My attention has just been drawn to the following document:
Note that although the original report is older, this .PDF includes
supplements through 2005.
This seems to show that Osram/Sylvania have the shortest life and a
significant deterioration in light output during that short life,
GE appear to be the best. I think they are available at Wal-Mart and
Probably true that a lot has changed since 2005. But most of the CFLs
I've bought have been Sylvania, and they haven't lasted particularly
long. Perhaps that's a Sylvania thing: I had some Sylvania incandescents
that popped as soon as I switched on and at least on more out of the
same pack that lasted only a couple of days.
I have just bought some "Lights of America" brand 45-watt-equivalent LED
bulbs (power consumption only 3.5W) intended for use in accent lights: a
nice white light and no warm-up delay.
On Sat, 17 Jan 2009 22:03:45 -0500, "Percival P. Cassidy"
Where did you buy those LED lights? Do they screw into a standard
socket? I have horses in a barn and have a 10watt CFL (equal to 40W)
security light which is on all the time (so the horses can see). I
guess 240W per day is not too bad on the electric bill, but the CFLs
get very dim in cold weather, and when our recent cold spell dropped
to MINUS 39F, it was so dim I could only see a dull glow, and then it
burned out. I replaced it, and it was so dim I could not see
anything. I finally replaced it with a smaller incandescent.
I'd like to cut down power usage, as well as eliminating this dimming
problem in the cold. Besides that, I was told NOT to use a light
sensor to shut off the power during the day (on a CFL), because when
they turn on and off, they are not putting out full power for a minute
or two (like a dimmer), and that will destroy a CFL quickly. I'm sure
a LED would not be affected by that, so I can save even more power.
Using 10W CFLs 24/7 for one year is 87,600 watts.
If those LEDs use 3.5 W and I could put on a sensor, so it would only
be on about 12 hours per day (average), that would only be 15,330
watts per year. Quite a savings.
I really cannot see how you could justify the bulb change based on cost.
At $0.15/kWh the 87600 watt hours you use in a year only costs about
$13.00. Changing to the LED's would lower this to about $2.30. Hardly
worth a trip to the store.
EJ in NJ
Based entirely on cost of energy, you are right, even though all these
things do add up. But based on the poor performance in cold weather,
it's definately worth changing. Plus, right now, I am using an
incandescent bulb and that is costing more. It's just too cold to get
any light out of the CFL. Also, I have had to replace this bulb about
once a year. I know they are only $5 or less, but if a LED costs $10
or even $20, I know they last almost forever.
Actually, I bought a string of white LED Christmas lights after
christmas for less than half price. I was wondering how much light
that would produce. It's not handy, but I think that has about 30
LEDs and said it used about 3 watts. I have not yet tried it, it's
been too cold to piss around outdoors. I figured I'd find some use
for it, for the couple bucks it cost.
Lights of America products are typically poorly engineered junk. Also beware
of cheap LED lights. They will fade within a few hundred hours of use. These
are the type made from clusters of those 5mm indicatoer style LEDs. The
bulbs are usually under $25. The only good LED bulbs are expensive and use
high power LEDs, like the Cree XR-E emitter.
My experience with Lights of America (though mostly not buying much from
them since 2002 due to disappointments) is early failure.
White low power LEDs have low usage as indicator lights, and they are
likely to run into fading issues there unless seriously underpowered.
Keep in mind that most modern white LEDs are plenty bright enough for
use as indicator lights at 3-4 milliamps, 15-20% of the 20 milliamps that
most "low power" LEDs have their specified performance dependent on. Keep
in mind how glaringly bright most modern white low power LEDs are at 20 mA
- they will put spots in your eyes!
- Don Klipstein ( firstname.lastname@example.org)
I picked up a pack of those LED lamps to fiddle with. Some notes:
- The light is not "nice white", it is notably bluish like most "white"
- The color temp is not consistent between lamps, particularly if they
have had different run times.
- LEDs produce less lumens per Watt than CFLs, so they are less
efficient. Being directional they can allow a lower Wattage to be used
for task lighting however.
- Those particular lamps don't go off when you turn them off, they
continue to produce very low level light for several minutes.
I did a comparison in a wall wash type application between those LED
lamps, a 14W CFL and a 50W encapsulated halogen and the CFL won for best
overall results. The LED lamps are still interesting to fiddle with.
lets see I have a CFL in my pole lamp controlled by a lamp sensor and
timer. its off from midnite to 6AM on any other time its dark enough,
occasionally tripsa on in mid day during a storm.
this CFL dies on average once a year, wierdly when I used incandescent
bulbs they died more often but were a lot cheaper.
but CFL failure doesnt appear to take out the light sensor:) they are
so the CFL is affordable, by saving bucks on energy and lamp sensors.
bought a LED night light, way too blue, its nifty but not ready for
On Sun, 18 Jan 2009 08:38:20 -0800 (PST), " email@example.com"
Yes, I know the white ones are a bluish tint. I got some of those
headlamps and flashlights.
One thing I always wonder, I noticed that most of the Christmas LEDs
have a colored shell. I know a LED can create red, for example,
because I have seen clear shells that are red, or green, or whatever.
But I wonder if these colored ones with colored shells are not just
white and the shell makes the color?
Yes, I have considered a timer rather than a sensor. I'd have to
change the settings regularly. Not that big of a deal, but at the
same time I know timer motors consume energy too, so it might not be
I have done some experimenting with LED lighting and found they are
most useful for when they reall only have to be seen instead of
illuminating any particular area. I am using some for stairwell lights
and they work great for that. I was very disapponted in the counter
top lamps I installed. The counter top lamps do make decent night
lights so I kept them and added some flourescent work lights beneath
the kitchen cabinets. A florescent fixture that also contains some
LEDs may be interesting.
The comparitive test if it is one is old, www.popmechanicsmag.com
consumers reports, are more up to date. I use HD with a 7 yr warranty
and color is tops. Try HD Invision brand they last in commercial use.
Soft White is like incandesant
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