L.E.D. vs HALIDE/T5/VHO

[superduperwesman]

I say we design LEDs that are easy to replace and make a killing

[OceanicCorals-Eugene-]

Originally Posted by sphelps

The other day you seemed to agree that 10 years wasn't reasonable, what's changed??

Perhaps changing a ballast is as easy as changing a driver, that's fair enough, but how many drivers are used to drive 250W of LED compared to the number of ballasts for 500W of halide?
How is changing an LED as easy as changing a Halide or T5 bulb? Even the shear number of LEDs to replace in comparison, it wouldn't take much longer to start over. Sorry but if you have to break out a soldering iron it's not that easy. Plus I'd like to talk about actual fixtures not DIY approaches. Like I said let's stay in the real world.

My assumptions were very little, you're assuming way more including price drop when more realistically the LEDs you need to replace down the road will be extinct and difficult to source. You'll have to adapt new types of LEDs into the fixture which will add more complication. Maybe perhaps someone could provide a manual from a supplier of an LED fixture that shows the user how to replace the LEDs? I imagine such thing doesn't exist, for obvious reason.

I think it all comes down to the design of any commercial fixture on how easy it is going to fix. Having quick disconnects on parts would allow the plug and play feature you see in most MH systems now. I still remember before when a MH system had multiple components to it before it would work properly. The same would apply here. until a set standard comes out for LED units and connections we are going to see a ton of ways to do it until a "user friendly" way is discovered. We are already seeing this in some of the fixtures coming out, Ron had mentioned the Maxspect fixtures using quick disconnects for there individual emitters (no soldering there). AI has 3 emitter modules (not as efficient but easy to change out)

Regarding the assumption of LED bulb prices droping is not all that off. LED lighting is moving at an incredibly fast pace. In 2000 the cost of a 5mm high intensity white/blue LED would cost $2.00 each from manufactures and now they cost a few cents. No doubt will the same thing happen with high power 3W + LEDs , look at when the luxeons first came out we were looking at manufacture cost of $10 and look at where is it now. LEDs are unique that they are current driven, so even if the specs on newer LEDs change it would be the total forward V and the amount of current taken thats not going to effect the way you pair up LEDs to drivers and should only take a few minutes to figure out how many LEDs can be in an array from simple math.

Originally Posted by superduperwesman

I say we design LEDs that are easy to replace and make a killing

Watch someone is going to put a patent on quick disconnects now that we've mentioned it for LED purposes.

[Ron99]

Originally Posted by superduperwesman

I say we design LEDs that are easy to replace and make a killing

Already being done the Maxspect fixtures are nicely designed in that sense. The individual LED stars are fixed to the heatsink by a couple of screws and the electrical connections are by connectors like computer fans. So to replace them you unscrew the screws, disconnect the wire. screw down the new emitter and reconnect the wiring. A couple of minutes and one screwdriver is probably all you need. Also Bridgelux is developing an interchangeable LED module geared towards home lighting etc. but it could probably be used for aquariums too if it works out.

Originally Posted by sphelps

The other day you seemed to agree that 10 years wasn't reasonable, what's changed??

Perhaps changing a ballast is as easy as changing a driver, that's fair enough, but how many drivers are used to drive 250W of LED compared to the number of ballasts for 500W of halide?
How is changing an LED as easy as changing a Halide or T5 bulb? Even the shear number of LEDs to replace in comparison, it wouldn't take much longer to start over. Sorry but if you have to break out a soldering iron it's not that easy. Plus I'd like to talk about actual fixtures not DIY approaches. Like I said let's stay in the real world.

My assumptions were very little, you're assuming way more including price drop when more realistically the LEDs you need to replace down the road will be extinct and difficult to source. You'll have to adapt new types of LEDs into the fixture which will add more complication. Maybe perhaps someone could provide a manual from a supplier of an LED fixture that shows the user how to replace the LEDs? I imagine such thing doesn't exist, for obvious reason.

I never said that 10 years wasn't reasonable but rather than argue the point I conceded at least 6 years for our modeling of scenarios. Only time will tell what the real lifespan is but given what is known with 40 years of LEDs existence, 10 years is quite possible.

If you keep the junction temperature below 80 degrees C you will have 30% decrease over 50,000 hours. Keeping those temperatures is not hard. The OC spotlights run with heatsinks below 50 degrees and my heatsink is barely warm to the touch (I will try to get accurate temperature readings later). So if we assume degradation is linear then I will have 20% decrease in output/PAR/PUR after 33,333 hours. That is just over 9 years with 10 hours per day of use. Adjust that accordingly depending on your lighting schedule. Light for 8 hours per day and you could see over 11 years with only a 20% decrease. At 12 hours that is over 7.5 years. But if you want to call it 6 years we can do that for now. Let's talk again in six years when I can do some PAR measurements on my fixture

As for changing the LEDs it is all down to the design. See my comments above regarding the MAXspect fixtures. As Eugene mentions, the AI units have 3 emitter modules that are easy to change out and shouldn't break the bank. Here's a teardown of the AI so you can see it:

http://reefbuilders.com/2010/03/31/i...aillumination/

And here's something on the Maxspects where you can see one image of how their LEDs are hooked up:

http://reefbuilders.com/2010/01/22/m...ium-led-light/

Both the above would require the use of a screwdriver to replace the LEDs. Real world enough for you Is it more work then replacing a bulb? Maybe a little but not by much. And using a soldering iron to swap wiring is really not that difficult. If you don't want to deal with that I am sure a repair shop could do it for you fairly inexpensively.

With regards to drivers, they should use multiple drivers. Mine has 8 separate drivers. One failing means replacing one driver at $30 rather than a single ballast at $60 to $150 depending on what type of ballast is used.

[sphelps]

That's good news about fixtures already having ways to easily replace the LEDs, I didn't know they where being made like that yet. Sounds like the MAX fixture is going to be somewhat more economical than the AI as it sounds like it takes a more universal LED replacement where as the AI requires replacement sets that can only be purchased from the manufacture. Ideally a standard should be introduced to all these fixtures for an easy screw in replacement or something so various lighting companies can make replacement LEDs just like metal halide and T5 bulbs.

Basically it seems now my only real concerns are reliability and lifespan. I have extreme doubts that these things will do more than half what they are rated for but I guess time will tell, it's just an awfully long time to wait. I would definitely consider a LED fixture if

• The LEDs could be easily replaced with a somewhat universal LED design (open up competition in the future)
• The fixture was visually appealing (something like the giesemann fixtures)
• Made from quality material like aluminum and did not require fans
• Remote drivers making the fixture light enough to be hung easily from two single points
• Controllable by 0-10V interface
• Minimum 3 year warranty

With all that I would expect to pay between $2000-$3000 and would be happy to do so.

[StirCrazy]

cool, I go away for 3 days and stuff been flying.

the problem is like any other lighting there re going to be good ones and bad ones. good ones will run for 50000 hours with out a problem as they have done there home work and designed a system that runs under 80 C , exotic ones may last longer as they will have super cooled systems that run under 40 or 30C which in all likly hood will give a longer life span as it is basicly heat that is the determanaing factor for the life and intensity drop in LED, they are not effected by water, salt, vibration, ect.. unless the water, salt, ect affects the contact between the heat sink and die, but then heat will go up. but yes there will be the junky brands out there that will last under 6 years.

as for the PAR shift in MH bulbs, there is most definatly a shift and it can be large or it can be small. depends on the bulb its self and the ballast you are driving with. a 10000K bulb will generaly have a lot smaller of a shift than a 20000K bulb, but the that in its self realy means nothing. I have measured a 20000K bulb with a 40% reduction in PAR at 14 months with only a 32% reduction in LUX, so right there it is telling you there is much more than just the intensity lowering the PAR value as if that were the case the PAR and lux values would decrease at the same rate. I have had some 10K bulbs where the LUX decreased faster than the PAR and some the otherway. (an theres were all on the same ballast) so it realy depends on the initial make up and quality of the bulb including which halides and the ratios they use to make there color spectrum, as there are hundereds of different combanations that will give you any givin color.

so back to LED you want to look at longjevity, we can all agree the solaris is a lower end LED fixture, but asside for the odd problems they are going on is it 5th year now (they first came out in 2005 I believe?) with only ballast replacments (the ballasts were garbage ) and the odd LED replacment which is in all likely hood a result of the ballast failing.

Oh and for the record, T5 are infieror to MH

Steve

[StirCrazy]

Originally Posted by sphelps

I would definitely consider a LED fixture if

• The LEDs could be easily replaced with a somewhat universal LED design (open up competition in the future).

thats going to be hard as die's are propritary, but all that being said I guess you could solder any LED to almost any die so who knows.. the easy answer would be to design a holder for the die that attaches to the heat sink. at any rate I understand this one as it is easy on any fixture if you know ho to use a solder gun right now but if you don't..

• Originally Posted by sphelps

  The fixture was visually appealing (something like the giesemann fixtures).

like any other lighting I can see nice ones and ugly retro kits.. you have the ability to have a more sleak looking fixture with these maybe two inches thick

• Originally Posted by sphelps

  Made from quality material like aluminum and did not require fans.

I think they will all still require fans, at least the high end ones, but the difference will be in the size of the fans. a realy good heat sink design will have small almost totaly silent fans that just insure air movment over the fins, where cheaper designed units will have larger fanse and depend on bulk air movment ro remove heat.

• Originally Posted by sphelps

  Remote drivers making the fixture light enough to be hung easily from two single points.

already being done.

• Originally Posted by sphelps

  Controllable by 0-10V interface.

same here, it all depends on the company designer and which ballast he picks. I think some will have intagraded controlers also so they are independant from your other equipment.

• Originally Posted by sphelps

  Minimum 3 year warranty

Originally Posted by sphelps

With all that I would expect to pay between $2000-$3000 and would be happy to do so.

hmm.. If I was making a high end product like this I may concider this but 3 years, as a bumper to bumper wouln't make sence.. how about something like 1 year on ballast wiring, electronics, 4 year on LEDs ?

Steve

[sphelps]

Steve, the fact that you measured a 40% drop in par and 32% drop in LUX would suggest the two are directly related. The difference of 8% is minor considering the likely test conditions and equipment used . Anyways the point I was making as a shift in CCT (not PAR) does not necessarily mean your par has dropped, depending on the bulb and ballast it could mean an increase or a decrease in PAR meaning the two are not directly related. A decrease in PAR is simply a result of an overall decrease in intensity which could be measured in LUX. The argument was that LEDs last longer than halides because they don't suffer the CCT shift meaning a more stable PAR reading over time, I suggested this isn't the case.

Producing a standard LED replacement for fixtures is no different than any other lighting type, they've already adapted LEDs to fit into almost all standard residential applications. This is no different, first the standard is introduced and then manufacturers build fixtures to accommodate them.

Retro kits are different than fixtures but yes there are good looking and bad looking fixtures for almost everything. Currently the LED fixtures I've seen are more in the cheaper plastic look like cheaper halide and T5 fixtures, nothing really high end yet with the exception of a few module based fixtures such as the AI but the module design itself isn't visually appealing IMO. Realistically this is a very small constraint and can be easily overcome.

Most dimable or controllable lighting fixtures are based on a standard 0-10V system. While not everyone would require the ability to externally control their light fixture it should certainly be an option. One would think with the current patent on LED fixtures with built in controllers having a 0-10V plug in for an external controller would be a good thing.

Proper design of a heat sink could maximize the inductive heat transfer eliminating the need for fans. Fans are needed in the current fixtures because the heat sinks are simply standard units not designed specifically for LEDs and therefore requiring addition convective cooling. Designing the heat sink to concentrate additional surface area at the LED locations would be the first step. There are also different grades of aluminum or other materials which offer higher inductive properties than what is probably being used. Fans simply cut the cost of the heat sink dramatically which is why they are used. Eliminating the fans would actually increase quality and reliability since fans often fail or become restricted over time which could result on over heating. Also using fans will result in an uneven heat distribution meaning some LEDs will run warmer than others. These two problems could explain why fixtures have suffered from LED failure, I can't imagine any fan lasting for 10 years over a SW aquarium. Eliminating the need for fans would definitely increase reliability.

Perhaps the warranty isn't as big of an issue. Most other fixtures and equipment we use is usually limited at 1 year as well. The difference with these LED fixtures is they are new and marketed as something that will last 10 years and save you money in the long run. Manufacturers could back up these claims by offering better warranty and with a higher end fixture I would expect it to be that way but perhaps such a fixture doesn't exist yet. I wouldn't expect the warranty to cover every component but if I look at my RD pump it was marketed as an efficient quality pump designed to last longer and therefore actually save you money in the long run. It comes with a lifetime warranty on the bearings. I've had bearings fail on other pumps and while it's not the only component that can fail it still says the manufacturer is standing behind there claims and product.

[OceanicCorals-Eugene-]

Originally Posted by sphelps

Proper design of a heat sink could maximize the inductive heat transfer eliminating the need for fans. Fans are needed in the current fixtures because the heat sinks are simply standard units not designed specifically for LEDs and therefore requiring addition convective cooling. Designing the heat sink to concentrate additional surface area at the LED locations would be the first step. There are also different grades of aluminum or other materials which offer higher inductive properties than what is probably being used. Fans simply cut the cost of the heat sink dramatically which is why they are used. Eliminating the fans would actually increase quality and reliability since fans often fail or become restricted over time which could result on over heating. Also using fans will result in an uneven heat distribution meaning some LEDs will run warmer than others. These two problems could explain why fixtures have suffered from LED failure, I can't imagine any fan lasting for 10 years over a SW aquarium. Eliminating the need for fans would definitely increase reliability.

If you look closely at well designed heatsinks they all incorporate fans to dissipate the heat and thats because most components work better at lower temperatures. One of the things that you see heatsinks on mostly are computer parts, there are heatsinks that are "silent" and require no fan but run the processor at 10-20C higher than the same heatsink with fans. The design of the heatsink itself is definitely going to help with the heat dispersion but if these units are run without a fan you/we can all expect them to never meet the 50,000hr that the manufactures claim. The main reason is heat, the lower the heat you can keep on the LEDs the more efficient they run, and the slower the intensity drop on the LEDs as well. If you want to see an example, wire some 5mm leds and put them in isolated environments of room temp, 50C, 80C you will no doubt see the 80C intensity drop along with a major color shift as well.

If manufactures actually source out reliable fans for there fixtures, like those found into computer cases, low RPM high CFM fans the units will be near silent yet still provide the cooling needed for the LEDs. Some companies will still try to build fanless LED fixtures, elos is one that comes to mind, but they dont drive the LEDs to its full capacity in those fixtures. But again it all comes down to what the company wants to do with the units, so i think what needs to be understood is how to channel the air flow inside the fixture itself to provide efficient cooling so that all emitters get cooling thats somewhat the same.

[Ron99]

I think it is not only heatsink design but the overall fixture design as well. Convection cooling can work if the heatsink is open to the air and visible. if you want to enclose it in a housing then you need fans to help move air. And even if open to the air fans will help keep the LEDs cooler than convection cooling alone.

My fixture is enclosed in a housing and I am running 3 low RPM computer fans. I cannot hear the fans at all (well maybe if I put my ear right next to them) and my heatsink is very cool. So I expect very long life out of my array with no noise. The fans should last as they are low rpm thus putting low stress on the bearings and are on top of a closed housing. Unless the location of your aquarium is excessively humid or you frequently splash water up and over your light fixtures I don't see fan reliability being a huge problem.

If you look at the Solaris fixtures that suffered LED failures it was not likely due to the fans but to the fact that there were no real heatsinks to help draw heat away. The heatsink setup of the Solaris units was completely inadequate and I do not think it is representative of what should and could be done with LEDs.

[StirCrazy]

Originally Posted by sphelps

Steve, the fact that you measured a 40% drop in par and 32% drop in LUX would suggest the two are directly related. The difference of 8% is minor considering the likely test conditions and equipment used .

A decrease in PAR is simply a result of an overall decrease in intensity which could be measured in LUX. The argument was that LEDs last longer than halides because they don't suffer the CCT shift meaning a more stable PAR reading over time, I suggested this isn't the case.

wohwoh man, I never said they wern't related only not the only factor. the simmple fact is if the big blue spike shifts to the left, PAR will drip off as it shifts compound this with a decrease in intensity and it will be compounded.

you can not gage PAR out put with LUX, two totaly diferant and unrelated measurments. you are in one case measuring the amount of the emitted light with in a specific wave length, in the other you are measuring the amount of visiable light that falls on a given area. kind of a mass vs PSI but of different componants. Like I said in the previous post, no two MH or T5, ect age identicaly. this is due to various factors, including gas concentrations/types inside and so on. LED eliminates this by using a solid state chip encapsulated with no air/gas/ect surounding the chip, but they do have a problem as mentioned... heat. if they are allowed to warm up they will go through a reduction in PPF, which rises again once cooled. this can be as much as a 30% reduction in as little as 1/2 an hour with out any cooling and no drop in intensity. so using a heat sink and fans properly is a twofold benifit.. maintains the PPF output and the life on the LED. I think you would need the fans personaly, other wise the fixtures would be huge inorder to give each LED enough heatsink to make passive cooling possible. by having fans and preperly using them you will be able to produce lighter, more sleak fixtures. for what it is worth I had 4 computer fans running over my sump for 8 years starting and stopping 4 times a day. although they were coated with salt spray they still worked..

Steve