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RLI Electric
03-05-2010, 07:58 AM
I had to do it. I was so intrigued with the LED lamps that James talks about that I got some and put them in my fixtures. I am excited to say they looked great. I installed 3000K 45 degree beam spread at 6watts and they looked exceptionally nice. Comparative to the 20watt BAB by (well whatever lamp that the fixture company provided). It was tough to buy a lamp so expensive and cutting edge but I figured that I can't sell something if I haven't tried it. I will be sure to let everyone (and James too) know of my thoughts on it. As for right now I give it a thumbs up.

sal rodriguez
03-05-2010, 09:57 AM
Here's a link that may help

http://www.lotusledlights.com/12v-led-c-3.html?zenid=cbf7875b5d7746c0f2e6b2c1eb064189

INTEGRA Bespoke Lighting
03-05-2010, 11:20 AM
Hey Sal. There are literally thousands of LED lamp re-sellers out there... Doesn't mean that their products have been designed and engineered with outdoor lighting applications in mind. I looked at the 'specifications' of a few of those lamps there; pretty lame if you delve into them.

Of course you can go around and purchase samples from all of these various sources, if that is what you are into. I have already done this, and have over 120 different LED MR16 lamps here at my shop. It was this process that convinced me to start from the bottom and re-think these things.

sal rodriguez
03-07-2010, 02:57 PM
I don't depend upon specifications from the seller to determine the use or value of a product. The way to verify is to test on one's own. To offer these things commercially and to sell blindly on un verified recommendation can be both expensive and foolish.

INTEGRA Bespoke Lighting
03-07-2010, 03:45 PM
Good Point Sal. So instead you should review the photometrics and spectra analysis data that independent labs have prepared on the LED products you purchase. IES analysis if you can find that, or pay to have this information processed yourself!

I have done this and make it freely available. It would be wonderful if more LED companies did the same thing.

Your eye might be pretty good, but it is not nearly as accurate as a calibrated spectra analysis instrument.

dglights
03-08-2010, 02:38 PM
James, quick question regarding INTEGRA LED MR16 lamp
On the spec is this the Tj for LED? Thanks

T Junction Temperature /ambient temp at 21 C / 29 Min 33 Typical 35 Max Celsius

INTEGRA Bespoke Lighting
03-08-2010, 02:54 PM
James, quick question regarding INTEGRA LED MR16 lamp
On the spec is this the Tj for LED? Thanks

T Junction Temperature /ambient temp at 21 C / 29 Min 33 Typical 35 Max Celsius

Yes Sir, you read that right.

dglights
03-08-2010, 03:41 PM
Open air or installed in fixture? Thanks again

irrig8r
03-08-2010, 11:24 PM
Sherman... I emailed you about 2 weeks ago and haven't heard back yet.... need current prices and availability... catalog if available.

Thanks.

INTEGRA Bespoke Lighting
03-09-2010, 01:00 AM
Open air or installed in fixture? Thanks again

That temp is measured while outside of the fixture. When I install it in a Cooper Lumiere 203 Bullet and operate continuous for 100 Hours we get a junction temp ranging between 44 and 48 degrees celcius. A bit warmer for sure but nowhere near the junction temps of the other lamps.

Sherman, have you ever pursued ULc or cETL listings for your line, so I can use it here in Canada?

Alan B
03-09-2010, 10:03 AM
Open air or installed in fixture? Thanks again

Exc question Sherman.

Pro-Scapes
03-09-2010, 11:04 AM
The DGlights fixture really does have an excellent output. Much nicer than I have seen in retrofits. I still have his deck light burning on my own deck and it seems to be holding color nice along side a few cast pucks with the SCB lamps.

dglights
03-09-2010, 04:20 PM
Sorry James we're still behind with the Canadian listing.

We need a way to objectively evaluate LED products whether they are integrated or retrofit. Purchasing product and waiting to see what happens is not practical or efficient. What if you wait 2 yrs to approve and when you finally purchase the LED has changed? Do you now get the new sample and wait another 2 yrs? How long do you evaluate, 2, 5, 10 yrs? If you do evaluate yourself how do you know exactly how the product is doing?

The reputable LED manufacturers are providing LM80 reports for their LEDs to help determine lumen maintenance. Drive current, LED junction temp and air temperature being determining factors. Let's say LED junction temperature is the most important.

For example you have 2 LED fixtures. Both have 50,000 hr rating. One has cooling fins the other doesn't. Both look the same when turned on. How do you compare them?

Do they use the same brand of LED? Are all LEDs the same?
One feels warmer to the touch, how much warmer? Does your hand sense the same temperature everytime?
Are they the same wattage?
Do they warm-up and cool-down exactly the same?

I propose a standard test that provides LED junction temp and can be used to compare LED products. Put the fixture on the bench, 25C 75F ambient, power it up, record junction temp for 60 minutes. LM79 is great but I've seen some data sheets that just say tested within LM79 requirements. Is the fixture at the upper or lower limit? This test will be best performed by the manufacturer of the product because you need to know the exact LED used and the thermal resistance from test point to LED junction.

With the Integra Lamp I'm reading 6Watts and the led juntion temp only rises 12C/21F. This is a very low thermal resistance. Great, now all James has to do is show how he got this info and we're able to use the LM80 report to dertermine L70.

You can't measure LED junction temp directly. We need to specify the point where the temperature reading was taken and with what type of device. We also need to know the thermal resistance from this test point to the LED junction temp. Power up, wait 60 minutes and record test point temperature. Once we have this we can calculate the LED junction temp. Now we have some hard data with proof and we can compare products.

This is in no way to bash or promote any product, but I think we really need some standards put in place. I've been using this testing method since 2005 and it's been very helpful in evaluating product and design. Mr. Baptist from Unique posted some data comparing product on another thread, we need more of this.

INTEGRA Bespoke Lighting
03-09-2010, 05:10 PM
Sherman I encourage you to look back in this forum and fully read the last five pages of "Led Landscape Lighting" These issues have been discussed and there are appropriate protocols developed and in development for the objective testing of LEDs.

An except of the thread I am referring to:

I would encourage anyone interested in learning more about LED lamp life measurements to become familiar with L70 - initiated by the Lighting Research Center (LRC) and also the "Approved Method: Measuring Lumen Maintenance of LED Light Sources - LM-80 by the IES. Soon there will be more forthcoming on the IES TM-21; a procedure in development that will outline procedures for deriving the LM-80 test data into service life rating, establishing consistency between all manufacturer data.

Here are some links to help you out:

https://www.ies.org/store/product/ap...urces-1096.cfm

http://www.lrc.rpi.edu/programs/.../...sTokyo2007.pdf

http://www.ledsmagazine.com/news/6/4/16

http://www.architecturalssl.com/cont...d=02_09_story2

As for the testing, it was appropriately done with calibrated instruments that are designed specifically photometric and spectra analysis. Measuring the junction temperatures is done with a digital thermocouple device, this is pretty standard stuff for those involved in the manufacture of LED light sources.

extlights
03-09-2010, 05:47 PM
All this disussion remindes me of why I'm sticking with non LED products...at least for now. I've looked at some and I just can't be convinced yet. We could buy some LED lamps and test them out just like everyone else, but I just don't see the point at this time. I'm sure the technology will eventually get there, but until then I'm sticking to the proven stuff.

dglights
03-09-2010, 06:43 PM
Lumiere 203 is an interesting choice since it's availabe in LED.
I know what you mean Dave, I even get sick of talking about LEDs.

I'm just trying to get through this example.
So we have a 6Watt Lamp, with maximum heatsink temperature of 35C. If installed in 203 (2.25" O.d.) the Tj for LED can go up to 48C. Is this correct?
What was the temp for test point to get 48C?
What brand of LED, I'm assuming Cree XRE?
Where is the Test point?
What's the thermal resistance from test point to LED junction?
Digital thermocouple is digital read out with what kind of attachement?

Good stuff

David Gretzmier
03-13-2010, 02:19 AM
egads, guys, I know this stuff is important to people that make LED's, but not to people who buy and use them. I could care less about heat, as we have been using 20 watt halogens and could fry an egg on a bullet.

what is important to people who buy and use the bulb is how long it will actually last under all normal outdoor extreme conditions, not 75 degrees in a lab. and by how long it lasts, I mean at what point does it drop below 80-90% of initial lumens. and when the color starts noticably going bad. That should be the hour rating, period. and the degree rating should be accurate. and you should tell us what voltage range it will work at.

I do have a question, however. In 15-20 buck flashlights, a 1 watt XRE cree R2 bin gets around 110 lumens per watt. They max out around 2.5-3 watts or 240 lumens. if you look on candelpowerforums.com, you will find that usually you can get 75-85% of the driven lumens out the front of most flashights under sphere testing. These flashlights have been out for over a year. The new GE Ultra bulbs only seem to get around 30-50 lumens per watt. the newest mr-16's I am seeing get about 35 lumens per watt. what gives? why have we went from a 90% savings in electricity to 75% ?

RLDesign
03-13-2010, 11:22 AM
Personally, I started waking up and smelling the roses after AOLP annual conference. If you would have asked me before conference, that I needed some stats to make a decision - I would have asked where can I get the stats. Due the DOE adopting LED on the national level (the whole world is), the IES and the Capliper program are now creating a standard and that is the only place you can find neutral data. Not just bench test, but fixture/field testing. Some companies reference LM80orLM79. If you choose where you measure junction temp, it can affect data. Many companies are claiming A data, but producing F data and that is why Caliper is there to help us make an informed decision. Us - the designer and the client. I know Naomi Miller from Caliper did not just go to conference to waste her time to present to 3 groups so that they would know how to log into the Caliper website for no reason. There is an accurate test that takes into consideration the fluctuations and surges that LEDs go through, but I am not sure whether switching or dimming will affect L70 or flicker. It is being tested. I know it might seem like unecessary data, but I need to know the info for LED standards and their measuring techniques. I care about warranties, but they are not put in place to fix somethihng if it breaks. The idea is that the product wont break or decrease in output is what we need to have in our pocket when we spec a fixture/lamp. I am excited that standards are becoming unified. Some contractors did not care of the hours of the halogen lamps that you purchased, but I know I sure did. I know that James and Sherman were going back on some stuff that was outside the brackets of some, but JT is an important stat.

Talk soon. Tanek - Reynolds Lighting Design

oberkc
04-02-2010, 03:01 PM
Greetings.

Confessions first...I am only starting in maintenance business and my experience in landscape lighting is limited to my own use and one other persons. I find, however, that I really enjoy fooling around with landscape lighting and don't miss a week on your forum.

I decided to enroll so that I could report that I am through my third winter with simple LED lamps into inexpensive fixtures. No failures yet (not even one). While I don't measure color temperature or lumens, I can tell you that they look as good to me as the day they were installed. Most of mine are in the soft white range (probably bit warmer than halogen) and look equivalent to about 5-10 watt incadescent.

All transformers (four total) are 50watt, controlled by insteon modules and whole house controller. Some of my wire runs are over 200 feet with no apparent loss of brightness. All connections are soldered. Total energy used is 35 watts over an equal number of fixtures. In my mind, the advantages far outweigh the disadvantages.

I post this only as an encouragement for those who are considering getting into LED. I suspect you will be eliminating a big market if you limit yourself to incadescent.

I hope at least one of you finds this useful. Belated thanks to everyone from whom I have learned much.

Tim R.
04-03-2010, 04:15 PM
I love all the technical info on the LEDs. It simply makes me realize how little I truly know about them. I agree that a equal set of bench testing standards would be beneficial for ensuring the true and equal performance tests of competing products. However, for many, simply looking good coming out of box for the first few nights is fine. They collect the check and move on. I am much more interested in the long term performance of these products since it is my name going on them once they are permenantly installed.

Keep up with the good info, I am enjoying riding the learning curve.