Quantboard heatsink alternatives

[kang]

Hey guys,

I'm new to this forum and have been looking into quantum boards for a while now. I share two grow spaces in my cousin's home wich are both 1,20m x 0,50m. The height is 1.80m for both aswell.

I just ordered 4x Samsung LM561C S6 leds 80cri, 3500k quantum boards.
I will be running them per 2 boards (because of the rectangle shape of the grow space) connected to a meanwell HLG-120H-48B.

i saw somewhere on this forum that a heatsink is not needed for these 128 boards because they both run at 60w each. Since my grow space is very small and I just want to be sure everything is safe I wanted to buy heatsinks. By coincidence i ran for only 5 euros into 16 alu pieces wich are 1cm thick. 4 alu pieces can cover 1 board.
But there is maybe a downside. the corners of each alu plate are rounded so if i put them together, there will be a small part in the middle of the board uncovered.

another possibility is to place 4 alu pieces next to each other, but than the sides of the boards wouldn't be covered by 1cm on each side.

picture top: https://1drv.ms/u/s!Ag2xnRyHNZnghFOAbEkxgDHFwUsn
picture side: https://1drv.ms/u/s!Ag2xnRyHNZnghFLYJtlpom7xlDU9

- Does this matter since i normaly wouldn't need a heatsink at all?
- can i put thermal paste into this spot for fully coverage?
- would it be wise to but thermal paste on the whole board?
- i will clean the alu parts to make them 100% flat
- Will the meanwell HLG-120H-48B be fine for 2x 128 60w boards?

greetings,

kang

[unkle_psycho]

I don't really know about quantum boards, but I have repeatedly bumped into the claim that that model does not need a heatsink.

Need is a relative concept though, I haven't seen much reports of people blowing their systems with heat (except with cheap chinese products)

I spent some time exploring how hot my vesta strips got under different electrical loads, since I live in Finland and I couldn't find anything that pleased me. Even a simple alu u-channel cost almost as much as a strip, so I was planning on just adding more strips. Finally someone had some weired shaped extrusion left over, so I used it.

But besides avoiding the temperatures that would lead to total failure, temperature does destroy a little efficiency, if I remember right, 20c of added temp reduced 2-3% of efficiency for my strip. I also saw someone claim that every 10c of reduced temperature expanded leds life by some ridiculous amount. It's all give and take unless you live in an environment where temperatures are one of your greatest challenges.

Heat-sinks work by surface volume, so the thickness gives little benefit without wings, but they are not very expensive either.

[kang]

Nice that you are using strips. I also thouhgt about buying those. Cooling should be also more easy since you only have to use the space of 1 strip.

Interesting that cooling the leds by a few degrees celcius has this many advantages. But would it Harm the quantum board if a small part isn't in touch with the alu?

[unkle_psycho]

I don't think a little corner should matter too much, but not sure either. I was testing my strip temperatures before I attached the heat-sink, and I was surprised that when I lit a single channel out of two, one side of the strip was around 30c, and the other at 50c. Pretty bad heat conductivity within the board i guess.

Perhaps some leds running hotter then others could create some problem, but it seems to me it happens anyway, for example in vertical strips one and seems to get a little hotter then the other. In constant voltage systems such imbalances matter more and can lead to catastrophic failure, but thats where my knowledge ends.

I did notice many people run their quantum boards at 50c. Thats surprisingly hot. Don't know what max temp is, in my vestas I think its 80c

[kang]

that's 50c on the bigger quantum boards like 120w+ i guess. I wonder what the c would be on a 60w quantum board like mine without and with heatsink. Was the 50c on boards with or without heatsinks 80c at max seems alot to me?

[unkle_psycho]

Not sure which QB, and now a quick search on QB temperature didn't bring much up either...

The temperatures I was talking about were on vesta strips, not samsungs, but I guess very similar powered diodes.

The strip size is 31mm x 560mm, and the maximum power for one strip is 50w. I tested them without heatsinks at 12.5w per strip and they were very fine. Then I ran them at 25w, and they were about 50c. When hit by the small ocillating fan in my growroom the temps seemed stable and I ran it for a day.
I glued some 55mm wide alu channel with a little 20mm wing on today, and I'll see the temperature difference tomorrow, when I connect the wires.

How many % of the max rated power are you planning to run? Is 60w their maximum power? I can't Imagine you reach over 70% power with the heat sink, or 50% without, and I imagine you would be around 50c?

[kang]

I'll be running 2 boards 60w each on meanwell hlg-120h-b with a 100k potential meter. I think they will be around 50c but not sure what the heatsink will do since it's just a thick alu piece. i really hope that the part wich is not covered wouldn't be effected by not being in touch with the heatsink.

How much did you spend on the strips and what is your driver? how was the temperature after 1 day with the alu channel? Strips sound really attractive to me now.

[unkle_psycho]

I guess it will help a little. It still evaporates better then the board, and heat-sinks are an area of diminishing returns, so the first little bit is the most important. Takes more and more to get less and less further cooling.

I saw one shop selling the qb288 say that it could be run up to 60w before it needs an aluminium plate or heat-sink. https://www.ledgrowlightsdepot.com/prod ... ards-4000k

And here they seem to be talking about the subject, but I don't have time to dive in....

https://www.rollitup.org/t/diy-with-qua ... 9/page-129

For me I ordered enough top light for a 2x4, but enough side lighting for a 4x4... I got 9 2foot vestas, 24 1foot vestas, and 10 75w Thomas Research Products drivers. The whole lot was 250$ The top light will run at 225w, but it has 450w of drivers. 3 for both color temperatures. If I want over 225w, I don't have the full range of color tuning, I start heading towards the 3850k spectrum of running both channels equal.
Then I have 4 drivers and 24 1foot strips left to build side lighting. It's 6 strips per side, I have no experience, so in my next grow I'll find out if it's enough coverage for the sides.

I can also just light one driver and light 3 strips covering about 40cm x 60cm, or a bunch of other configurations.

Kinda exited for now, my current run is done in about a week, so I get to see the new lights on a fresh grow soon. I still I'm not sure if the driver choice was perfect. It was a really good deal, and this way I really get full versatility, but drivers are the least aging component, and its only 88% efficient... Better not worry too much and grow something nice

[kang]

I really wonder how much the strips will add. Seems really nice that you can spread the light in your grow space so well, and even on your spectrums. Really curious about your g/w after the grow! what are you aiming for?

[unkle_psycho]

I really don't know what to expect as I will only be growing two plants, but large. I found my genetics though.

I have hit 2.5g/w in the 90's, which was the last time I grew inside. To me it's simple, you just optimize the amount of budding sites in the useful area that the light penetrates. I'm finishing the last 2 weeks of my pheno hunt with the leds, and the penetration with just top lighting is already crazy compared to any single source light I ever saw.

But I've only done one run with these genetics, and none with leds.