Re: MR16 LEDs for Landscape Lights

["Robert Green" <ROBERT_GREEN1963@xxxxxxxxx>]

"Jeff Volp" <JeffVolp@xxxxxxx> wrote in message
news:qKE7k.66261$102.47858@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> In a quest to become even more energy efficient, I am looking at replacing
> the 20W halogens in our landscape lights with MR16 LEDs.  While the LEDs
are
> incredibly expensive compared with halogens, payback through energy
savings
> should be achievable in several years.  Searching the web I found
relatively
> little information regarding how well these units actually work in real
> applications.  So, I thought I would see if anyone here would have some
> comments.
>
> I have several concerns.  First, it appears that output and life are
> negatively impacted by temperature.  Since these outdoor fixtures are
pretty
> much sealed except for a drain hole, conduction cooling for the higher
> wattage LEDs will be a problem.  That caused me to rule out several of the
> higher output units.  The design of the fixture requires a wide-angle
lamp.
> One of the best candidates so far is this one:
>
> http://www.ledwholesalers.com/store/index.php?act=viewProd&productId=322
>
> I have also been looking at the kind that have 36 to 48 individual LEDs.
> However, the dispersion angle isn't as wide, and they don't seem to be as
> bright.
>
> Does anyone here have any experience with these units?

No personally, but there are a number of threads on Usenet.  Here's one:

http://groups.google.com/group/sci.engr.lighting/browse_thread/thread/ad4f81
26dd61f234/ffde892eaa0cb6c5?hl=en&lnk=st&q=MR16+LEDs#ffde892eaa0cb6c5

aka: http://tinyurl.com/3ntcqf

No seems to think highly of their light output as in: "while normal MR16
light output graphs will show the lux or fc levels at 1m (3 feet) through
20m (60 feet) or that sort of scale, some of these are measured out to just
25 centimetres, less than a foot, in some cases."

--
Bobby G.