On 05/10/2013 10:15 AM, Nate Nagel wrote:
On 05/10/2013 09:52 AM, Nate Nagel wrote:
On 04/28/2013 06:11 PM, Tomsic wrote:
"Nate Nagel" wrote in message
...
--- SNIP ---
Has anyone seen any independent testing that supports b?
It seems like they will...
http://www.lightingprize.org/
http://www.lightingprize.org/60watttest.stm
In June 2010, the next stage of evaluation began: long-term lumen
maintenance testing. The 200 samples were sent to Pacific Northwest
National Laboratory to be tested in a new high-temperature testing
apparatus specifically designed for the L Prize competition and built
with assistance from Orb Optronix. The test bed was maintained at
45°C to simulate actual operating conditions and the lamps were
operated continuously. A movable integrating sphere (light
measurement device) took spectral measurements on each lamp every 100
hours for the first 3,000 hours of operation, and every 168 hours
(weekly) thereafter. Data for the first 7,000 hours of operation were
used to predict lumen maintenance of the lamps at 25,000 hours. With
95 percent confidence, lumen maintenance is predicted to be 97.1
percent* at 25,000 hours, which significantly exceeds the 70 percent
L Prize requirement.
So apparently all samples were proven to last at least 7K hours without
failure; it's apparently too soon to say whether they'll actually
last 25K
hours plus or not but it's not looking bad.
I know it sounds like I'm really pushing these bulbs but I'm not
affiliated with Philips or DoE in any way, I'm just a consumer who's
discovered a product that I really like and am kind of excited
about. I
wouldn't pay $50 for one of these bulbs, mostly because I don't have
the
money to be shelling out $50 for the equivalent of something that I can
buy for $2 give or take (in the form of a traditional incandescent)
but at
$15 you can make the argument that it will save money on air
conditioning
and electrical power, plus then you don't have to feel the guilt of
running big incandescents - not that I have in years; at my last
house the
only incandescents were in seldom used hallways and in the living
room and
kitchen where there were dimmer switches and I could not find any
acceptable more efficient solution (and yes, I have to admit, I did
feel
somewhat guilty about those...)
I'm also a little surprised that this is a Philips product. My money
would have been on Cree a few years ago, but it appears that the
commonly
available Cree incandescent light bulb replacements don't have either
the
efficiency or CRI of the Philips bulb. I haven't seen any of them in
operation so I can't comment how they stack up subjectively, but
they're
about $13 retail, dimmer, and have lower CRI (similar to the common
Philips LED "bulbs" that are actually easy to obtain) and a quick
google
did not yield data on where they're made, so I'm just ASSuming
China. So
unless someone who's spent more time geeking out on this subject than I
has data to the contrary, my (non-professional) opinion is that it's
worth
a little extra effort to search out the Philips L-prize bulb in
particular. However, I wouldn't be surprised if the Cree and older
Philips LEDs were still subjectively more pleasing than a typical
CFL. I
have a Utilitech 9W LED bulb that I bought last year when Lowe's had
them
on sale for $9 or so just out of curiosity, and I do find it
preferable to
CFLs and will continue to use it - but I'm sure that the CRI is
probably
around 80 and its color temp is a little higher than many people would
probably like.
While I'm rambling on on the subject, I'm tempted to try to hack
together
an adapter that will allow two bulbs to act like a 3-way incandescent,
because the very lamp that prompted that geekery is a 3-way socket and
they seem to still be very common, especially for table lamps which
may be
used for both ambient light and also reading. It wouldn't actually
work
exactly like a 3-way as I'd be using two bulbs of equivalent light
output
rather than one appx. twice as bright as the other, but I hope that
that
changes in the future (or, if CRI is less important to you, you could
use
some of the Cree bulbs or older design Philips bulbs which are
available
in multiple lumen ratings.) Or maybe in a few years we'll be able to
get
high quality, high output 3-way LED bulbs? I can only hope so.
nate
--
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According to a Philips Lighting speaker that I heard at a conference
recently, the high price of their "L Prize" bulb is due to (1) it's
made-in-the-USA costs which were a requirement of the DOE who
sponsored the
L Prize competition (2) the high 90+ color rendering index requirement
and
(3) the projected sales which are expected to be less than "commodity"
LED
bulbs with poorer performance and shorter life.
I'm not surprised by that at all...
but the 90+ CRI is one of the main reasons that I'm excited about this
bulb as opposed to the majority of other offerings on the market (the
other being the un-fudged lumen output for a "60W equivalent")
Late last year, the California Energy Commission adopted a ruling that
set
up performance specifications similar to the L Prize bulb. They're
called
"California Quality" requirements. The plan is to have the utilities in
California rebate only California Quality bulbs next year and to make
those
rebates substanial. It's interesting that the DOE and the CEC both feel
that the quality of light (good color, high light output, long life) are
important if consumers are to accept them. Reading about all of the
poor
performing bulb products on this ng, including the sad stories about
CFLs,
it seems about time that we have quality products that offer value if
we're
ever to replace the energy-wasting incandescent bulbs.
Ayup, but I have a feeling that this bulb will quietly disappear after a
while. "California Quality" I think the L-prize fails because of
its poor power factor.
http://www.ledjournal.com/main/blogs...lity-led-bulb/
The Cree bulbs, which are the ones that HD is pushing now, seem
decent-ish but have a published CRI that doesn't meet the specs, and
some have reported a detectable flicker, BUT the do have power factor
correction. So there's apparently no "perfect" bulb on the market,
although the L-prize bulb with power factor correction would be pretty
darn close.
nate
found he
http://www.lightingfacts.com/products
looks like there is now exactly one other high CRI standard form factor
bulb on the market
http://lednovation.com/products/pdf/..._spec_revE.pdf
which does in fact also have a high power factor.
unfortunately, a web search reveals that it is expensive (shocker!) out
of stock at all of the few places I checked (I didn't spend a lot of
time on this though) and one amazon review mentioned an audible buzz.
But we're getting there...
nate
And this is all irrelevant anyway because as I feared, apparently the
L-prize bulb is no more. I don't have 100% confirmation yet but they're
out of stock everywhere and wikipedia is saying they've been
discontinued. I dropped a line to Philips asking where I could buy
them, but I suspect that this was a premium product being sold at or
below cost and once Philips sold enough to demonstrate that they could
make them they're going to now quietly drop them and concentrate on
similar but not quite as good products that they can make more profit on.
I got six, now I'm wishing I'd picked up more of them.
nate
--
replace "roosters" with "cox" to reply.
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