Samsung strip build (mainly flowering).

[crazyphil]

Hi Warbar, I think, I have to apologize for what I think to be a huge mistake from me yesterday.
I have good news for you
Your plate should take 5 W Heat out .(Al thermal conduct. = 185 W.m².c, Surf. of you plate =0.0276 m²(incl. sides)=5.11W)
But this is for every single °c between the plate's temp. and the air temp. touching this plate
So , I guess that you will easily get a 5 or more Delta T° with your room fan running.
Should in fact be a piece of cake if you plan to run them at 30-35 ° with a room temp of 25°
If you plan to run them at lower temp, your building with the 2 dble rails can dissipate : 16W, bringing you to a 2°c delta
Hope this times my maths are good , if some experienced people could comment !!!

[unkle_psycho]

Hi Warbar, I think, I have to apologize for what I think to be a huge mistake from me yesterday.
I have good news for you
Your plate should take 5 W Heat out .(Al thermal conduct. = 185 W.m².c, Surf. of you plate =0.0276 m²(incl. sides)=5.11W)
But this is for every single °c between the plate's temp. and the air temp. touching this plate
So , I guess that you will easily get a 5 or more Delta T° with your room fan running.
Should in fact be a piece of cake if you plan to run them at 30-35 ° with a room temp of 25°
If you plan to run them at lower temp, your building with the 2 dble rails can dissipate : 16W, bringing you to a 2°c delta
Hope this times my maths are good , if some experienced people could comment !!!

This is great, I doubt anyone will come and contribute to these numbers, but perhaps someone will. I think what your formula is missing is the effect of air movement. It's surprisingly powerful. You might find some literature on the matter by searching forced convection.

Here there is some more detailed information on calculating dissipation, don't know if you will find it interesting.
https://www.lisafea.com/pdf/Convection_ ... icient.pdf
On page 4 they talk about led heatsinks.

Here there is an online heatsink calculator that includes a section on forced convection:
https://heatsinkcalculator.com/version- ... lator.html

[unkle_psycho]

I looked into the heatsinks and in this part of the world they cost a fortune. The equivalent of $550-$600. As a cheaper(about a third) alternative would 2x 500mm lengths of Aluminium Double Channel 16mm x 10mm x 1.3mm https://hardware-warehouse.co.uk/profil ... mm-10mm-2m fixed with thermal paste/tape to the outer edges of each flat bar creating more surface area do the job.
End profile of Flat Bar Alloy with 2x Double U Channel?

I like your thinking. Do it type of guy?

If I understood you right, you would use three separate elements to build the heatsink? First a flat aluminium, and then two narrow finned extrusions on that. I have built heatsinks using two narrow finned elements, I just didn't have a flatbar under them. It sounds like it will cost an arm and a leg. The result would certainly work, and allow you to just get at it. If you have the patience, there probably are alternatives... let me just propose a few very different ones.

1. At the power level you are planning, aluminium sheet would already probably dissipate your heat. Price would vary by thickness. Thickness is not a big factor in heat dissipation, espesially when talking about 1mm of thickness, its balancing stiffness and weight.
2. Ordering good heatsink from china feels irritating because over half the price comes from delivery. As a positive that delivery is DHL and comes in fast. I imagine that you could get some real 'heatsinkUSA' style extrusions for a little over 10$/m delivered. You might not have to spend as much as your planning, but if you do, this might be worth looking into.
3. For a QB style build you might want to google aluminium baking trays... there are many sizes. For example a 600mm x 400mm tray is long enough for these strips.
4. There are some cheaper extrusion types, although you might prefer the finned shape your image shows. I recently noticed a type of aluminum guide rail used to make cement floors. An extrusion 3m long and 100mm wide is about 25-30e. I found someone who finished building their house and got 6m for cheap. Will make 4 120cm extrusions out of them. What does 20x40 modular extrusion cost there?
5. have a look at the larger second hand sites. Roll a joint, just write aluminium in the search bar and scroll through what comes up. Of course you can first search for aluminium extrusion, but the general aluminium search might give you some surprise well worth your time.

Parts being expensive, you could buy or import modular extrusion... 15x30 or 20x40 to hold the strips. Then add a single extrusion as an end piece to hold the heat sinks in place... pretty much the same structure as the new fluence designs. Simple and saves on material.

Here extrusions cost even more then England, but construction companies are quite wasteful with them. I started to network with construction guys, do little favors for them, and they collect scraps for me at their sites. I receive all kinds of sizes and shapes for free, and already have a couple of sacks of extrusions laying around. Construction sites usually have these huge industrial dumpsters they might allow you to look into.

[Warbar]

Thanks for your maths Crazyphil.

Hi Warbar, I think, I have to apologize for what I think to be a huge mistake from me yesterday.
I have good news for you
Your plate should take 5 W Heat out .(Al thermal conduct. = 185 W.m².c, Surf. of you plate =0.0276 m²(incl. sides)=5.11W)
But this is for every single °c between the plate's temp. and the air temp. touching this plate
So , I guess that you will easily get a 5 or more Delta T° with your room fan running.
Should in fact be a piece of cake if you plan to run them at 30-35 ° with a room temp of 25°
If you plan to run them at lower temp, your building with the 2 dble rails can dissipate : 16W, bringing you to a 2°c delta
Hope this times my maths are good , if some experienced people could comment !!!

Unfortunately I realized my frame design had an issue regarding fixing the flat bars onto the spines. While looking for a remedy I saw a Greengene light/frame build video using 2020 alloy profile.
I've since managed to source some at the same price as U channel and will be using that instead. It cost around $6 a meter + $16 shipping.
The new design is clean and straight forward and extra cooling capacity can be added after if needed. I'll start ordering parts in a fortnight when i'm back in the UK. I'll do my best to document the build and know doubt i'll be asking for advice and confirmation.