We have been developing LED in-case lighting at Shelburne Museum for the
last four years. We installed over 200 multiple LED assemblies to light our
doll collection in 2003, over 150 to light toys in 2004, and over 50 to
light miniature interiors and samplers in 2006. From my experience, I
believe that they are the light of the future that will replace both
tungsten and fluorescent lights in museums and our homes.

The advantages for in-case lighting especially are many: low heat, low or no
UV, adjustable light levels, directed light so that light is not wasted
illuminating the whole case instead of just the artifacts, decent CRI (and
getting better, especially the white LED's that use phosphor coatings), very
low energy use (they use less energy than the fluorescents we replaced in
the doll cases), low maintenance (no bulbs to replace), long life, and a
reasonable price (much less expensive that fiber-optics).

For all their advantages, the perfect off-the-shelf LED museum light is not
yet readily available, although a few are quite close. As manufacturers
attempt to make LED's brighter, they get hotter. The heat build-up can
shorten life. The first generation LED case light we installed in the doll
cases boasted a life of 35,000 hours, or about 30 years of our exhibition
time which is around 1200 hours/year. After only 2 years, they had lost
50-70% of their illumination. Fortunately, the manufacturer had guaranteed
them for 10-15 years and they will all be replaced with a better LED
assembly, but we will have to install the replacements which will take
significant time. Also, the color temperatures were inconsistent.

A second generation LED that was installed in the Toy Shop that has a better
CRI that is consistent from batch to batch. These LED's, made by a different
manufacturer than those in the doll cases, are also holding their
illumination quite well. 

A third generation LED assembly will soon replace the doll case LED's.
Because they are about 4 times as bright as the 1st generation, dimmers will
need to be installed to decrease light in the cases to a safe level.
However, if they do dim over time, we can simply turn them up, so they
should last even longer than anticipated for our purposes.

Overall, we are quite pleased with the LED's we are using at Shelburne.
However, it has taken a lot of work to get it right. One of the reasons for
this post is so that others do not have to repeat our work when choosing LED's. 

Some advice:
(1) Check out ASSIST (The Alliance for Solid-State Illumination Systems and
Technologies) information published by the Lighting Research Center at
Rensselaer Polytechnic Institute http://www.lrc.rpi.edu/programs/solidstate/
. Only buy from manufacturers who adopt ASSIST recommendations on useful LED
life (cannot dim more than 30% over advertised life). (2) Work with a
reliable manufacturer. Do not just order LED's from internet vendors (except
to experiment with). (3) Get a good warrantee--at least 10 years, try for
15. If the manufacturer is advertising a 35,000 hr life, they should be
willing to warrantee to at least 20,000 hrs. (4) Do full-scale mock-ups
before committing to a lighting product. Make sure you involve everyone with
a stake in the outcome, curators, conservators, directors, exhibit
personnel, electricians. This applies to any lighting system to be used in
museums. 

Finally, there is an LED museum track-light system that will soon be
commercially available from LSI (Lighting Services Incorporated). Called the
LumeLEX Series, it is very impressive. The cost also leaves a lasting
impression. www.lightingservicesinc.com

Anyone seriously considering LED's for in-case lighting is welcome to
contact me off list.

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