Re: Long Live the Incandescent!

[Marc_F_Hult <MFHult@xxxxxxxxxxxxxxxxxxxxx>]

On Sat, 18 Jul 2009 16:44:07 -0700 (PDT), John M <2ac16mo@xxxxxxxxx> wrote in
message  <350dc051-02f2-4c16-b1d2-9959369996e3@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>:

>I can see a relatively quick payback for these Cree LR6C lamps in a
>commercial/industrial application, but for a home where they may not
>be used more than an hour or two per day the payback would be many
>years, unless they get the price down.

Our kitchen lights are not only the longest of any main interior light, they
had the highest power use before I switched to a mixture of incandescents and
LEDs ( 9 x 120watts = 1080 watts)

>On my visit to the Cree web site I didn't see any mention of dimming
>capabilities.

Note that the company has both www.cree.com and www.creelighting.com sites
with limited linking between the two. Residential products are primarily at
creelighting.com not cree.com

Dimming is variously listed at 20% and 25% ; Also power factor > 0.9
http://www.creelighting.com/downloads/LR6.pdf
http://www.creelighting.com/downloads/LR5.pdf
http://www.creelighting.com/downloads/LR4.pdf

I use DMX/analog-controlled dimmers with large inductors (chokes) mounted in
a panel in the basement for the kitchen lights, but Cree lists compatible
conventional dimmers:
http://www.creelighting.com/downloads/Dimmer_Compatibility_Rev011608.pdf

Lutron also has tested and recommends many of their dimmers with Cree lamps:
http://www.creelighting.com/downloads.htm

>And lastly, I hope they do a better job of living up to the claimed
>life expectancy than CFL's did.

Time will tell but the signs are propitious. The vulnerability of LEDs is
similar to that of CFLs in that it appears that a common failure mode of CFLs
is for the electronic circuitry to be cooked and then die and LEDs also
require at least some electronic components when used directly with AC
sources.  Many of the failures of CFLs have been in base-up or enclosed
environments. (Remember the X-10 "socket rocket" and its short life when used
in base-up orientation ?) But Cree has designed their units for specific
orientation, geometry, and environment, namely 4", 5" and 6" ceiling cans and
so has theoretical  and empirical knowledge of the heat production and
temperature distribution in normal, code-compliant use.


>One place I would really like to incorporate LED lamps is under our
>kitchen cabinets.  I presently use inc. rope lights above the cabinets
>and halogen under the cabinets.  These new LED strips are interesting,
>but they all have bulky power supplies to deal with.  Have you used
>any undercabinet LED's Marc?

Funny you should ask.  ABIR, in decades of putting up with my HA experiments,
my better half has never actually made a specific request until recently --
namely to illuminate the dark space under the black steel shelf I installed
for the black microwave and touch screen where the black coffee-making
gadgets are stored next to the black soapstone back splash. (OK. So I created
this black hole and now have to deal with it ;-) No progress or decisions
yet. I am (unduly?) fascinated by the potential for RGB and RGBY LEDs.

... Marc
Marc_F_Hult
www.ECOntrol.org