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wbaptist
08-06-2010, 07:38 PM
What is the common wattage LED used in landscape lighting?
What is the rule for LED wattage vs. Halogen?
Does a 1 watt LED replace a 20 watt Halogen?
What is the highest wattage LED fixture available today for outdoor lighting?

bcg
08-06-2010, 08:42 PM
4W LED = 20W Halogen
8W = 35W
12W = 50W

INTEGRA Bespoke Lighting
08-07-2010, 03:26 PM
Sorry guys but there are just way more factors involved in LED light sources that make it impossible to compare a x watt LED to a x watt Halogen. There are no hard and fast rules like those that BCG listed.

The efficiency (lumens per watt) on LED lamps and fixtures varies widely. Then you also get into correlated colour temperature comparisons. A 4000K LED will produce significantly higher lumen output per watt input than a 2700K LED.

You need to know the key specifications when choosing LED product in order to make a comparison to their incandescent counterparts.

indylights
08-07-2010, 09:20 PM
What is the common wattage LED used in landscape lighting?
What is the rule for LED wattage vs. Halogen?
Does a 1 watt LED replace a 20 watt Halogen?
What is the highest wattage LED fixture available today for outdoor lighting?

Aren't you an engineer or technical guy for a lighting manufacturer? Shouldn't you be telling us the answers to those questions? Just one more reason I have started using less and less Unique. Customer service has taken a nose dive this year.

Scott Maloney
Sunflower Landscapes

steveparrott
08-08-2010, 05:27 PM
4W LED = 20W Halogen
8W = 35W
12W = 50W

BCG's numbers are a good place to start (typical of many LED's on the market), but James is right that there are many factors involved - many LED fixtures and lamps vary from this considerably.

We should really be considering lumens (lm) per watt (efficacy). Typical incandescent MR-16's have the following lumen values: 20W (300 lm); 35W (500 lm); 50W (900 lm). These tungsten halogen sources therefor have lm/W of between 15 and 18.

LED lamps can range between 20 and 70 lm/W. Taking the highest value of both lamp types gives us a rough conclusion that LED's are about 4 times more efficient than incadescents. So, based on efficacy, you can divide incandescent wattage by 4 to achieve (a rough) equivalent LED wattage.

But this is not always the case (in fact DOE Caliper results show huge variations among manufacturers). An LED chip can be made to produce a range of lumen and efficacy values. These are primarily controlled by two factors - voltage through the chip (forward voltage) and the presence of coating (primarily phosphors) on the chip to control color.

If forward voltage is increased then both lumens and efficacy are increased. This sounds like a good thing, but higher forward voltage increases heat production. As we all know, heat management is the primary problem with high brightness LED's - especially in landscape lighting applications. So, be very suspicious of very high brightness LED lamps - they may fail prematurely in an enclosed fixture.

The second factor that affects lumens and efficacy is the presence of the phosphor coating. LED's without any coating produce light in very narrow frequency peaks and are perceived as very poor sources of illumination (low correlated color temperature(CCT)). To spread out these peaks and better achieve something closer to incandescent light, mfgs apply a phosphor coating to the chip. The coating greatly improves color but it also decreases lumens and efficacy. So, be very suspicious of very high brightness LED lamps - they may have very poor color quality.

emby
08-09-2010, 01:24 AM
Great information everybody. Thanks.

Ken

wbaptist
08-09-2010, 12:57 PM
What is the common wattage LED used in landscape lighting?
What is the rule for LED wattage vs. Halogen?
Does a 1 watt LED replace a 20 watt Halogen?
What is the highest wattage LED fixture available today for outdoor lighting?

Let me clarify. I am looking for input from the field.

What is the common wattage LED used in landscape lighting? Is it a 4 watt mr16 drop in, 12.4 watt integrated unit or a 2 watt bipin. I just want to see what people are using.
What is the rule for LED wattage vs. Halogen? What do guys use in the field? If they have a fixture with a 20 watt halogen lamp do they use a 4 watt led or a 12.4 watt led?
Does a 1 watt LED replace a 20 watt Halogen? This question is asked to us all the time. "doesn't a 1 watt LED produce us much light as a 20 watt halogen". I asked this question to see if this is the belief in the field.
What is the highest wattage LED fixture available today for outdoor lighting? I really don't know this answer.

Tomwilllight
08-09-2010, 03:09 PM
Steve Parrot says above "in fact DOE Caliper results show huge variations among manufacturers" and he is absolutely correct.

Caliper shows major performance variations among LEDs. Over time, most LEDs available now will change color and lumen output in difficult to predict ways. AND 25% of the LEDs tested didn't even last 1000 hours.

Please allow me a longer quote from the report Steve referenced.

"Due to the range of behaviors and rapid rate of change of SSL technology, buyers and specifiers should be wary of all product life claims. More than half the SSL products subjected to CALiPER long-term testing will not provide 70% of initial light output at 50,000 hours and already exhibit significant color shift within the duration of the CALiPER long-term operation. About one quarter of the SSL products would not pass a simple 1000-hour operational test: they do not last as long as a traditional incandescent lamp. On the other extreme, a few products show negligible lumen depreciation after more than 12,000 hours of operation — demonstrating that at least in some cases, the potential for very long SSL product life appears to be achievable."

Find & read it yourself @ <http://apps1.eere.energy.gov/buildings/publications/pdfs/ssl/caliper_round-10_summary.pdf>

Frankly, with changing lumen output, color shifting and greatly variable lives, I don't think it's possible to answer the questions you ask at this time. The technology is changing so quickly it is difficult to make comparisons.

The good news is that the report acknowledges that some LED product IS performing very well after 12,000 hours of continuous operation. That is a long time... About the life of HID and under-voltaged MR16 lamps....

My suggestion is that you obtain (invest in) sample LED replacement lamps and Luminaires with dedicated LED's and decide for yourself what works for you. The most useful time I've spend in the last few years was my trip to Las Vegas to LightFair last May. I looked, I invested in samples and I've learned.

Now I've got them hanging in my garden... and I'm watching.

Tom

steveparrott
08-09-2010, 03:54 PM
I concur with Tom's remarks.

Let me clarify. I am looking for input from the field.

Why would you want input from the field? The field is populated with all sorts of LED's from many manufacturers whose claims are suspect. I hear all the time that homeowners insist on LED's for their landscape lighting. Installers comply and install whatever fits and whatever a salesman has recommended. They don't know how the lamps will function one or two years down the road - no one does.

Having said that, there are some promising entrants and within this next year we should start seeing which units hold up and deliver.

wbaptist
08-09-2010, 04:31 PM
I concur with Tom's remarks.



Why would you want input from the field? The field is populated with all sorts of LED's from many manufacturers whose claims are suspect. I hear all the time that homeowners insist on LED's for their landscape lighting. Installers comply and install whatever fits and whatever a salesman has recommended. They don't know how the lamps will function one or two years down the road - no one does.

Having said that, there are some promising entrants and within this next year we should start seeing which units hold up and deliver.

I just want to know what people are using. I don't care about the manufacturer. I just want to see what is being used. Is a 4 watt, 6 watt, 8 watt, 10 watt or 12 watt the most commonly used bulb?

Tomwilllight
08-09-2010, 05:22 PM
I just want to know what people are using. I don't care about the manufacturer. I just want to see what is being used. Is a 4 watt, 6 watt, 8 watt, 10 watt or 12 watt the most commonly used bulb?

wbaptist,

The point is that there are no standards... they do not yet exist as far as I know... the LED lighting industry is largely the Wild West where anything goes. There are shoot outs on every corner and we all are waiting to find out who's going to win.

Will the Earp brothers "corral" the McLaury brothers' gang. Will Tombstone know peace?

It will happen... it is happening... but there are still a lot of cowboys out there only interested in simple answers to difficult questions and a quick profit.

What is the WATTAGE of a manufacturer's LED lamp, generally, has less to do with the lamps performance than WHAT GENERATION is the lamp. The more recent the generation the more likely the lamp will perform better than the last generation by the same manufacturer.

Just a few years after Edison invented the electric lamp, there were dozens of manufacturers of electric lamps. Today, how many are there? Not many. And how good are our incandescent, HID and florescent lamps? Excellent. The same will eventually happen to the LED.

Tom

BTW, an LED is not a bulb. It's a CHIP. :):):)

David Gretzmier
08-10-2010, 12:20 AM
I agree with Tom and others, asking for common wattage is the wrong question, unless you are checking the lumens per watt figure.

cree is probably the most common LED manu out there, and the xpg is thier newest LED chip. the light output of that "bulb" can be similar to the light output of a 5 watt, 10, 15, 20 , even nearly a 35 watt halogen bulb by virtue of how many milli- amps the LED is operating at . many flashlights have this LED and have 4-5 different brightness levels from dim ( 5-20 lumens ) all the way to maxing it out ( 1500 milliamps takes you close to 500 lumens ) . and in the white color xpg's, color temperature on that LED comes in 4 different flavors, and each flavor has different "bins" for different efficiencies, etc.

3 years ago if you had asked what wattage an LED was, you could safely say that a particular common Luxeon LED was a 1 watt, 3 watt or 5 watt LED. further, Ostar made some 6 die and up leds that got up into 15 and 25 watt leds. but the last 16-20 months have brought several single LED's that can have output that scales to mimic the output of a 1, 3, or 5 watt LED.

you gotta love the Caliper results. what product on earth could have a failure rate of 25% and still be in demand by homeowners ? The tests I have done with LED's are far more dramatic- nearly every mr-16 LED I have tried over the last 6 years has failed. only a of few the ones tried in the last 6 months are still working ( reccomended by James and others). to be fair, they look better and last longer than the others, but the failure rate on Christmas light LED's over the last 6 years are the same. spectacular failure.

as a bonus, you get to pay a premium of 500-1500 percent more for bulbs and watch them fail quicker than halogen.

wbaptist
08-10-2010, 12:56 AM
I agree with everything you guys are saying. The point of my question was to expose how many people still dont have any LED knowledge. We field LED calls all the time and everyone still talks about wattage. The homeowner simply does the math on the wattage savings. The homeowner and the average contractor do not have the facts or know the right questions to ask. I was trying to get an idea of what was being used. I understand what should be used and how it should be used and why it should be used.

Sorry for this thread going the wrong direction. But its full of good info.

Thanks,
Rusty Baptist
rusty.baptist@uniquelighting.com