"~misfit~" wrote in message
...
Once upon a time on usenet wrote:
Hi,

I am having the house rewired. In several places (kitchen, bathroom)
I am thinking of having inadequate pendant (?) or fluorescent tube
lighting replaced by low power LED bulbs, flush with the ceiling.
Now, LED bulbs I saw in the past looked ghastly, like car head
lights, lots of tiny spots of light. The electrician says he will
bring some samples. I get the impression the current LED lights have
a frosted cover to diffuse the LED light and the fixing is the same
"bayonet" fixing as the GU10 bulbs. Are there any drawback to these
LED bulbs? They are promoted as the solution to the energy crisis and
all other of society's ills, so I wonder how long before they become
yesterday's despised fad?.

Thanks,

Clive

My opinion for what it's worth is that the biggest problem with LED
lighting is people trying to retro-fit it into fittings deigned for
incandescant bulbs. The LEDS and their drivers tend to overheat and their
lives are consequently shortened considerably.

If you're getting the place rewired anyway I'd suggest getting LED lamps
fitted into the ceiling that have remote drivers and have finned heatsinks
in the ceiling space. I've seen them at a local hardware place and. while
they're not exactly cheap they should last 10 to 20 years

There isnt any evidence that stuff than needs fins does last anything like
that long.

and use ~20% of the electric that other options would.

On Sun, 06 Mar 2016 15:02:57 +1300, ~misfit~ wrote:

Once upon a time on usenet wrote:
Hi,

I am having the house rewired. In several places (kitchen, bathroom) I
am thinking of having inadequate pendant (?) or fluorescent tube
lighting replaced by low power LED bulbs, flush with the ceiling. Now,
LED bulbs I saw in the past looked ghastly, like car head lights, lots
of tiny spots of light. The electrician says he will bring some
samples. I get the impression the current LED lights have a frosted
cover to diffuse the LED light and the fixing is the same "bayonet"
fixing as the GU10 bulbs. Are there any drawback to these LED bulbs?
They are promoted as the solution to the energy crisis and all other of
society's ills, so I wonder how long before they become yesterday's
despised fad?.

Thanks,

Clive

My opinion for what it's worth is that the biggest problem with LED
lighting is people trying to retro-fit it into fittings deigned for
incandescant bulbs. The LEDS and their drivers tend to overheat and
their lives are consequently shortened considerably.

That's about the size of it with the current crop of 70 to 90 Lm per
watt lamps and the not so well ventilated luminaries (typically closed
off lamp shades that allow a warm blanket of air to surround the lamp).


If you're getting the place rewired anyway I'd suggest getting LED
lamps
fitted into the ceiling that have remote drivers and have finned
heatsinks in the ceiling space. I've seen them at a local hardware place
and. while they're not exactly cheap they should last 10 to 20 years and
use ~20% of the electric that other options would.

FWIW.

Well, quite!

Otoh, you could simply sit tight and use up your current stock of bulk
purchased CFLs until those 200Lm/W LEDs finally land on shop shelves as
promised 2 years ago by both Cree and Philips after they'd demonstrated
respectively 303Lm/W and 240Lm/W lamps in their laboratories claiming
that experience suggested it took some 18 to 24 months to go from 'Lab
Specimen' to 'Shop Product'.

At that time (2 years ago), the likes of Asda were routinely selling
81Lm/W LED lamps. The highest efficiency lamps on sale so far have barely
broken the 100Lm/W barrier so very little progress on the efficiency
front has taken place in all of that time.

I'm still hanging on for those 200Lm (and better) per watt LEDs simply
because such high efficiency lamps will then be able to match or exceed
lighting requirements from existing GLS luminaries with nowhere near the
same risk of overheating as the current crop of GLS LED lamps.

Thinking about it will reveal that doubling the efficiency from 90Lm/w
to just 180Lm/w not only halves the 16 watts consumed by a "100W
equivalent filament GLS lamp" down to 8 watts but also, of that 8 watts,
an even greater proportion is emitted as useful light, leaving even less
to be dissipated as unwanted heat.

Hanging on for the promised higher efficiency LED lamps not only offers
a very modest additional saving on the total household electricity bills
but, more importantly, it'll save you on the costs of fitting 'special'
luminaries (a win win scenario).

--
Johnny B Good

On 06/03/2016 12:18, Johnny B Good wrote:
I am having the house rewired. In several places (kitchen, bathroom) I
am thinking of having inadequate pendant (?) or fluorescent tube
lighting replaced by low power LED bulbs, flush with the ceiling.

For what it is worth I have just refurbed the shower room which had 4 x
halogen 60w bulbs, I replaced this with 2 LED 12 watt 6" panels as other
half wanted bright.
They are flush fitting to the ceiling and she is delighted with them, I
bought cheapo off ebay around £8 each. And so far so good.
I am now cosidering similar for the kitchen (24 feet) whereby I will
replace 9 halogen (540watts) with 5 LED panels (60watts)
I will do a temp hook up to ensure she likes before committing to
cutting holes in the ceiling.

On Mon, 07 Mar 2016 00:04:46 +0000, ss wrote:

On 06/03/2016 12:18, Johnny B Good wrote:
I am having the house rewired. In several places (kitchen, bathroom) I
am thinking of having inadequate pendant (?) or fluorescent tube
lighting replaced by low power LED bulbs, flush with the ceiling.

For what it is worth I have just refurbed the shower room which had 4 x
halogen 60w bulbs, I replaced this with 2 LED 12 watt 6" panels as other
half wanted bright.
They are flush fitting to the ceiling and she is delighted with them, I
bought cheapo off ebay around £8 each. And so far so good.
I am now cosidering similar for the kitchen (24 feet) whereby I will
replace 9 halogen (540watts) with 5 LED panels (60watts)
I will do a temp hook up to ensure she likes before committing to
cutting holes in the ceiling.

It looks like T/B has broken the attributions. None of the text you're
replying to belongs to me, it all belongs to "~misfit".

However, it does remind me that the four 35W halogen lamps flush fitted
into the ceiling of our shower room when it was refurbished about 5 years
ago have yet to fail. I suspect this longevity is due to my insistence
upon 12v lamps (with, as it happens, 60W rated smpsu "Transformers" which
exhibit current limiting to completely take the sting out of the switch
on surge). It's not the warmest room in the house so the 140W of radiant
heat is a welcome bonus. :-)

--
Johnny B Good

In article ,
Johnny B Good wrote:
However, it does remind me that the four 35W halogen lamps flush fitted
into the ceiling of our shower room when it was refurbished about 5
years ago have yet to fail. I suspect this longevity is due to my
insistence upon 12v lamps (with, as it happens, 60W rated smpsu
"Transformers" which exhibit current limiting to completely take the
sting out of the switch on surge). It's not the warmest room in the
house so the 140W of radiant heat is a welcome bonus. :-)

I've got all halogen in my lather large bathroom with home made shower
cubical. It's something like 7 years old - and have never replaced a bulb.
But with there being a fair amount of lighting in it, I only ever switch
them on when needed.

I would add the fittings (240v GU10) came from a shed, and the supplied
bulbs all failed very quickly. It's the replacements which have lasted
well. 'Bell' from TLC.

--
*If a pig loses its voice, is it disgruntled? *

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

On Mon, 07 Mar 2016 11:49:19 +0000, Dave Plowman (News) wrote:

In article ,
Johnny B Good wrote:
However, it does remind me that the four 35W halogen lamps flush
fitted
into the ceiling of our shower room when it was refurbished about 5
years ago have yet to fail. I suspect this longevity is due to my
insistence upon 12v lamps (with, as it happens, 60W rated smpsu
"Transformers" which exhibit current limiting to completely take the
sting out of the switch on surge). It's not the warmest room in the
house so the 140W of radiant heat is a welcome bonus. :-)

I've got all halogen in my lather large bathroom with home made shower
cubical. It's something like 7 years old - and have never replaced a
bulb.
But with there being a fair amount of lighting in it, I only ever switch
them on when needed.

Could that be as infrequent as just two or three times a week?


I would add the fittings (240v GU10) came from a shed, and the supplied
bulbs all failed very quickly. It's the replacements which have lasted
well. 'Bell' from TLC.

Seven years is a remarkably long time even for best possible quality 240
volt filament lamps (let alone 240v *halogen*[1] filament lamps) to
survive intact. I suppose a thousand one hourly lighting events is
possible with high quality 240v tungsten filament halogen lamps. You've
nursed those lamps very well indeed for them to have survived to such a
ripe old age. :-)

[1] "Quartz (normal soda lime glass isn't suited to the higher envelope
temperatures required to sustain the halogen cycle) Halogen" lamps use
the halogen to recycle the evaporated tungsten back onto the filament.
This isn't to extend filament life but to maintain light output by
preventing envelope blackening from tungsten vapour condensation.

The filaments still suffer selective thinning due to turn on surge,
especially true with the thinner and longer high voltage filaments.
Unfortunately, the halogen cycling doesn't provide much mitigation since
it redeposits the tungsten vapour onto the cooler parts of the filament
and its electrical connections and auxiliary support wires.

However, if a pdf on halogen lamps by GE is anything to go by, lifetime
hours ratings for halogen lamps varies anywhere from 100 to 6000 hours
but, in general lies in the range 2000 to 4000 hours regardless of
filament voltage and lumen output which seems totally counter to the laws
of physics as we understand them. Here's one little gem from this
document:

(http://www.google.co.uk/url?url=http...m/LightingWeb/
emea/images/
Halogen_Lamps_Spectrum_Catalogue_EN_tcm181-25047.pdf&rct=j&q=&esrc=s&sa=U&ved=0ahUKEwjM1ZSCga _LAhUEPBoKHZIYBAwQFggUMAA&usg=AFQjCNHYP2c4j9JVrIFn rd3lb35aZk4KSg)

which states "Incandescent and halogen lamps lose approximately 76% of
the input energy by radiating heat, and convert only 8% into useful
light."

Yeah, right! In your dreams, GE! The figures, more realistically, being
97 to 99 percent waste heat and 1 to 3 percent useful life at best.

I was simply looking for published information on halogen lamp life
ratings and came across what's quite obviously some 'tech' blurb written
by a 'Marketing Droid' with no understanding whatsoever of the laws of
physics, who has decided to tweak the figures "just a little", not
realising that 8% in this case isn't the tiny lie he's used to
perpetrating in ordinary advertising blurb but a massive 'Porky' in the
world of physics - Idiot!

Anyhow, it seems the lamp manufacturers can conjure up double the life
times "By the magical properties of Quartz and halogen" of the otherwise
'Humble' tungsten filament lamp and, in apparent defiance of the laws of
nature, make this independent of filament voltage (length) for a constant
lumen per watt output (there are some rather curious anomalies in the
specification tables provided for the different lamp types).

In short it looks like you could have doubled your 'Lighting Up
Events' (and run time hours) from my 2 to 3 a week 'guess' to more like 5
to 6 a week (assuming Sunday is 'a day of rest' for your lamps :-)
without reaching EoL with those extremely high quality lamps.

--
Johnny B Good

In article ,
Johnny B Good wrote:
I've got all halogen in my lather large bathroom with home made shower
cubical. It's something like 7 years old - and have never replaced a
bulb.
But with there being a fair amount of lighting in it, I only ever switch
them on when needed.

Could that be as infrequent as just two or three times a week?


;-) Several times a day. Every day of the week.

--
*A computer once beat me at chess, but it was no match for me at kickboxing.

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

On Mon, 07 Mar 2016 18:24:26 +0000, Dave Plowman (News) wrote:

In article ,
Johnny B Good wrote:
I've got all halogen in my lather large bathroom with home made
shower cubical. It's something like 7 years old - and have never
replaced a bulb.
But with there being a fair amount of lighting in it, I only ever
switch them on when needed.

Could that be as infrequent as just two or three times a week?


;-) Several times a day. Every day of the week.

And, they're definitely 240v filament lamps? If that's the case, it
bodes very well for my 12v lamps (extrapolation would suggest I'll never
have to replace a single lamp in *my* lifetime :-).

--
Johnny B Good

In article ,
Johnny B Good wrote:
On Mon, 07 Mar 2016 18:24:26 +0000, Dave Plowman (News) wrote:

In article ,
Johnny B Good wrote:
I've got all halogen in my lather large bathroom with home made
shower cubical. It's something like 7 years old - and have never
replaced a bulb.
But with there being a fair amount of lighting in it, I only ever
switch them on when needed.

Could that be as infrequent as just two or three times a week?


;-) Several times a day. Every day of the week.

And, they're definitely 240v filament lamps? If that's the case, it
bodes very well for my 12v lamps (extrapolation would suggest I'll never
have to replace a single lamp in *my* lifetime :-).

They are a mixture of GU10 and PAR 75 watt, all in downlighters. They are
fitted into a roof void where the insulation is well clear of them, so
probably run as cool as any. And no vibration from above.

Round the mirror I have golfball bulbs - dressing room style - and
although they are only switched on when needed, like shaving, have a very
short life. But do look pretty. ;-)

--
*Santa Claus has the right idea. Visit people only once a year.

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

In article , ~misfit~
writes
Once upon a time on usenet wrote:
Hi,

I am having the house rewired. In several places (kitchen, bathroom)
I am thinking of having inadequate pendant (?) or fluorescent tube
lighting replaced by low power LED bulbs, flush with the ceiling.
Now, LED bulbs I saw in the past looked ghastly, like car head
lights, lots of tiny spots of light. The electrician says he will
bring some samples. I get the impression the current LED lights have
a frosted cover to diffuse the LED light and the fixing is the same
"bayonet" fixing as the GU10 bulbs. Are there any drawback to these
LED bulbs? They are promoted as the solution to the energy crisis and
all other of society's ills, so I wonder how long before they become
yesterday's despised fad?.

Thanks,

Clive

My opinion for what it's worth is that the biggest problem with LED lighting
is people trying to retro-fit it into fittings deigned for incandescant
bulbs. The LEDS and their drivers tend to overheat and their lives are
consequently shortened considerably.

If you're getting the place rewired anyway I'd suggest getting LED lamps
fitted into the ceiling that have remote drivers and have finned heatsinks
in the ceiling space. I've seen them at a local hardware place and. while
they're not exactly cheap they should last 10 to 20 years and use ~20% of
the electric that other options would.

FWIW.
I have 4 PAR38s mounted in the kitchen ceiling. Currently I run 2
incandescent and 2 CFL. That way I save a bit of juice but still get
instant light when I switch on.
I've been looking at LED alternatives and noticed the better (More
expensive) ones seemed to have air vents around the periphery. (Not the
Diall ones in B&Q!!)
So presumably that is why and so do you think these would be OK to use
in these fittings?
--
bert