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Chrysalis
12-22-2008, 12:03 PM
Hey a quick question,

Are 1.5 watt LED spotlights even any where close to amount of light you would get from an mr16 30 watt halogen? What are some good comparisons? Ive been looking for information everywhere online and cant find a review anywhere! I was thinking of using the Dabmar LV-LED10 in a new landscape install. They come equipped with a mr16, 20 led, 1.5 watt, and can be seen on page 125 of:

http://www.dabmar.com/Catalogs/Dabmar%20Landscape.pdf


Thanks in advance,

Marc

JoeyD
12-22-2008, 12:24 PM
NO, NO, NO

Even the best of LED's dont compare. We supply the LUXXO LED from Kumho, and it is arguably the best LED MR16 lamp replacement module on the market. In front of our building we have one LED installed in a Pulsar on one side of a queen plam, and a standard 20w Halogen MR16 installed in another Pulsar on the other half of the palm and the halogen blows it away!! The LED's look good on the lower lying foliage and what not but on taller structures and trees LED's are WEAK! If you cover the halogen fixture up you can barely see the canopy lit and when you cover the led the halogen fills the canopy out nicely. This is on a 20ft tall queen palm which isnt a HUGE tree by any stretch.

Chrysalis
12-22-2008, 12:33 PM
NO, NO, NO

on the other half of the palm and the halogen blows it away!! The LED's look good on the lower lying foliage and what not but on taller structures and trees LED's are WEAK!

Wow Joey!

Thank you, you just made up my mind for me. I guess the technology is just not there yet for me to try to go green on lighting installs. Maybe one day they will have a price effective but powerful led lighting system on the market imagine the energy savings if people were using 2-5 watt lights instead of 30-50!

Marc

JoeyD
12-22-2008, 12:39 PM
They are getting close but LED still has aways to go.......

Merry Christmas

Joey D

TXNSLighting
12-22-2008, 01:26 PM
Wow Joey...You didnt even mention the 24v system!

JoeyD
12-22-2008, 01:54 PM
I didnt see it really applying to the topic...LOL LED and 24v dont really compare....24v is much better! LOL

TXNSLighting
12-22-2008, 02:11 PM
And there it is! Thats what i wanted! :laugh:

Chrysalis
12-22-2008, 02:16 PM
what guage wire do yall recommend for a fully loaded 600w transformer? 10, 12, or 16?

And this is the transformer we always used with my old company, no real problems other than when the hombres would accidentally overload it and the wires would get hotter than hell and the bottom would melt off. Is this one good for the price or is there somehting better out there?

http://images.google.com/imgres?imgurl=http://www.homedepot.com/catalog/productImages/400/3f/3f4bf109-bad8-4592-bbc5-5a6a1487ab0e_400.jpg&imgrefurl=http://www.homedepot.com/webapp/wcs/stores/servlet/ProductDisplay%3FstoreId%3D10051%26langId%3D-1%26catalogId%3D10053%26productId%3D100004842%26N%3D3548%2B90401%26marketID%3D401%26locStoreNum%3D81 25&usg=__Lc7dPxVM233X6dUUcaLYHWuns4E=&h=400&w=400&sz=9&hl=en&start=7&um=1&tbnid=44QR5RicfGqXlM:&tbnh=124&tbnw=124&prev=/images%3Fq%3D600%2Bwatt%2Btransformer%26um%3D1%26hl%3Den%26client%3Dfirefox-a%26rls%3Dorg.mozilla:en-US:official%26sa%3DN


Marc:)

TXNSLighting
12-22-2008, 03:46 PM
what guage wire do yall recommend for a fully loaded 600w transformer? 10, 12, or 16?

And this is the transformer we always used with my old company, no real problems other than when the hombres would accidentally overload it and the wires would get hotter than hell and the bottom would melt off. Is this one good for the price or is there somehting better out there?

http://images.google.com/imgres?imgurl=http://www.homedepot.com/catalog/productImages/400/3f/3f4bf109-bad8-4592-bbc5-5a6a1487ab0e_400.jpg&imgrefurl=http://www.homedepot.com/webapp/wcs/stores/servlet/ProductDisplay%3FstoreId%3D10051%26langId%3D-1%26catalogId%3D10053%26productId%3D100004842%26N%3D3548%2B90401%26marketID%3D401%26locStoreNum%3D81 25&usg=__Lc7dPxVM233X6dUUcaLYHWuns4E=&h=400&w=400&sz=9&hl=en&start=7&um=1&tbnid=44QR5RicfGqXlM:&tbnh=124&tbnw=124&prev=/images%3Fq%3D600%2Bwatt%2Btransformer%26um%3D1%26hl%3Den%26client%3Dfirefox-a%26rls%3Dorg.mozilla:en-US:official%26sa%3DN


Marc:)

OMG NO!!!! I really hope that is a joke. This is why there needs to be certifications so NO Yahoos can install this crap.

Chrysalis
12-22-2008, 03:50 PM
OMG NO!!!! I really hope that is a joke. This is why there needs to be certifications so NO Yahoos can install this crap.

Im asking an opinion. If you cannot reply respectfully then dont reply at all you POS.

Marc

TXNSLighting
12-22-2008, 03:54 PM
Im asking an opinion. If you cannot reply respectfully then dont reply at all you POS.

Marc

Wow...Youre out.

TXNSLighting
12-22-2008, 03:55 PM
Im asking an opinion. If you cannot reply respectfully then dont reply at all you POS.

Marc

WTF? I was replying as respectfully as i could. A professional knows not to install anything Malibu. Just stating the obvious, and i was hoping that post was a joke. Do you really think anything from home depot and lowes is quality outdoor lighting?

Thats was very disrespectful of you to call me a POS by the way. You're not going to get far in this forum like that.

Chrysalis
12-22-2008, 04:02 PM
WTF? I was replying as respectfully as i could. A professional knows not to install anything Malibu. Just stating the obvious, and i was hoping that post was a joke. Do you really think anything from home depot and lowes is quality outdoor lighting?

Thats was very disrespectful of you to call me a POS by the way. You're not going to get far in this forum like that.

Sorry but I dont particularly respond well when being referred to as a Yahoo. You could have either stated that Malibu is no good instead of being obnoxious and taking my question as a joke.

Marc

irrig8r
12-22-2008, 04:08 PM
Relax everybody.

Ryan... Be nice.

Marc... Chill out.

Not sure how much lighting you have installed, but it sounds like you might be very new at this.

I don't know any professional using less than 12 gauge wire on their home runs. The "hub" method guys use smaller gauge on the runs from the hub to the fixture (25 ft. pre-installed to the fixture usually)

Lay out your fixtures and transformer, measure your runs and add up your total wattage and do the voltage drop calculations. (I usually do this first on paper, but learn how to do it in the field too for when you make changes from your plan.)

Sometimes 12 gauge is all you need. Other times (larger load, longer distances) you might need 10 gauge. Then, when installing, double check everything with your meter.

Lots of classes are available. Good reference books too. Educate yourself on the basics.

If you don't, you might contribute to Floridians earning a reputation in lighting similar to what they already have in irrigation.... :laugh:

TXNSLighting
12-22-2008, 04:09 PM
My gosh i wasnt calling you a yahoo, i was calling your old company one. You said your old company used that...Come on now :hammerhead:

And i hoped it was a joke. Ask anyone on here about Malibu. They will all laugh and say exactly what i did.

TXNSLighting
12-22-2008, 04:11 PM
Sorry Gregg...Ha! I just like getting my point across.

Chris J
12-23-2008, 09:04 AM
The transformer capacity really has nothing to do with the guage of wire. Theoretically, you could have all 18-2 home runs if you didn't exceed the amperage limits and had very short home runs. Each size of wire has it's own limitations. 192w total load for 12/2, 288w total load for 10/2. You have to also take into consideration that the length of the home run will factor into the total wattage requirements. In other words, long home runs will create more resistance which the transformer will see as additional wattage. If you had 192w on a very long home run, the transformer might recognize the "pull" as being much higher than just the 192w of lamps so you have to compensate for that. There are many software programs available through the manufacturers that will calculate all this for you, but here's how to do it on paper:
Example:
192w of lamp load, 12/2 wire and 150' to the hub (or T).
Watts X Length of run / cable constant x 2 will give you total voltage drop:
192 X 150 =28,880
28880/7500(12/2 cable constant) = 3.85
3.85 X 2= 7.7v drop so you would need to be in a 19v tap in order to provide 12v to the hub.
Now let's go backwards with ohms law:
192w/12v =16amp (within max amperage of the wire)
16amps X 19v (the tap you are in) = 304watts
Therefore, the transformer would have a 304w draw instead of 192 in this scenario.

This is a very crude example, but I hope it sheds some light on how the length of the run and the tap will affect the load.

NightScenes
12-23-2008, 10:27 AM
FYI the Kichler 8.5 watt LED fixture is pretty much a perfect match to a 35 watt MR16. I have compared them side by side and can't see a difference. Their 4.5 watt LED is equivalent to a 20 watt MR16 and the 12.5 watt LED is just like a 50 watt MR16. I have tested each of these and they seem to be top notch.

On the other hand, I haven't seen an LED replacement lamp that has looked as good. There have also been many issues with these replacements including heat dissipation in fixtures meant for halogen MR16 fixtures.

These are just my personal observances.

JoeyD
12-23-2008, 03:04 PM
I dont understand this heat dissapation thing? The LEDS run so much cooler than MR16's. We have a bunch of LEDs running outside, all are much weaker then the halogen. But one thing I noticed the other morning when I got in before sunrise is that the Halogen fixtures were steaming with the rain hitting them and the LED's were cool as could be. The LED's run cooler therefore the brass and copper stays cooler. I see no heat dissapation isues at all. Output and color is the wink link I think. Although the Kichlers are better than most when placed side by side lighting up actual architecture and landscape you can see the difference big time. Now with all the LEDS side by side it looks ok but when mixed with halogen you can definitley tell the difference and everyone here that has looked at the lighting has noticed the difference between LED and Halogen and all say the halogen is still better in color and output.

NightScenes
12-23-2008, 04:27 PM
The heat has to do with the driver staying cool. LEDs are not nearly as hot as a halogen but they have a hard time staying cool enough (especially in brass or copper) to not damage the driver which is VERY heat sensitive.

I wouldn't mix LED and halogen on architecture either. Although the Kichler LED puts out about 2900 degrees Kelvin which is dead on for the halogen (depending on the manufacturer) there is a detectable difference in beam, color, and striations in the light. You can however mix them in the landscape or use one or the other on architecture.

JoeyD
12-23-2008, 05:17 PM
yeah, I get that part but the fixtures just seem to be running so cool I cant see how the drivers are getting too hot? I know the older LED's we played with a few years ago had issues but they ran much warmer.

If I were to mix the LED and halogen I think I would put Halogen in for all the up lighting on the walls and trees then just use the LED's for the low lying wash lights. They do great on shrubs no taller than 3-4ft.

Alan B
12-23-2008, 07:13 PM
There is a reason there are not lumen comparisons for LED -- the actual performance of each LED bulb varies depending on the fixture and heat sink that is used. Traditional bulbs put off the same lumen's, light color, and have the same life span regardless of the fixture that is used--accordingly you see published data for each bulb.

With LED's, the silicon chip does not control the power of the light-- the driver does. The driver will perform differently depending on what specific fixture it is heat sinked into.---you read that correctly--every LED will perform differently depending on the fixture. Which is precisely why there are no industry published reports on LED performance or comparisons. It's also why bulb life (40,000 hrs) and performance of LED claims should be taken with a large grain of salt. The only way to get performance is for the manufacturer to submit each specific fixture for testing.

INTEGRA Bespoke Lighting
12-23-2008, 08:26 PM
Gr1ffin. You are only sort of right. A good quality LED lamp or fixture manufacturer will be careful to order "binned" LED emitters. These have been matched by the factory and binned together so that their output is the same across the production run (bin).

As a result, you can be assured that when you order a case or two of LED Lamps from a reputable manufacturer, you will see consistancy in the light output from one lamp to another.

Regards.

INTEGRA Bespoke Lighting
12-23-2008, 08:35 PM
Joey and all:

The comparison that Joey is doing between a Luxxo LED MR16 and a 20W BAB Halogen MR16 is not entirely balanced. The LED MR16s that Joey has at the shop are 60 Degree optics (wide flood) and the BAB 20W Halogen lamp is a 40 Degree Optic (flood). As a result there will be a wider and softer (looking like less intense) output to the LED Lamp in that example.

The Luxxo 38 Degree (flood) LED MR16 lamps are currently entroute to N. America. I would suggest that you wait until you get one of these to do a proper side by side comparison.

I have installed over 1000 of the 60 deg. Luxxo LED MR16 lamps this year along with great success. They are a really nice lamp for moonlighting and uplighting foliage where you would normally use a 20W 60 Deg. Halogen or a BAB with a spread lens.

Regards.

INTEGRA Bespoke Lighting
12-23-2008, 08:48 PM
I dont understand this heat dissapation thing? The LEDS run so much cooler than MR16's

The heat has to do with the driver staying cool. LEDs are not nearly as hot as a halogen but they have a hard time staying cool enough (especially in brass or copper) to not damage the driver which is VERY heat sensitive.

Ok first of all... Paul, sorry to say, but your statement here is totally erroneous. 100% incorrect.

There is no issue whatsoever with keeping the LED driver cool. The LED drivers are solid state electronic circuits that are able to withstand the heat generated by the HB LEDs with no issue at all. The heat issue with LEDs, be it lamp modules or integrated LED fixtures, is keeping the LED emitters (the chips) cool. When a LED "chip" is subjected to heat over its rated capacity it begins to deteriorate. This happens with a breakdown in the phosphors (a 'coating' that shifts the colour to white) as well as increasing the rate at which the lumen output diminishes. This is why all HB LEDs require sophisticated thermal managment in order for them to operate to spec. You want to remove the heat generated by the LED chips from the point at which they are coupled to the board on which they are mounted.

Joey: In simple terms, don't think of comparing the heat signature of an LED lamp to a Halogen Lamp. Obviously there is a huge difference there. Think of it in these terms. HB LEDs need to operate below a specified max temperature. (usually 65 to 85 degrees celsius). Heat produced above those temperatures is toxic to the operation of the LED itself resulting in lumen maintenance issues.

If anyone has any other questions, please don't hesitate to ask.

Regards.

Chris J
12-23-2008, 11:56 PM
Joey and all:

The Luxxo 38 Degree (flood) LED MR16 lamps are currently entroute to N. America. I would suggest that you wait until you get one of these to do a proper side by side comparison.

I have installed over 1000 of the 60 deg. Luxxo LED MR16 lamps this year along with great success. They are a really nice lamp for moonlighting and uplighting foliage where you would normally use a 20W 60 Deg. Halogen or a BAB with a spread lens.

Regards.

Just curious, but since the different beam spreads aren't available yet, what have you been doing to compensate for your design? Every object, structure, foliage has a different requirment for beam spread/lumens. If you have been limited with available LED lamps, what have you been doing? Using the same beam pattern for all applications?
I'm not being sarcastic, by the way. I am simply gaining info for my extended use of LED luminaries.

Alan B
12-24-2008, 08:38 AM
[QUOTE=Gr1ffin;2657861]There is a reason there are not lumen comparisons for LED -- the actual performance of each LED bulb varies depending on the fixture and heat sink that is used. Traditional bulbs put off the same lumen's, light color, and have the same life span regardless of the fixture that is used--accordingly you see published data for each bulb.

With LED's, the silicon chip does not control the power of the light-- the driver does. The driver will perform differently depending on what specific fixture it is heat sinked into.---you read that correctly--every LED will perform differently depending on the fixture. Which is precisely why there are no industry published reports on LED performance or comparisons. It's also why bulb life (40,000 hrs) and performance of LED claims should be taken with a large grain of salt. The only way to get performance is for the manufacturer to submit each specific fixture for testing.[/QUOTe

Note--I am referring above to intergrated LED.
This is an important/interesting topic--I'm going to start a new thread specifically about LED performance and heat sinking.

Alan B
12-24-2008, 08:39 AM
There is a reason there are not lumen comparisons for LED -- the actual performance of each LED bulb varies depending on the fixture and heat sink that is used. Traditional bulbs put off the same lumen's, light color, and have the same life span regardless of the fixture that is used--accordingly you see published data for each bulb.

With LED's, the silicon chip does not control the power of the light-- the driver does. The driver will perform differently depending on what specific fixture it is heat sinked into.---you read that correctly--every LED will perform differently depending on the fixture. Which is precisely why there are no industry published reports on LED performance or comparisons. It's also why bulb life (40,000 hrs) and performance of LED claims should be taken with a large grain of salt. The only way to get performance is for the manufacturer to submit each specific fixture for testing.


Note--I am referring above to intergrated LED.
This is an important/interesting topic--I'm going to start a new thread specifically about LED performance and heat sinking.

INTEGRA Bespoke Lighting
12-26-2008, 08:50 AM
Just curious, but since the different beam spreads aren't available yet, what have you been doing to compensate for your design? Every object, structure, foliage has a different requirment for beam spread/lumens. If you have been limited with available LED lamps, what have you been doing? Using the same beam pattern for all applications?
I'm not being sarcastic, by the way. I am simply gaining info for my extended use of LED luminaries.

The majority of my outdoor lighting work is done on very large lots, in areas that are highly sensitive to issues of light pollution, light trespass, and Dark Sky Friendly Lighting. As a result, the systems I design and install are significantly different in nature than what most of you guys are doing. The overwhelming majority of my work is creating soft moonlighting effects from trees, and building mounted positions, with some under-foliage projections that take out dark shadows along paths and for view creation into the forest.

The 60 degree optic works wonders in these applications. When I was using Halogen MR16's I would always be lensing the BAB's to soften their intensity and broaden their reach.

The new 38 Degree Luxxo LED MR16 should be here soon and will open up more applications for the product.

I am also going to be working with some very cool Lumascape fixtures that allow you to focus the light beam from the lensing of the fixture. I want to see if we can emulate the characteristics of a Narrow Flood (25 deg.) to a tight spot (8 - 12 deg.) by altering the light output of the LED lamp.

Regards.

Mike M
12-26-2008, 09:58 AM
The new 38 Degree Luxxo LED MR16 should be here soon

I think this answers Chris's q, plus validates Joey's comparison. How can he compare a tighter beam halogen with an led that doesn't exit yet?

I think the point is that the availability of LED fixtures and LED bulbs is still an issue with most projects out there. I'm all gun-ho about using LED's, but every time I do a demo and start considering it during the consult, I realize I can't do the whole thing in LED, unless I start compromising the design. This gets me frustrated, and I just fall back on all halo's.

No big deal. It's not like I'm in high demand at the moment, so I think with the availability of LED fixture and bulb choices coming to market, as James indicates, is a great prospect for the very near future, so I will continue to work on positioning myself for the technology.

NightScenes
12-26-2008, 11:42 AM
My bad, I meant the "chip" and not the driver. The point I was trying to make is that heat is a relative term. It doesn't take a lot of heat to damage the chip.

Dreams To Designs
12-26-2008, 12:08 PM
James, would their be any benefit to look at an LED Maglite and how they are able to focus the beam spread from almost pinpoint to a wide, soft light? I see that as being the biggest detriment to LED lamps and/or fixtures right now is the lack of design flexibility. The color and type of illumination are different than halogen, but can create different and often better effects.

Kirk

Alan B
12-29-2008, 12:17 PM
My bad, I meant the "chip" and not the driver. The point I was trying to make is that heat is a relative term. It doesn't take a lot of heat to damage the chip.

Paul, you are not wrong by referencing the driver. You are more correct than James. James knows a lot about LED's and I commend him for educating people about them. However I respectfully disagree his statement.

The driver IS the source of heat in high output LED's, not the chip. Properly heat sinking the driver in high output LED's is the #1 issue with manufacturing high output LED's that live up to their claimed data. The second item is buying drivers that are efficient enough to run cooler (expensive).

The result of the high heat produced from the drivers does two things-- the driver efficiency drops the hotter it gets, the life span of the driver shortens, and lastly the heat from the driver can make the chip hot which in turn is not good for the chip either -- but this is an effect caused by the driver heat (not from the chip itself overheating).


Sorry to split hairs, but it is important that people understand it is the driver heat, not the chip that is the weak link in perfecting high output LED's.

For this reason, retro bulbs (poor heat sinking--and not heat sinked into the fixture) are more of a statement than solution.

NightScenes
12-29-2008, 03:08 PM
Thanks Gr1ffin for clearing that up. What I really want to get across is that although the fixture, lamp, driver, chip, etc. are much cooler than a regular halogen lamp, the heat that they DO generate damages the LED replacement lamp. This is even more pronounced in brass, copper or steel fixtures that do not dissipate heat very well.

INTEGRA Bespoke Lighting
12-29-2008, 05:08 PM
Paul, you are not wrong by referencing the driver. You are more correct than James. James knows a lot about LED's and I commend him for educating people about them. However I respectfully disagree his statement.

The driver IS the source of heat in high output LED's, not the chip. Properly heat sinking the driver in high output LED's is the #1 issue with manufacturing high output LED's that live up to their claimed data. The second item is buying drivers that are efficient enough to run cooler (expensive).

The result of the high heat produced from the drivers does two things-- the driver efficiency drops the hotter it gets, the life span of the driver shortens, and lastly the heat from the driver can make the chip hot which in turn is not good for the chip either -- but this is an effect caused by the driver heat (not from the chip itself overheating).


Sorry to split hairs, but it is important that people understand it is the driver heat, not the chip that is the weak link in perfecting high output LED's.

For this reason, retro bulbs (poor heat sinking--and not heat sinked into the fixture) are more of a statement than solution.

Sorry, but this is not the case. If it was the driver producing the damaging heat, then all of the HB LED products out there that use remote drivers would have no lumen maintenance or phosphor degrdation issues at all. The solution would be as easy as keeping the drivers away from the LED emitters. Fact is that heat dissipation is critical at the point where the LED chips (emitters, engine, call it what you want) are coupled to the boards that they are mounted to. Why? Because those HB LED chips are producing enough heat, that unless it is properly managed will damage the chip itself. The driver is simply a solid state electronic circuit that can easily handle the 60-80c. that the LEDs produce.

If thermal management of the driver was the issue, then why do ALL of the major manufacturers of LED chips go to great lengths to measure, rate, list and educate the end useres about the maximum temperature operating ranges of their products.

Do some more reading for yourself. GE Lumination, Lumileds, Seoul Semiconductors, Nichia, Cree, etc etc etc. You will quickly see what I am talking about.

INTEGRA Bespoke Lighting
12-29-2008, 05:14 PM
Thanks Gr1ffin for clearing that up. What I really want to get across is that although the fixture, lamp, driver, chip, etc. are much cooler than a regular halogen lamp, the heat that they DO generate damages the LED replacement lamp. This is even more pronounced in brass, copper or steel fixtures that do not dissipate heat very well.

Paul... Copper fixtures are excellent conductors of heat. Even better then Aluminum fixtures are. In fact Copper is almost 100% more effiecient in conducting heat than Aluminum is.

The thermal conductivity of Copper ranges from 204 to 223 Btu/(hr oF ft)
The thermal conductivity of Aluminum ranges from 118 to 144 Btu/(hr oF ft)
(Source: engineeringtoolbox.com )

Have a great day.

INTEGRA Bespoke Lighting
12-29-2008, 05:20 PM
What I really want to get across is that although the fixture, lamp, driver, chip, etc. are much cooler than a regular halogen lamp, the heat that they DO generate damages the LED replacement lamp.

Paul, you would be more correct if you said: "The heat that most LED replacement lamps create is damaging."

I maintain that the Kumho Luxxo LED MR16 lamp is the only lamp that I have tested that operates within the LED manufacturers (in this case it is Nichia) specificed operating temperature range. This is even the case when completely sealed inside of a small size fixture like the Lumiere 203 Bullet and operated continuously for extended periods of time.

How do they do this? It largely has to do with the way in which their proprietary driver conditions the power send to the LED chips. It also has to do with the design and materials used in the lamp body.

Have a great day.

INTEGRA Bespoke Lighting
12-29-2008, 11:36 PM
To further strengthen the argument that heat issues with LED lighting technology stem from the LEDs themselves and not from the drivers I direct you to this document:

http://www.lumination.com/literature/VioThermalMgmtWEB4_9_08.pdf

You will note that the GE Vio information applies only to the LED assembly as there is no "on board" driver with this product. Similar information is available from a wide variety of LED chip manufacturers.

Regards.

INTEGRA Bespoke Lighting
12-29-2008, 11:54 PM
Here is another document that deals with thermal management of LEDs:

http://www.nichia.com/specification/appli/thermal.pdf
It even has some really good illustrations to look at. :)

Again, no mention of driver based or driver induced thermal issues... Think of the driver as a necessary accessory to the LEDs... as such it can be placed remotely (such as in the stem of a path light) and thus has no bearing at all on the thermal issues of the LED light source.

Have a great day.

David Gretzmier
12-29-2008, 11:54 PM
when you look at handmade flashlights that have the newer warm white cree or SSC p4 LED's, they have a heatsink the LED emitter is glued to using thermal paste. they are trying to draw away heat from the emitter. most emitters are set to work efficiently at 3.5-4.2 volts. If the flashlight has a driver, it will boost or buck the voltage from the batteries to dim or brighten the led between the above ranges. Newer cree MCE's and P7's need different voltages at the emitter, and even in the same family, in different bins they may have different forward voltage. better or higher bins will make more lumens per watt, but may generate more heat and need a larger heatsink to not burn up.

Try to remember light is not free, it generates heat. a 20 watt halogen bulb generates light on a filament. that filament is pretty much suspended inside a glass bulb and it is pretty much suspended in a ceramic socket. all the materials tend to bleed off/insulate the heat, and even with that, have you ever picked up a bullet with a 20 or 35 in it after it has been on with your bare hands? hot stuff. The LED generates light/heat inside a very small space, not suspended at all but mounted inside the emitter. and that heat needs to go somewhere quick. thus, the heatsink. I believe it is true that LED's generate less heat than incandescant, as they use less electricity to generate the same amount of lumens or light, they just are not good at handling the heat they produce.

A driver for a landscape light has a different set of things to do- take the AC voltage and convert it to DC to eliminate the flicker from the natural 60hz frequency of 120 volts, then give you full brightness form the emitter whether you have 9 volts or 15 volts goint to the light, giving the emitter an actual 3.5-4.2 DC volts, or whatever the emitter needs to be at full eficiency. the driver can be affected by heat like anything else, but typically they make them out of heat resistant materials and should keep them away from the heatsink.

INTEGRA Bespoke Lighting
12-29-2008, 11:58 PM
Thank you David! So nice to know that there are others out there who understand this stuff! :)

Have a great day.

David Gretzmier
12-30-2008, 12:05 AM
Although I understand it, you know how I feel about these things.

I do, however, believe we can agree to disagree on what to use to make homes and landscapes beautiful with light as long as we can agree what are good and bad outdoor lighting effects. As long as the end product is beautiful lighting, and the homeowner got value for his money, then you and I will get along fine.

And You have a good day too !

dave g

Venturewest
12-30-2008, 10:53 AM
The Luxxo 38 Degree (flood) LED MR16 lamps are currently entroute to N. America. I would suggest that you wait until you get one of these to do a proper side by side comparison.

Regards.

When do you think the 38 deg will be available to ship? I have one I am ready to install right now. I can wait a few weeks to install the lamps, but I can't wait much longer than that.

Copper fixtures sound like the best option for MR16s, if I understand my own research and your confirmation in this thread. In Oklahoma we could easily have days that are 110 F. Do you still maintain that the Kumhos will not overheat in these extreme conditions.

INTEGRA Bespoke Lighting
12-30-2008, 02:14 PM
When do you think the 38 deg will be available to ship? I have one I am ready to install right now. I can wait a few weeks to install the lamps, but I can't wait much longer than that.

Copper fixtures sound like the best option for MR16s, if I understand my own research and your confirmation in this thread. In Oklahoma we could easily have days that are 110 F. Do you still maintain that the Kumhos will not overheat in these extreme conditions.

Here is what I know about the Kumho "Luxxo" 38 Deg LED MR16 Lamps:

1: Production is complete and product is supposedly on its way to N. America.
2: The optics took some time to perfect, resulted in a change of LED configuration as well.
3: The 38 Deg. lamp will come at a higher price due to the cost of the lens and the new single emitter.

Can I guarantee you that they will be available by the time you need them for your project? No, I cannot.

As far as ambient operating temperatures go: I am sure you have some days that get very hot, as do we here in Ontario. But what are your night time average temperatures like? I would suspect that things cool off quite a bit during the evening there as they do here. My understanding is that an occasional high ambient operating temperature is not going to catastrophically affect the performance of the lamps. It would be an issue if you were constantly operating the lamps at very high ambient temperatures.

Lite4
12-30-2008, 08:29 PM
James,
I have never used RGB LEDs and am unsure how you "tweek" the color of the lamps. I am also wondering if the lights can be modified to operate on the lower end of the uv band, around 350-500 nanometers as well as some of the mid and higher bands for use in indoor facilities with plantings. Can the LEDs be custom modified to achieve this type of output or would I still need to rely on some basic flourescent accent lighting for plant health?

Mike M
12-30-2008, 10:18 PM
Indoor plant health? Do you mean as in spectrum needs for growth?

The problem with LED's is the very narrow color spectrum (hence their efficiency at one particular tight wavelength and hence their low wattage).

Plants require both very high lumens as well as a wide spectrum of color. I can't imagine LED's being good plant growing lights. On the other hand, if you are looking for "cool" bulbs in close proximity that won't burn, that's different.

Even good indoor lights for growth have limitations and often need to be supplemented to cover both blooming & vegetative spectrum needs.

With RGB, you can get an exact wavelength for the color you want, but the color is just that, one very specific color, and not a spectrum.

INTEGRA Bespoke Lighting
12-31-2008, 05:05 AM
James,
I have never used RGB LEDs and am unsure how you "tweek" the color of the lamps. I am also wondering if the lights can be modified to operate on the lower end of the uv band, around 350-500 nanometers as well as some of the mid and higher bands for use in indoor facilities with plantings. Can the LEDs be custom modified to achieve this type of output or would I still need to rely on some basic flourescent accent lighting for plant health?

RGB LED lamps use DMX controllers to alter and 'tweak' their colour output. I personally don't have any RL experience in using RGB LED lamps but from what I gather the quick answer to your question is: Yes, they can be set to operate at a specific wavelength. The trick would be dialing in the controller to your needs.

If your application is specifically for use in growing plants indoors, there are a number of LED lamp products on the market that are designed specifically as "Grow Lamps". Here is some good information:

http://www.homegrownlights.com/WhyLED.html

From a quick perusal of online sites, I would say that you can find an appropriate 100% LED solution for the application.

Regards.

Mike M
12-31-2008, 08:52 AM
You would need the 100 watt LED to match a 400 watt sodium or mercury light, which is a very large unit, and listed for 600.

It's an issue of needing a larger LED fixture to get the lumens you need. They are fixed at the needed color wavelength, so you don't need a separate controller to dial it in.

That's a cool website. Take James' advice, Canadians don't have daylight for six months a year.

INTEGRA Bespoke Lighting
12-31-2008, 09:38 AM
Tim, here is some more interesting info regarding the use of LED lamps to stimulate and promote the health of plants indoors.

http://www.ledinside.com/LEDs_are_best_choice_as_grow_lights_used_in_gardening_20081229

Regards.