Incandescent Bulbs Free to Good Home
W4KRL at arrl.net
Fri May 25 11:38:55 CDT 2012
We recently remodeled our kitchen and happily threw the 2x40 fluorescent fixture in the trash. I used 4-inch recessed fixtures with Sylvania LED adapters model 70658 at $40 each. They produce 550 lumens on 9 W at 3000K which is a very attractive light and I see no undesirable color distortion. A CFL/LED rated dimmer provides practically full range dimming although they will not start when less than half dimmed. A nice feature of LEDs over incandescent is that they stay the same color as they are dimmed.
I use EcoSmart 13W 850 lumen LEDs in pendants at $24 each. Also 3000K. They have an odd shaped top that provides even lighting over nearly 360 degrees. I much prefer them to the Philips because they are white when turned off, not the strange yellow of the Philips. Also cost only 1/3 the cost of the Philips.
Bottom line is I spent $450 on light bulbs which is staggering except when compared to the cost of the remodel. I feel the LEDs produce superior light to incandescents and I will never go back. I will probably replace my CFLs with LEDs as they fail.
I do have an RFI problem with a $10 bulb beside my bedside FM radio. Never had this problem with the CFLs.
I started a notebook with UPC labels and copies of the bills and warranty statements as I share your skepticism on the claimed life.
I’m also experimenting with LED replacements for my walkway mushroom lights. So far I haven’t found a satisfactory combination of color and brightness.
73 Karl W4KRL
From: Mike ODELL [mailto:mo at ccr.org]
Sent: Friday, May 25, 2012 12:44 AM
To: W4KRL at arrl.net
Cc: Tacos AMRAD
Subject: Re: Incandescent Bulbs Free to Good Home
The alleged efficiency of LED household lighting ignores
the huge amount of energy required to fabricate LEDs and
their associated integrated circuit controllers, including the
wafer substrates which are "raw material" for the device fab.
There are several big problems with LEDs as general purpose lighting.
(1) while the efficiency is good, the actual absolute output is low, and
(2) it is a highly directional point source. That means it is very hard to
get wide field lighting we want and need for most human activities.
(3) a sufficiently large percentage of lights are on triac
dimmers and "incandescent equivalent" behavior is require
To win those sockets. This dramatically complicates the driver IC and
can aggravate the thermal management issues.
(4) color rendering is still challenging. Producing "warm white" at the color temps
Required can be done well, or it can be done cheaply. The new Phillips bulb
which won the DoE contest uses an external phosphor system integrated
with the diffuser used to create even light with good color rendering
from raw high-output die LEDs. It is not cheap but it is impressive.
(5) the lifetime claims for LED residential lighting are simply fantasy. Nobody has demonstrated
anything close to the often-quoted numbers with LEDs in real housings in
real fixtures running at real temperatures, even ignoring the case of being backed-up to attic
spaces in the Southwest well north of 125F on a hot day.
I like the prospect of LED lighting for some purposes. I use it in my boat now where the
raw efficiency is a large enough win to swamp everything else and the simple PWM
dimmers on the 24vdc supply work fine with the simple constant current drivers in the
replacements for the bi-pin G4 xenon incandescent bulbs. as for residential lighting,
any new build should seriously consider designing with the new integrate luminaires
which avoid almost all of the retrofit problems. But existing houses? it's a tough sell because
the retrofit approach doesn't yet work very well ignoring cost, but when you add the
economics, it's really just going to piss people off. It's another version of the 55mph
speed limit - only less well-considered because at least all the cars would do 55mph
even if everyone rebelled at doing it. At the moment, there is not a residential
LED lighting technology which is ready for mass deployment by the general public.
Attempting to force the issue will end badly just like it always does.
Btw - nobody on this list qualifies as "general public" when it comes to adopting technology.
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the Tacos