Strange problem with low energy light bulb

[Eeyore]

"Richard Crowley" wrote in message

Sure, if your object is to confuse people, then not spelling out exactly
what you mean is a great way to do it.

It is a good point though.

Graham

 

[Mr.T]

There are plenty of countries where you'll find an ambient temp close to 40C.
Imagine they want CFLs too.

I imagine they want house cooling too.

MrT.

 

[Ken]

"Phillips"

Philips

 

[Eeyore]

"Eeyore" wrote


I imagine they want house cooling too.

LOL !

You need to get out a bit.

Graham

 

[Arny Krueger]

Well, they *are* dimmer than conventional incandescents.
I've always found the idea that they use 1/5 the power
misleading. Those comparisons were made with 'softone'
bulbs.

You need at least a 23W CFL to match the output of a 100W
incandescent.

The table here...
http://en.wikipedia.org/wiki/Incandescent_lamp#Power

Shows a 100W incandescent providing 1700 lumens.

In comparison some new CFLs I have claim only 1100 lumens
for an 18W and 1200 lumens for a 20W.

The 11W CFLs claim 600 lumens and that makes them only
slightly brighter than a standard 40W bulb instead of
equivalent to a 60W as claimed.

My searching finds ordinary 40 watt bulbs rated at from 280 to 355 lumens.
More lumens at a given wattage rating generally means a shorter life. IME
incadescent lights draw significantly less than their rated power, so their
light output may also be less than spec.

280 to 355 lumens is about half the light output of a 11 watt CFL. BTW, my
experience with CFLs pretty well matches the lumen output levels that you've
mentioned, Graham.

About twice the brightness from about one quarter the power works for me!

We've seen vastly improved bulb life, which is especially helpful when bulbs
are located where they are hard to replace, such as at the top of a 3-story
stairwell.

My first project was in a large basement room that was frying about one
halogen bulb (of 32) per week, partially due to overheated fixtures. We
pretty much relamped the room almost twice a year. We put in 2 CFL bulbs
per fixture and still dropped the fixture's internal temperature to under
110 degrees F from more like 140. Lumen output per fixture almost tripled.
We were also able to get a more pleasing color temperature. This room is has
been relamped for about 3 years. We are currently replacing about one bulb
per year.

I've done a fair number of fairly large (i.e., 8 or more bulbs per room)
incadescent (mostly halogen) to CFL upgrades, with extremely positive
results. In every case the fixtures were previously loaded up with
incadescent bulbs rated at the fixture's maximum power. They were providing
poor to marginal lighting.

When I can maintain the power usage at a constant level, the results of the
CFL upgrades are brilliant. When I'm forced to run the fixture at reduced
power levels because of bulb space limitations, the results are still
striking and very helpful.

The building in question had lighting engineered to 1950's standards. The
lighting had become ineffective because of rising expectations. Actually
upgrading the fixtures would have been prohibitively expensive.

 

[[email protected]]

I'm certainly puzzled by the +/- 28% bit !

Yikes!

In general, CFL lamps operate at somewhere between 23 and 29% of the
power requirements of an incandescent for the same average output in
lumens. Most that I use operate at 28%. So, I picked that figure.

Given time-in-service, all the CFLs & PLs we have in service have more
than covered their costs when compared to incandescents. So, any
future life we get out of them is at the 28% figure. If one measures
in the same way that one "saves" when purchasing items "on sale", we
are operating for free....

Semantics.

Peter Wieck
Wyncote, PA

 

[[email protected]]

Yes I did, maybe you missed it.


So true!


Your name calling does not make you the sole person responsible for setting
discussion parameters on Usenet.

When *I* make a choice, I do not eliminate the best options just because
they don't suit YOUR arguments.

MrT.

Yes, when "you" make a choice... but this thread is not one comparing
CFL lamps to standard tube-types. You may choose to argue on a
tangent, that is your privilege and absolute right. That is irrelevant
is mere accident, of course. And to use that particular argument to
condemn an entire species is, with respect, stupid.

Peter Wieck
Wyncote, PA

 

[Don Pearce]

Yikes!

In general, CFL lamps operate at somewhere between 23 and 29% of the
power requirements of an incandescent for the same average output in
lumens. Most that I use operate at 28%. So, I picked that figure.

But you said +/- 28%. That means between 72% and 128%.

d

 

[[email protected]]

But you said +/- 28%. That means between 72% and 128%.

d

Um.... we are operating at 28% of incandescent costs, plus 1 minus 5.

Or, we are operating +1%/-5% 28% of incandescent costs.

All in how it is parsed. I can see your point, however.

Peter Wieck
Wyncote, PA

 

[Bob Urz]

My searching finds ordinary 40 watt bulbs rated at from 280 to 355 lumens.
More lumens at a given wattage rating generally means a shorter life. IME
incadescent lights draw significantly less than their rated power, so their
light output may also be less than spec.

280 to 355 lumens is about half the light output of a 11 watt CFL. BTW, my
experience with CFLs pretty well matches the lumen output levels that you've
mentioned, Graham.

About twice the brightness from about one quarter the power works for me!

We've seen vastly improved bulb life, which is especially helpful when bulbs
are located where they are hard to replace, such as at the top of a 3-story
stairwell.

My first project was in a large basement room that was frying about one
halogen bulb (of 32) per week, partially due to overheated fixtures. We
pretty much relamped the room almost twice a year. We put in 2 CFL bulbs
per fixture and still dropped the fixture's internal temperature to under
110 degrees F from more like 140. Lumen output per fixture almost tripled.
We were also able to get a more pleasing color temperature. This room is has
been relamped for about 3 years. We are currently replacing about one bulb
per year.

The future in lighting is LED's. They are already working on halogen MSR
replacements with LED's. LED technology has come a long way in the last
5 years on high output units and modules. Most truck trailers and even
traffic lights are going to LED units now. LED lighting may not displace
florescent's, but it will be used right along side them in some
applications.

I am also convinced that an occasional use lamps in a closet or such
won't cost justify CFL conversion. Its false economy if it takes 40
years to cost benefit from it.


Bob

 

[Arny Krueger]

The future in lighting is LED's.

Could be.

Woe be onto us if we have jobs to get done today, and for a reasonable cost.

They are already working
on halogen MSR replacements with LED's.

Yup, I'll replace every MSR lamp at home and at church with arrays of LEDs.
Right now!

LED technology
has come a long way in the last 5 years on high output
units and modules.

If its going to be cost-effective it is going to have to go a long way
further.

Most truck trailers and even traffic lights are going to LED units now.
LED lighting
may not displace florescent's, but it will be used right
along side them in some applications.

LEDs are easier to cost-justify if they are bouncing down the road.

I am also convinced that an occasional use lamps in a
closet or such won't cost justify CFL conversion. Its false economy if
it takes 40 years to cost benefit from it.

Note that none of the applications I mentioned were justified based on just
the power used.

 

[[email protected]]

Issues with LEDs today:

Color rendering
Diffusion

Once those are solved effectively, they will be excellent
alternatives. My guess is 5 years to color rendering, and 5 more to
diffusion. Most LEDs today filter a single color to a specific
monochromatic output. Even the LED-type flashlights are very heavily
skewed to the blue end of the spectrum in order to get sufficient
brightness, and require multiple LEDs to get even a minor beam with
very poor diffusion.

Peter Wieck
Wyncote, PA

 

[[email protected]]

I am also convinced that an occasional use lamps in a closet or such
won't cost justify CFL conversion. Its false economy if it takes 40
years to cost benefit from it.

As to this particular issue: Just replace the incandescent when it
fails with a CFL. Point being that you will use less power, which will
not get any cheaper, and eventually there will be a benefit. Taken
further, replace the heaviest-use lamps and rotate those incadescents
into that closet until they all have failed. Pretty simple at that.

Peter Wieck
Wyncote, PA

 

[Albert Manfredi]

Issues with LEDs today:

Color rendering
Diffusion

Once those are solved effectively, they will be excellent
alternatives. My guess is 5 years to color rendering, and 5 more to
diffusion. Most LEDs today filter a single color to a specific
monochromatic output. Even the LED-type flashlights are very heavily
skewed to the blue end of the spectrum in order to get sufficient
brightness, and require multiple LEDs to get even a minor beam with
very poor diffusion.

But you can use a combination of red, green, and blue high intensity
LEDs, to create any variant of "white" that you prefer. From what Ive
read so far, the efficiency of the new high intensity LEDs is almost
identical now to that of CFLs, which means about the same lumens for 1/4
or 1/5th the power of an equally bright incandescent bulb.

I think we shouldn't get stuck on any supposed problem with CFLs, as if
they are the only alternative here.

The weird thing about LEDs is that they would last such a long time that
they wouldn't need replacement. In principle, you can build them right
into the lamp itself. Or in walls, or whatever.

Bert

 

[Arfa Daily]

But you can use a combination of red, green, and blue high intensity LEDs,
to create any variant of "white" that you prefer. From what Ive read so
far, the efficiency of the new high intensity LEDs is almost identical now
to that of CFLs, which means about the same lumens for 1/4 or 1/5th the
power of an equally bright incandescent bulb.

I think we shouldn't get stuck on any supposed problem with CFLs, as if
they are the only alternative here.

The weird thing about LEDs is that they would last such a long time that
they wouldn't need replacement. In principle, you can build them right
into the lamp itself. Or in walls, or whatever.

Bert

The length of service issue with LEDs is very dependant on the way they are
driven, if you are to get the maximum of 100,000 hours plus out of them.
However, that said, even if not driven properly - ie not pulsed - from what
I have read, they are still good for 40k hours, before the light output has
dropped by 50%. As far as colour rendering goes, I agree that this can be
achieved with combinations of RGB LEDs, and I'm sure can be made as good or
better now, as CFLs are ( not that I'm saying theat CFLs are good of course
.... !) Just a few days ago, I saw somewhere that one of the manufacturers
has come up with LED chips bonded to a sort of 'ball on a stick' shape, so
many small chips face in virtually every direction around a sphere, to get
over the point-source poor beamwidth issue.

BTW, Philips CFLs = China ? Not any more, it would seem. I picked one up in
the supermarket tonight to have a look. It said " Made in Poland " ...

Arfa

 

[Don Pearce]

The length of service issue with LEDs is very dependant on the way they are
driven, if you are to get the maximum of 100,000 hours plus out of them.
However, that said, even if not driven properly - ie not pulsed - from what
I have read, they are still good for 40k hours, before the light output has
dropped by 50%. As far as colour rendering goes, I agree that this can be
achieved with combinations of RGB LEDs, and I'm sure can be made as good or
better now, as CFLs are ( not that I'm saying theat CFLs are good of course
... !) Just a few days ago, I saw somewhere that one of the manufacturers
has come up with LED chips bonded to a sort of 'ball on a stick' shape, so
many small chips face in virtually every direction around a sphere, to get
over the point-source poor beamwidth issue.

BTW, Philips CFLs = China ? Not any more, it would seem. I picked one up in
the supermarket tonight to have a look. It said " Made in Poland " ...

Arfa

Currently, white LEDs are in fact blue LEDs coated with a fluorescent
substance, so probably the overall light quality will be quite similar
to CFL.

d

 

[Arfa Daily]

Currently, white LEDs are in fact blue LEDs coated with a fluorescent
substance, so probably the overall light quality will be quite similar
to CFL.

d

Hi Don

I just went looking at some of the latest LED technology, and they are now
producing LED chips that have an array of alternate red and blue die
'stripes', each made up of a string of individual dies, with the whole
overlaid with a yellow phosphor. By altering the colour of the phosphor,
they can set the colour temperature to any value they like and, it is
claimed, with a colour rendition index of 90 or better, so it seems that the
colour rendition issue with LED 'light bulbs' is a lot closer to being fully
resolved, than the 5 years that was postulated in one of the above posts. If
this is the case, and the field of LED lighting contnues to advance at the
pace that it has over the last say 3 years, then I would suggest that the
CFL has a very limited future ...

Arfa

Arfa

 

[Bob Urz]

Issues with LEDs today:

Color rendering
Diffusion

Once those are solved effectively, they will be excellent
alternatives. My guess is 5 years to color rendering, and 5 more to
diffusion. Most LEDs today filter a single color to a specific
monochromatic output. Even the LED-type flashlights are very heavily
skewed to the blue end of the spectrum in order to get sufficient
brightness, and require multiple LEDs to get even a minor beam with
very poor diffusion.

Peter Wieck
Wyncote, PA

http://members.shaw.ca/sagelighting/led_spotlights_and_bulbs_specifi.htm

http://www.electronicproducts.com/ShowPage.asp?Filename=hlap01.jun2006.html

http://www.californiagreensolutions.com/cgi-bin/gt/tpl.h,content=270

http://www.ledsmagazine.com/news/4/1/4

http://www.mew.co.jp/e-tecrepo/531e/main02.html
http://www.mew.co.jp/e/corp/news/2006/0603-01.htm

http://www.eetimes.com/showArticle.jhtml?articleID=181503227

Bob

 

[James Sweet]

Currently, white LEDs are in fact blue LEDs coated with a fluorescent
substance, so probably the overall light quality will be quite similar
to CFL.

It's not, the phosphor is not the same as used in a CFL, and the light
output is dominated by the blue from the LED chip. Another problem with them
is that they shift blue as the phosphor ages. They're improving, but still
far from perfect. There's a lot of Chinese crap LEDs on the market now too
that are noticeably inferior to good name brand ones. I had some bargain
white LEDs that got dim and blue after only about 2 months of continuous use
and that was driven below spec.

 

[John Doe]

But you can use a combination of red, green, and blue high intensity
LEDs, to create any variant of "white" that you prefer. From what
Ive read so far, the efficiency of the new high intensity LEDs is
almost identical now to that of CFLs, which means about the same
lumens for 1/4 or 1/5th the power of an equally bright incandescent
bulb.

Don't believe everything you read.

Experience is the best teacher.

In other words, LEDs suck for bright light sources.

However, the hype is good for selling them to fools over the
TV/Internet. Like that one guy selling LED light bulbs on TV (USA). He
doesn't explicitly say that they're bright as a lightbulb, but they
are in a lightbulb package and used in the commercial as if they were
a lightbulb. Some people probably fall for that.

The weird thing about LEDs is that they would last such a long time
that they wouldn't need replacement. In principle, you can build
them right into the lamp itself. Or in walls, or whatever.

Right, but pointless except for low light applications.