@BIGE yes happy anniversary brother
That’s probably going to work okay passive, but if your COBs get too hot, you can buy little CPU fans from Electronic Goldmine dirt cheap. Finned heat sinks work better if the fins are oriented vertically, so it helps to blow some air down the fins when the have to be horizontal.
We were a little skeptical as well, but he has already built a light using them with same cobs in different cct a while back. Seems to have worked out very well.
That is quite a lot of aluminum between the heat sinks.
@skgrower how many watts maxed out are thos monster diodes you got … I like that idea better then the strips almost … you can condense more light in a smaller package in my head … or do you need alot more heat sink and space between diodes of that size…if you dont mind how much are those heads apiece $
A lot of growers still prefer cobs over any of the midpower offerings. They definitely require more heatsink because the thermal load is more condensed. Cob spacing usually depends on which cons and what power level you’re running them.
So those are individual cobs , ok cool do you feels the cobs or eb strips deliver the light more efficiently… if you were starting scratch would you go cob or strips
Both, depending on situation. As general rule of thumb, the strips and boards are usually more efficient. But it would depend on exactly which cob and which strip and the power level of each.
I’m leaning tword 1050 ma… is the life of the diodes comprimised running them full tilt… or do you just need sufficient sinks to maintain the heat capacity at 1400ma either way I know your unmols drop a little at maxed out …when you say running efficiently do you mean most lumens for least amount of power before it curves back? And if I’m not worried about efficiency as much as more light … if I’m trying to pump as much light as possible say I have 5 eb 1120s with dim … what would you rent them at to get the absolute most out of your plants I’m not worried about power consumption, or life of the light I want the plants to get maximum out of the light… I would think running it max power will give me most for plant right?..
Point me to the highest output setting for those 5 strips
Well 1400ma is max for eb gen2. The 3500k is like 175 lumens per watt at 700ma at 25c junction temp. At 1400ma you’d probably expect them to run about 158 lumens per watt at 25c. In either case it’s unlikely you’ll make the 25c tj. But it will be lower at 700ma than 1050 or 1400ma. So higher you go temp correction will be greater. It’s pretty linear at no correction at 25c and about 10% correction at 85c. Get into that 85c range and that’s where your led life will drop.
I have never recommended anyone run them over 1050ma. Not because you can’t, because I’m trying to help people get good lights. A light that runs at 165 lumens per watt is superior to a light that runs at 150 lumens per watt, even though it may have a little lower light output. That being said, the hlg-240h-c1050a will run 5 1120 eb gen2 nicely there. But the 1400ma driver won’t.
To go back to your original question, bridgelux vero 29b or c will both be more efficient than strips at that power level. If you can maintain temps, the 29c is 165 lumens per watt at almost 120 watts.
One last thing the EB gen 2 1120s @1400 would be about 41 watts and @700 there 27.3,so at the 158 lumens per watt I will have way greater lumen output @ 41x158 =6478 lumens per strip opposed to the 175x27.3= 4777.5 lumens per strip I know umol/j will drop since the efficiency drops but wouldnt the more lumens comming from the same strip be more beneficial to the plant regardless of the life of the led… say I ran at 1400 would I need a plate type sink since I will producing much more heat… but back to that how much life are we REALLY degrading running at that power since LEDs have 50,000 hour life I’m just not getting why more lumens is not better when disregarding the efficiency
The photon efficacy is going to drop probably about in line with the luminous efficacy. That 158 is only true if you can maintain tj of 25c. You won’t, I promise. If you’re alright with giving up something like 15% efficacy then your statement would be true. There is more light running at 1400ma than 700ma. But it’s a lot less light per watt. You’re trading efficiency for output is all. You can hit same light output by adding more strips at lower current.
And beyond a certain point you don’t really gain anything as far as the plant is concerned. Unless more elaborate setups like enclosed CO2 with a hydro system or something like.
Also very good point. If you’re running anywhere around 2.5 umol per joule there’s not really any reason to be above 30 watts per square foot. When you see the guys killing it with even less than that, it’s because they built that high amount of light per watt into their lights.
Here’s the finished product already at work. I’m running it at 350 watts or 85%. It runs cool enough for passive, but I’m running 2 20w clip on fans
I know that I don’t want to build em for money. It took me about 16 hours to build.