the
receipt and dug it out to find it was only 2 years 11 months and three
weeks since purchase. So I took it back and I managed to persuade the
manager of Ryness to replace it. Even more amazingly, the price of these
has now gone up from nearly £12 to £18. Maybe that's because so many
have failed and had to be replaced. I have to assume that the claimed
lifetime of 50,000 hours (a decade or two at our typical usage) is just a
wild extrapolation from their testing programme and wouldn't rely on that
at all.



I'm unconvinced re LED lights in the domestic setting, not so much due to
the life (although it is good to see a seller honouring his warranty) but
more the light output. We have them in our motorhome and, in the confined
space, they are OK. However, we tried them in the kitchen (replacing some
halogen bulbs - 2x40W halogen per fitting) and with LEDs they were
hopeless. I forget the rating of the LEDs but they were, supposedly,
equivalent to 40W bulbs. At a guess, they were more like 25W.

I've got a 5W one in my room lamp

it's a damned sight brighter than the 12W CFL it replaced (and comes on
instantly)

tim

In article ,
Clive Page wrote:
Maybe that's because so many have failed and had to be replaced. I
have to assume that the claimed lifetime of 50,000 hours (a decade or
two at our typical usage) is just a wild extrapolation from their
testing programme and wouldn't rely on that at all.

These wild claims for life would be more believable if they were backed up
by a suitable warrenty. 50,000 hours would be approx 20 years at 6 hours
use per day.

--
*If they arrest the Energizer Bunny, would they charge it with battery? *

Dave Plowman London SW
To e-mail, change noise into sound.

On Wednesday, 15 November 2017 12:18:04 UTC, Clive Page wrote:
Nearly 3 years ago I bought several 13W LED bulbs from Messrs Ryness lighting in Old Compton St in London. They were expensive, £11-99 each, but I was reassured to see that they had a 3 year guarantee.

Last week one of the 3 started flickering: not a great loss of light output, but very distracting to anyone using it and probably a sign that it was about to fail. I had, being so doubtful about LEDs, kept the receipt and dug it out to find it was only 2 years 11 months and three weeks since purchase. So I took it back and I managed to persuade the manager of Ryness to replace it. Even more amazingly, the price of these has now gone up from nearly £12 to £18. Maybe that's because so many have failed and had to be replaced. I have to assume that the claimed lifetime of 50,000 hours (a decade or two at our typical usage) is just a wild extrapolation from their testing programme and wouldn't rely on that at all.


--
Clive Page

You need to lok more closely at the warrenty, most state up to 50,000 hours but only if the light isn't left on for more than 2 or 3 hours a day or at one time.
Because the biggest destroyers of LEDs isn't time but temerature.

Dave Plowman (News) pretended :
These wild claims for life would be more believable if they were backed up
by a suitable warrenty. 50,000 hours would be approx 20 years at 6 hours
use per day.

The claims are a bit wild, but even if genuine life hours were claimed
it would only be and average life - som would fall far short, some much
longer.

I have had not a single failure so far and I am pleased with the light
and the energy saving. All were cheap ones, or bought on the cheap -
direct from China or during the BHS sell off, where I bought 20x Osram
3.5w O BC LED's for general lighting purposes.

On Wednesday, November 15, 2017 at 1:48:09 PM UTC, Brian Reay wrote:
On 15/11/2017 12:18, Clive Page wrote:
Nearly 3 years ago I bought several 13W LED bulbs from Messrs Ryness
lighting in Old Compton St in London.Â* They were expensive, £11-99 each,
but I was reassured to see that they had a 3 year guarantee.

Last week one of the 3 started flickering: not a great loss of light
output, but very distracting to anyone using it and probably a sign that
it was about to fail.Â* I had, being so doubtful about LEDs, kept the
receipt and dug it out to find it was only 2 years 11 months and three
weeks since purchase.Â*Â* So I took it back and I managed to persuade the
manager of Ryness to replace it.Â* Even more amazingly, the price of
these has now gone up from nearly £12 to £18.Â* Maybe that's because so
many have failed and had to be replaced.Â*Â* I have to assume that the
claimed lifetime of 50,000 hours (a decade or two at our typical usage)
is just a wild extrapolation from their testing programme and wouldn't
rely on that at all.



I'm unconvinced re LED lights in the domestic setting, not so much due
to the life (although it is good to see a seller honouring his warranty)
but more the light output. We have them in our motorhome and, in the
confined space, they are OK. However, we tried them in the kitchen
(replacing some halogen bulbs - 2x40W halogen per fitting) and with LEDs
they were hopeless. I forget the rating of the LEDs but they were,
supposedly, equivalent to 40W bulbs. At a guess, they were more like 25W.



--

Suspect someone is claiming a benefit under false pretences? Incapacity
Benefit or Personal Independence Payment when they don't need it? They
are depriving those in real need!

https://www.gov.uk/report-benefit-fraud

I have quite a few LEDs around and quite a few CFLs left. The CFLs are now failing through age. However the filament LEDs are failing far quicker than the LEDs.

I have had Wickes 7w GU10 CFLs in the kitchen for a long time but threw them all out recently as I just couldn't cope with the negligible light output any more. They were replaced with Wickes 5w GU10s and the light output is good, probably the same as a 35W halogen.

I had a supposedly 1200 lumen LED bulb in the bathroom from Ebay, but that went in the bin too as the light output just was not sufficient and the colour awful. Light output was maybe the same as a 25W bulb at best. It got replaced with a £2.75 1520 lumen LED bulb from Home Bargains which is great, nice colour and plenty of light.

I have quite a few 4W LED filament bulbs from B&Q. They are not bad, give off just enough light but wish they were brighter. However have had 2 fail already.

Other than that I have a few Ikea LED bulbs around which I dislike. Too dim and a nasty thin colour.

What is needed is some form of independent testing and rating so you have a better idea of what you are buying.

Philip

On 15/11/2017 15:49, wrote:

Other than that I have a few Ikea LED bulbs around which I dislike.
Too dim and a nasty thin colour.

Warm white vs cold white ?

What is needed is some form of independent testing and rating so you
have a better idea of what you are buying.

LEDs are much better than CFLs in that respect - the light they produce
is roughly as bright as it would be with a classic incandescent lamp if
you buy reasonable quality units.

Some crude designs where there are very long chains of LEDs all in
series across current limited rectified mains fail completely when the
weakest LED in the chain goes pop. I have one that went this way.

Some of the really cheap and nasty Chinese imported halogen substitute
LED bulbs have naughty voltages accessible on the front face (no plastic
in front of the LEDs). You would need a pin or a probe to touch them.

--
Regards,
Martin Brown

In article ,
tim... wrote:
I've got a 5W one in my room lamp

it's a damned sight brighter than the 12W CFL it replaced (and comes on
instantly)

Yup - a rotten apple is much better than a rotten orange. ;-)

--
*I don't suffer from insanity, I enjoy every minute of it *

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
Harry Bloomfield wrote:
These wild claims for life would be more believable if they were
backed up by a suitable warrenty. 50,000 hours would be approx 20
years at 6 hours use per day.

The claims are a bit wild, but even if genuine life hours were claimed
it would only be and average life - som would fall far short, some much
longer.

Tungsten were usually pretty consistent. Similar ones in the same room
failing very close to the others.

I've had a few LEDs fail very early. Indeed 100% failure rate. The few I
have now not old enough to come to a conclusion.

I have had not a single failure so far and I am pleased with the light
and the energy saving. All were cheap ones, or bought on the cheap -
direct from China or during the BHS sell off, where I bought 20x Osram
3.5w O BC LED's for general lighting purposes.

--
*Never miss a good chance to shut up *

Dave Plowman London SW
To e-mail, change noise into sound.

On 15/11/2017 13:48, Brian Reay wrote:


I'm unconvinced re LED lights in the domestic setting, not so much due
to the life (although it is good to see a seller honouring his warranty)
but more the light output.Â* We have them in our motorhome and, in the
confined space, they are OK. However, we tried them in the kitchen
(replacing some halogen bulbs - 2x40W halogen per fitting) and with LEDs
they were hopeless. I forget the rating of the LEDs but they were,
supposedly, equivalent to 40W bulbs. At a guess, they were more like 25W.


But if you had fitted a single 40W flat panel LED I'll bet you would
have more than enough light. Its not just the LEDs but the fittings
that are important.



--
mailto: news {at} admac {dot] myzen {dot} co {dot} uk

"Brian Reay" wrote in message
news
On 15/11/2017 12:18, Clive Page wrote:
Nearly 3 years ago I bought several 13W LED bulbs from Messrs Ryness
lighting in Old Compton St in London. They were expensive, £11-99 each,
but I was reassured to see that they had a 3 year guarantee.

Last week one of the 3 started flickering: not a great loss of light
output, but very distracting to anyone using it and probably a sign that
it was about to fail. I had, being so doubtful about LEDs, kept the
receipt and dug it out to find it was only 2 years 11 months and three
weeks since purchase. So I took it back and I managed to persuade the
manager of Ryness to replace it. Even more amazingly, the price of these
has now gone up from nearly £12 to £18. Maybe that's because so many
have failed and had to be replaced. I have to assume that the claimed
lifetime of 50,000 hours (a decade or two at our typical usage) is just a
wild extrapolation from their testing programme and wouldn't rely on that
at all.



I'm unconvinced re LED lights in the domestic setting, not so much due to
the life (although it is good to see a seller honouring his warranty) but
more the light output. We have them in our motorhome and, in the confined
space, they are OK. However, we tried them in the kitchen (replacing some
halogen bulbs - 2x40W halogen per fitting) and with LEDs they were
hopeless. I forget the rating of the LEDs but they were, supposedly,
equivalent to 40W bulbs. At a guess, they were more like 25W.

There are plenty of 800 lumen LEDs like the Philips Hues. Not cheap tho.

On Wed, 15 Nov 2017 13:57:50 +0000, Martin Brown wrote:

On 15/11/2017 13:48, Brian Reay wrote:
On 15/11/2017 12:18, Clive Page wrote:

Nearly 3 years ago I bought several 13W LED bulbs from Messrs Ryness
lighting in Old Compton St in London.Â* They were expensive, £11-99
each, but I was reassured to see that they had a 3 year guarantee.

====snip====

assume that the claimed lifetime of 50,000 hours (a decade or two at
our typical usage) is just a wild extrapolation from their testing
programme and wouldn't rely on that at all.

Their demise can also be hastened by putting them in unsuitable fixtures
where heat builds up sufficiently to dry out the PSU capacitors. The
sealed glass globe type are particularly bad for them.

That would certainly be true of the older, less efficient (81Lm/W) types
we've had to contend with these past 5 years or so - during the last 3
years of which we've been kept waiting for the more efficient LEDs to
land on the shop shelves any time during the 18 to 24 months the Cree
lighting spokesperson had promised that the 303Lm/W lab samples would
take to get into production. Only now are we seeing improved LED lamps
appearing with moderately improved efficiencies of 125Lm/W which falls
woefully short of Cree's laboratory achievements of... let me check... 26
March 2014, way over 3 1/2 years ago.

https://www.forbes.com/sites/peterde...will-get-even-
more-efficient-cree-passes-300-lumens-per-watt/#65748cea2611

Read it and weep (sorry for the line wrap)!


I'm unconvinced re LED lights in the domestic setting, not so much due
to the life (although it is good to see a seller honouring his
warranty) but more the light output.Â* We have them in our motorhome
and, in the confined space, they are OK. However, we tried them in the
kitchen (replacing some halogen bulbs - 2x40W halogen per fitting) and
with LEDs they were hopeless. I forget the rating of the LEDs but they
were, supposedly, equivalent to 40W bulbs. At a guess, they were more
like 25W.

Odd. I would agree where CFL are concerned that equivalent light output
was vastly overstated, but all the LED bulbs I have ever bought have
produced something approximating their claimed equivalent brightness.
The first one I bought a nominal 60W equivalent was far too bright in a
small bathroom (the "60W" CFL was about right but failing due to age). A
40W equivalent LED bulb did the trick.

You can now buy such "40W" (6W 510lm) LED GLS lamps in Poundland these
days (both LES and BC22 types)... for just a quid each (not *everything*
is priced at one pound in Poundland and Poundworld shops these days).

I suspect when Philips first marketed their SL 'Comfort' 13 and 18 watt
range of CFLs, the industry wasn't facing any regulatory need to specify
the details of the "Incandescent GLS" reference lamp they were pitting
their product's performance against.

Quite possibly they were using a long life/rough service 220v (or
perhaps, the even lower efficacy 240v UK standard) filament lamp as their
"Standard", relying upon the characteristic 120% of "Design Lumens"
output from new of the fluorescent tube light output life curve to help
mask this discrepancy between these CFLs and regular 1000 hour rated GLS
220/240 volt filament lamps.

By the time LED lamp technology started to become a viable alternative
to the CFL, Much tighter consumer protection regulations came into force
(presumably in the US of A judging by the use of the American 806lm 60W
120v 750 hour lamp standard chosen for the sale of LED lamps claiming to
have a 60W equivalency). It's for that reason alone that we in the UK
(and likewise for Europeans no doubt) have a much better experience when
upgrading old 60 and 100 watt incandescent GLS lamps (even more so when
replacing ageing CFL versions which claim the same incandescent lamp
wattage equivalence).

The real benefit of efficiency improvements in LED lamp performance lies
not so much with reduced electricity bills so much as being able to
upgrade from a 10W 810Lm LED to a 10W 1520Lm LED in a light fixture that
provides barely sufficient cooling for the 10W 810lm lamp with the
confidence that the newer brighter lamp will run just that little bit
cooler (and quite possibly realise the 25 to 30 thousand hour promises
typically made these days) since even less of that 10W input gets turned
into waste heat.

--
Johnny B Good

On 15/11/2017 13:48, Brian Reay wrote:
I'm unconvinced re LED lights in the domestic setting, not so much due to the life (although it is good to see a seller honouring his warranty) but more the light output.Â* We have them in our motorhome and, in the confined space, they are OK. However, we tried them in the kitchen (replacing some halogen bulbs - 2x40W halogen per fitting) and with LEDs they were hopeless. I forget the rating of the LEDs but they were, supposedly, equivalent to 40W bulbs. At a guess, they were more like 25W.

It must depend on the type of bulb and the context, because I've found the opposite. These 13W bulbs have a rated output of 1060 Lumens which is supposed to be equivalent to 75W of incandescent filament. But I've put them in places where there used to be 100W or even 150W incandescents and found them adequate, because, I think, they are not as omnidirectional. Since more of the light goes downwards which is where we need it, the effective brightness is rather similar.

But one thing I forgot to mention: the replacement LED I got has an almost identical box to the original except that (1) the price is 50% higher, and (2) the guarantee has gone down from 3 years to 2. Obviously I'm not the only one to have had a bulb fail after just over 2 years!

--
Clive Page

On 15/11/2017 23:36, Johnny B Good wrote:
On Wed, 15 Nov 2017 13:57:50 +0000, Martin Brown wrote:

On 15/11/2017 13:48, Brian Reay wrote:
On 15/11/2017 12:18, Clive Page wrote:

assume that the claimed lifetime of 50,000 hours (a decade or two at
our typical usage) is just a wild extrapolation from their testing
programme and wouldn't rely on that at all.

Their demise can also be hastened by putting them in unsuitable fixtures
where heat builds up sufficiently to dry out the PSU capacitors. The
sealed glass globe type are particularly bad for them.

That would certainly be true of the older, less efficient (81Lm/W) types
we've had to contend with these past 5 years or so - during the last 3
years of which we've been kept waiting for the more efficient LEDs to
land on the shop shelves any time during the 18 to 24 months the Cree
lighting spokesperson had promised that the 303Lm/W lab samples would
take to get into production. Only now are we seeing improved LED lamps
appearing with moderately improved efficiencies of 125Lm/W which falls
woefully short of Cree's laboratory achievements of... let me check... 26
March 2014, way over 3 1/2 years ago.

https://www.forbes.com/sites/peterde...will-get-even-
more-efficient-cree-passes-300-lumens-per-watt/#65748cea2611

Read it and weep (sorry for the line wrap)!

The 300Lm/W was achieved on a near infinite heatsink under perfect
laboratory conditions with a fabrication technique that doesn't easily
scale up - basically a one off research device made of unobtanium.

Around 130Lm/W is the current production device which is still
impressive and better than HPS (but still short of 220Lm/W LPS).

I'm unconvinced re LED lights in the domestic setting, not so much due
to the life (although it is good to see a seller honouring his
warranty) but more the light output.Â* We have them in our motorhome
and, in the confined space, they are OK. However, we tried them in the
kitchen (replacing some halogen bulbs - 2x40W halogen per fitting) and
with LEDs they were hopeless. I forget the rating of the LEDs but they
were, supposedly, equivalent to 40W bulbs. At a guess, they were more
like 25W.

Odd. I would agree where CFL are concerned that equivalent light output
was vastly overstated, but all the LED bulbs I have ever bought have
produced something approximating their claimed equivalent brightness.
The first one I bought a nominal 60W equivalent was far too bright in a
small bathroom (the "60W" CFL was about right but failing due to age). A
40W equivalent LED bulb did the trick.

You can now buy such "40W" (6W 510lm) LED GLS lamps in Poundland these
days (both LES and BC22 types)... for just a quid each (not *everything*
is priced at one pound in Poundland and Poundworld shops these days).

It is astonishing how the prices have fallen.

I suspect when Philips first marketed their SL 'Comfort' 13 and 18 watt
range of CFLs, the industry wasn't facing any regulatory need to specify
the details of the "Incandescent GLS" reference lamp they were pitting
their product's performance against.

Quite possibly they were using a long life/rough service 220v (or
perhaps, the even lower efficacy 240v UK standard) filament lamp as their
"Standard", relying upon the characteristic 120% of "Design Lumens"
output from new of the fluorescent tube light output life curve to help
mask this discrepancy between these CFLs and regular 1000 hour rated GLS
220/240 volt filament lamps.

I think the CFL claims were just bare faced lies on the part of the
marketing men and slimy salesmen.

By the time LED lamp technology started to become a viable alternative
to the CFL, Much tighter consumer protection regulations came into force
(presumably in the US of A judging by the use of the American 806lm 60W
120v 750 hour lamp standard chosen for the sale of LED lamps claiming to
have a 60W equivalency). It's for that reason alone that we in the UK
(and likewise for Europeans no doubt) have a much better experience when
upgrading old 60 and 100 watt incandescent GLS lamps (even more so when
replacing ageing CFL versions which claim the same incandescent lamp
wattage equivalence).

I think part of it is that there is a global standard now and US rules
based on their lower voltage incandescent filament bulbs have made LED
nominal equivalents brighter as a result. Thicker low voltage filament
can run hotter and be more efficient.

The real benefit of efficiency improvements in LED lamp performance lies
not so much with reduced electricity bills so much as being able to
upgrade from a 10W 810Lm LED to a 10W 1520Lm LED in a light fixture that
provides barely sufficient cooling for the 10W 810lm lamp with the
confidence that the newer brighter lamp will run just that little bit
cooler (and quite possibly realise the 25 to 30 thousand hour promises
typically made these days) since even less of that 10W input gets turned
into waste heat.

I think in an ideal world new LED luminaires should be designed to take
into account the strengths and weaknesses of the physical devices. This
is now happening but the change over will be slow. Some types of older
sealed glass bowl lamp shades spell a short hot life for LED bulbs.

--
Regards,
Martin Brown

On Thu, 16 Nov 2017 11:57:22 +0000, Martin Brown wrote:

The 300Lm/W was achieved on a near infinite heatsink under perfect
laboratory conditions with a fabrication technique that doesn't easily
scale up - basically a one off research device made of unobtanium.

Around 130Lm/W is the current production device which is still
impressive and better than HPS (but still short of 220Lm/W LPS).

As far as what is on the shelves you're hard pushed to get over
100lm/Watt. I quite like the newer stick filament type, in standard
sort of clear envelopes not the fancy "period" ones. You have to
watch the power and lm numbers as not all are 100lm/W. The warm
white colour temperature is good, and light dispersion very similar
to perl tungsten. They don't appear to have any electronics either.
Not had this type long enough to comment on life.

The LED failures I've had have been the chips falling off the
board/heatsink...

Also recently swapped some 5' 58W flory tubes to LED. The first was a
bit of a distress purchase and is a Philips 20 W 2000 lm that cost
around £15. Two others came from Aldi at £4.99 each (flogging 'em
off), 22W 2000 lm. Now a 58 W flory is supposed to chuck out 5000 lm
so at 2000 lm was a little concerned that the LED tubes would be
rather dim. In practice straight after swapping think, "hum it's not
quite as light". But after using them for a while I no longer notice
or think there isn't enough light.

--
Cheers
Dave.

On Thu, 16 Nov 2017 11:57:22 +0000, Martin Brown wrote:

On 15/11/2017 23:36, Johnny B Good wrote:
On Wed, 15 Nov 2017 13:57:50 +0000, Martin Brown wrote:

On 15/11/2017 13:48, Brian Reay wrote:
On 15/11/2017 12:18, Clive Page wrote:

assume that the claimed lifetime of 50,000 hours (a decade or two at
our typical usage) is just a wild extrapolation from their testing
programme and wouldn't rely on that at all.

Their demise can also be hastened by putting them in unsuitable
fixtures where heat builds up sufficiently to dry out the PSU
capacitors. The sealed glass globe type are particularly bad for them.

That would certainly be true of the older, less efficient (81Lm/W)
types
we've had to contend with these past 5 years or so - during the last 3
years of which we've been kept waiting for the more efficient LEDs to
land on the shop shelves any time during the 18 to 24 months the Cree
lighting spokesperson had promised that the 303Lm/W lab samples would
take to get into production. Only now are we seeing improved LED lamps
appearing with moderately improved efficiencies of 125Lm/W which falls
woefully short of Cree's laboratory achievements of... let me check...
26 March 2014, way over 3 1/2 years ago.

https://www.forbes.com/sites/peterde...leds-will-get-
even-
more-efficient-cree-passes-300-lumens-per-watt/#65748cea2611

Read it and weep (sorry for the line wrap)!

The 300Lm/W was achieved on a near infinite heatsink under perfect
laboratory conditions with a fabrication technique that doesn't easily
scale up - basically a one off research device made of unobtanium.

When you're diverting more of the input power into light emission and
less into waste heat, I'm not so sure of the need for "a near infinite
heatsink" even in a laboratory setup. I agree that the novel fabrication
of the lab sample is the major obstacle to mass production of a lamp that
needs *less* heatsinking due to a notable reduction of the waste energy
fraction of its input power.


Around 130Lm/W is the current production device which is still
impressive and better than HPS (but still short of 220Lm/W LPS).

Interestingly, I noticed (only after posting) that the "Breaking
Barriers" graph on that web page indicates a "Lab to Shelf" lead time
more like 10 years rather than the Cree vice president for product
strategy's quote of "18 to 24 months". If only he'd seen that graph, he
could have saved his embarrassment.

In case you missed it, the graph started with a 'landmark break through'
of 131 LPW way back in 2006. At that rate, don't expect to see 160LPW
lamps for another two years at least.


I'm unconvinced re LED lights in the domestic setting, not so much
due to the life (although it is good to see a seller honouring his
warranty) but more the light output.Â* We have them in our motorhome
and, in the confined space, they are OK. However, we tried them in
the kitchen (replacing some halogen bulbs - 2x40W halogen per
fitting) and with LEDs they were hopeless. I forget the rating of the
LEDs but they were, supposedly, equivalent to 40W bulbs. At a guess,
they were more like 25W.

Odd. I would agree where CFL are concerned that equivalent light
output was vastly overstated, but all the LED bulbs I have ever bought
have produced something approximating their claimed equivalent
brightness. The first one I bought a nominal 60W equivalent was far
too bright in a small bathroom (the "60W" CFL was about right but
failing due to age). A 40W equivalent LED bulb did the trick.

You can now buy such "40W" (6W 510lm) LED GLS lamps in Poundland
these
days (both LES and BC22 types)... for just a quid each (not
*everything* is priced at one pound in Poundland and Poundworld shops
these days).

It is astonishing how the prices have fallen.

Its 470lm predecessor (also a 6W lamp) had an efficiency of 78 LPW versus
this latest 510lm 6W version's 85 LPW efficiency. BTW, the power
consumption of this latest lamp is just a fraction over the claimed 6W
according to my trusty Metrawatt analogue watt meter (using a jewellers
loupe to closely examine its mirror backed scale with one and two lamp
loadings).

Most of these LED lamps so often prove to have a significantly higher
consumption than claimed. I have a 12W 810lm lamp that actually takes 14
watts and typically see a half to 1 watt higher than claimed wattage for
most of the LEDs in the 5 to 10 watt consumption range that I've bothered
to test (which, to be fair, is most of them - once you have a trustworthy
watt meter to hand, every gadget becomes a test load[1])


I suspect when Philips first marketed their SL 'Comfort' 13 and 18
watt
range of CFLs, the industry wasn't facing any regulatory need to
specify the details of the "Incandescent GLS" reference lamp they were
pitting their product's performance against.

Quite possibly they were using a long life/rough service 220v (or
perhaps, the even lower efficacy 240v UK standard) filament lamp as
their "Standard", relying upon the characteristic 120% of "Design
Lumens" output from new of the fluorescent tube light output life curve
to help mask this discrepancy between these CFLs and regular 1000 hour
rated GLS 220/240 volt filament lamps.

I think the CFL claims were just bare faced lies on the part of the
marketing men and slimy salesmen.

That might be the truth of it as we, the aggrieved, see it but, in legal
terms, it's just a case of cunning wording designed (as always) for their
target audience to attach their own hopes and dreams onto (i.e. read more
into the advertising than is actually there, rather than analysing the
advertising blurb to discover what's *not* being said).

You have to remember (as everyone would no doubt be able to if only
"Cynicism 101" had been mandatory in the state education system) that
Advertising is essentially the art of "Lying by Omission" (to the maximum
extent permitted by law). Also, don't discount the fact that the highest
paid psychologists are largely employed by the major advertising agencies.


By the time LED lamp technology started to become a viable
alternative
to the CFL, Much tighter consumer protection regulations came into
force (presumably in the US of A judging by the use of the American
806lm 60W 120v 750 hour lamp standard chosen for the sale of LED lamps
claiming to have a 60W equivalency). It's for that reason alone that we
in the UK (and likewise for Europeans no doubt) have a much better
experience when upgrading old 60 and 100 watt incandescent GLS lamps
(even more so when replacing ageing CFL versions which claim the same
incandescent lamp wattage equivalence).

I think part of it is that there is a global standard now and US rules
based on their lower voltage incandescent filament bulbs have made LED
nominal equivalents brighter as a result. Thicker low voltage filament
can run hotter and be more efficient.

All helped by the choice of the shorter 750 hours lifetime rating
standard in the US of A (a legitimate choice to optimise the energy and
lamp costs for minimum TCO in a domestic setting).

Little wonder then that very few complain of failed expectations over
their light output. OTOH, the still relatively large number of complaints
over their disappointingly short lifetimes is easily explained by the
often thermally unkind fittings they get plugged into. However, as
further efficiency improvements continue to be made, even this complaint
will all but disappear as the relative amount of waste heat generated for
a given lumens output drops with each new generation of lamp that gets to
market.


The real benefit of efficiency improvements in LED lamp performance
lies
not so much with reduced electricity bills so much as being able to
upgrade from a 10W 810Lm LED to a 10W 1520Lm LED in a light fixture
that provides barely sufficient cooling for the 10W 810lm lamp with the
confidence that the newer brighter lamp will run just that little bit
cooler (and quite possibly realise the 25 to 30 thousand hour promises
typically made these days) since even less of that 10W input gets
turned into waste heat.

I think in an ideal world new LED luminaires should be designed to take
into account the strengths and weaknesses of the physical devices. This
is now happening but the change over will be slow. Some types of older
sealed glass bowl lamp shades spell a short hot life for LED bulbs.

The problem with that idea (effectively masking the downside of
inefficient LED lamps using specially designed but expensively
proprietary luminaires) is that it may retard the development of yet more
efficient lamps.

I'd prefer the LED manufacturers (essentially Cree Lighting these days)
to be lumbered with a motivation to produce LED GLS types that can
ultimately be used with such badly cooled lamp shades as you described to
the extent that replacement of even a 150W Tungsten filament light bulb
will become commonplace. Once that day arrives (perhaps in as short a
time as just 5 or 6 years), there won't be an existing GLS light fixture
that can't effectively be upgraded to LED.

[1] An effect reminiscent of the sentiment embodied in the following
saying:

"If the only tool you possess is a hammer, then every screw starts
looking like a nail."

--
Johnny B Good

On Thu, 16 Nov 2017 10:03:26 +0000, Clive Page wrote:

On 15/11/2017 13:48, Brian Reay wrote:
I'm unconvinced re LED lights in the domestic setting, not so much due
to the life (although it is good to see a seller honouring his
warranty) but more the light output.Â* We have them in our motorhome
and, in the confined space, they are OK. However, we tried them in the
kitchen (replacing some halogen bulbs - 2x40W halogen per fitting) and
with LEDs they were hopeless. I forget the rating of the LEDs but they
were, supposedly, equivalent to 40W bulbs. At a guess, they were more
like 25W.

It must depend on the type of bulb and the context, because I've found
the opposite. These 13W bulbs have a rated output of 1060 Lumens which
is supposed to be equivalent to 75W of incandescent filament. But I've
put them in places where there used to be 100W or even 150W
incandescents and found them adequate, because, I think, they are not as
omnidirectional. Since more of the light goes downwards which is where
we need it, the effective brightness is rather similar.

But one thing I forgot to mention: the replacement LED I got has an
almost identical box to the original except that (1) the price is 50%
higher, and (2) the guarantee has gone down from 3 years to 2.
Obviously I'm not the only one to have had a bulb fail after just over 2
years!

Well, 13W for a mere 1060lms is only 81.5 LPW, an efficiency level we've
put up with for almost 5 years now. Even Home Bargains offer a much
better 1520lm 12W "100W" lamp at a mere £2.99 in both LES and BC22 forms
with colour temperature options, from memory, of 2700K to 6500K[1].

If you can spare the odd 3 quid, it seems to me it would be worth your
while paying Home and Bargains a visit to pick up one of these lamps. Be
careful over the colour temperature choice though otherwise you might
grab a 6500K lamp by mistake which most of the population would deem a
little too cool (or thin) for comfort.

BTW, £18 for a mere 1060lm lamp is even more expensive than the price of
the 1600lm 12W LEDs being sold in Asda. Considering their competitive
pricing on general goods and produce, either their electrical buyer
doesn't keep abreast of LED technology developments and pricing or, more
likely, they're just taking the **** out of their customers with massive
mark ups on LED lamps.

Incidentally, you'll almost certainly see a much longer life if you
replace those 13W 1060lm lamps with the cheaper and brighter 12W 1520lm
Home Bargain lamps. Two reasons for longer life being 1 watt less input
power to start with and less of that energy being converted into waste
heat since more of it is used to generate light. In essence, a win-win
situation for a quarter of the original (or a sixth of the current) price
of those 13W LEDs you currently use.

[1] ISTR colour temperature options of 2700K and 6500K but I may be wrong
regarding the 2700K option, it might have been 3000K and there might also
have been a 4000K option which two options both tend to be more
acceptable by most than the extremes I quoted. You'll probably want to
avoid the 6500K (possibly 6000K) lamps as that tends to be a little too
'cool' for most people.

--
Johnny B Good

On 15/11/2017 13:48, Brian Reay wrote:
On 15/11/2017 12:18, Clive Page wrote:
Nearly 3 years ago I bought several 13W LED bulbs from Messrs Ryness
lighting in Old Compton St in London. They were expensive, £11-99
each, but I was reassured to see that they had a 3 year guarantee.

Last week one of the 3 started flickering: not a great loss of light
output, but very distracting to anyone using it and probably a sign
that it was about to fail. I had, being so doubtful about LEDs, kept
the receipt and dug it out to find it was only 2 years 11 months and
three weeks since purchase. So I took it back and I managed to
persuade the manager of Ryness to replace it. Even more amazingly,
the price of these has now gone up from nearly £12 to £18. Maybe
that's because so many have failed and had to be replaced. I have to
assume that the claimed lifetime of 50,000 hours (a decade or two at
our typical usage) is just a wild extrapolation from their testing
programme and wouldn't rely on that at all.



I'm unconvinced re LED lights in the domestic setting, not so much due
to the life (although it is good to see a seller honouring his warranty)
but more the light output. We have them in our motorhome and, in the
confined space, they are OK. However, we tried them in the kitchen
(replacing some halogen bulbs - 2x40W halogen per fitting) and with LEDs
they were hopeless. I forget the rating of the LEDs but they were,
supposedly, equivalent to 40W bulbs. At a guess, they were more like 25W.

So much depends on the actual LEDs in question I find. I have tried some
which were hopeless, and others which are properly equal to the halogens
they replaced. My kitchen was lit by 200W of halogen, and is now
brighter with ~36W of LED.


--
Cheers,

John.

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On 16/11/2017 12:34, Dave Liquorice wrote:
On Thu, 16 Nov 2017 11:57:22 +0000, Martin Brown wrote:

The 300Lm/W was achieved on a near infinite heatsink under perfect
laboratory conditions with a fabrication technique that doesn't easily
scale up - basically a one off research device made of unobtanium.

Around 130Lm/W is the current production device which is still
impressive and better than HPS (but still short of 220Lm/W LPS).

As far as what is on the shelves you're hard pushed to get over
100lm/Watt. I quite like the newer stick filament type, in standard
sort of clear envelopes not the fancy "period" ones. You have to
watch the power and lm numbers as not all are 100lm/W. The warm
white colour temperature is good, and light dispersion very similar
to perl tungsten. They don't appear to have any electronics either.
Not had this type long enough to comment on life.

By the time you include the control electronics and practical derating
to achieve lifetime that is about par for the course. They don't last as
long when run at absolute maximum ratings and a bit on the hot side.

The LED failures I've had have been the chips falling off the
board/heatsink...

I have had single LEDs in a chain fail and PSUs expire so far. None had
dropped off the board though - they just stopped conducting electricity.

--
Regards,
Martin Brown