MR16 LEDs for Landscape Lights
Bookmark this page:
 Yahoo!
 Google
 Windows Live
 del.icio.us
 digg
 Netscape
|
|
||||||||||||||||||||||||||||||||||||||||||||||
|
Posted by Jeff Volp on June 22, 2008, 11:27 pm
Please log in for more thread options 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 | ||||||||||||||||||||||||||||||||||||||||||||||
|
Posted by Robert Green on June 23, 2008, 2:04 pm
Please log in for more thread options > 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
pretty
> 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 > much sealed except for a drain hole, conduction cooling for the higher
lamp.
> 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 > 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. | ||||||||||||||||||||||||||||||||||||||||||||||
|
Posted by Jeff Volp on June 23, 2008, 5:08 pm
Please log in for more thread options >
>> 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." Yes, I did my share of Googling. I read that one, and another that claimed the photons didn't have enough pressure behind them because of the low wattage, so they slowed down. OK... These seem to be getting better all the time. I'm going to pick up several different samples to see how well they compare with the halogens for landscape lighting. Jeff | ||||||||||||||||||||||||||||||||||||||||||||||
|
Posted by Robert Green on June 24, 2008, 4:10 pm
Please log in for more thread options
(crossposted from comp.home.automation) > >> Does anyone here have any experience with these units?
> >
http://groups.google.com/group/sci.engr.lighting/browse_thread/thread/ad4f81 > > No personally, but there are a number of threads on Usenet. Here's one: > > > > > > 26dd61f234/ffde892eaa0cb6c5?hl=en&lnk=st&q=MR16+LEDs#ffde892eaa0cb6c5
through
> > > > 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) > > 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." >
claimed
> Yes, I did my share of Googling. I read that one, and another that > the photons didn't have enough pressure behind them because of the low
> wattage, so they slowed down. OK... Yes - there was some levity in that thread. I assume that gentlemen was trying to explain the difference between nearly point sources of light like LEDs versus much larger sources. Photometry is more than a little confusing because there are so many ways to measure it: talbots, candelas, nits, lumens, foot-lamberts, foot-candles, etc. Did you post in the lighting newsgroup? I looked but I didn't see anything so I crossposted this for you. (-: > These seem to be getting better all the time. I'm going to pick up
several
> different samples to see how well they compare with the halogens for
> landscape lighting. That would have been my next suggestion. From what I am reading, they've got a ways to go but for landscaping their "short throw" might not be such a liability. In your 120F degree end of the world, I'd also want to do some serious testing, like what happens if a bulb ends up running accidentally when it's full summer daylight shining on them for 8 hours at well over 100F. -- Bobby G. | ||||||||||||||||||||||||||||||||||||||||||||||
|
Posted by Jeff Volp on June 24, 2008, 8:02 pm
Please log in for more thread options
>> These seem to be getting better all the time. I'm going to pick up
>> several different samples to see how well they compare with the >> halogens for landscape lighting. > That would have been my next suggestion. From what I am reading, they've
> got a ways to go but for landscaping their "short throw" might not be such > a > liability. In your 120F degree end of the world, I'd also want to do some > serious testing, like what happens if a bulb ends up running accidentally > when it's full summer daylight shining on them for 8 hours at well over > 100F. That's a good point. It would probably cause rapid deterioration, and it is something I will have to protect against. Since they are under X10 control, it is easy to have the Ocelot watch for a daytime ON, and just switch them back OFF after a few seconds - leaving them on just long enough for testing. Jeff | ||||||||||||||||||||||||||||||||||||||||||||||
| Similar Threads | Posted |
| MR16 LEDs for Landscape Lights | June 22, 2008, 11:27 pm |
| Halogen Bulbs mr16 | November 19, 2005, 7:14 pm |
| Halogen Bulbs mr16 | November 19, 2005, 7:17 pm |
| Automated lawnmower using rate gyro, RS485 and Infrared leds | December 25, 2007, 1:38 pm |
| Landscape Lighting Controller | November 8, 2005, 5:09 pm |
| LED's for landscape (cont) | July 7, 2008, 12:07 pm |
| X10 and LED lights | December 4, 2005, 4:48 pm |
| Lights flickering | August 30, 2005, 5:41 pm |
| Keeping lights off at night | March 3, 2005, 11:49 pm |
| LED Lights and other automation protocols | April 5, 2005, 8:13 pm |
| Re: X10 with Compact Fluorescent Lights (fwd) | July 13, 2005, 12:10 am |
| caution is needed with lights! | December 8, 2005, 2:02 pm |
| dimmer lights for house | February 12, 2006, 7:10 am |
| Controling Holiday Lights | October 15, 2006, 9:37 pm |
| Random X10 all lights on/all units off over and over | December 9, 2006, 12:05 am |
> the 20W halogens in our landscape lights with MR16 LEDs. While the LEDs