MR16 LEDs for Landscape Lights

["Jeff Volp" <JeffVolp@xxxxxxx>]

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?

Jeff