• Save 15% on ALL SFF Network merch, until Dec 31st! Use code SFF2024 at checkout. Click here!

Cooling [SFF Network] Passive Cooling - An Experiment

CC Ricers

Shrink Ray Wielder
Bronze Supporter
Nov 1, 2015
2,234
2,557
My idea of passively cooling a GTX 950 now looks more feasible in SFF with MSI's 75w models.

My idea is to use a large extruded heatsink that is shallow but covers the entire surface area of the entire side of the case. The design is something like Streacom's NC2 but vertically oriented (so heat fins point sideways) and larger. The CPU would be cooled separately, using a low-profile CPU cooler with intake on the opposite side.

The most time consuming part would be cutting down the heatsink to have it mount well on the GPU chip while also not interfering with the taller components such as capacitors.
 
Last edited:
  • Like
Reactions: confusis

jtd871

SFF Guru
Jun 22, 2015
1,166
851
Black is the best thermal body in terms of being a absorber or emitter - so even though a layer may be added to make the cooler the darker colour, the benefits of the heat emission may outweigh the losses from adding a layer of plating/paint.

Dear heatsink manufacturers: please get on with the R&D into copper sinks coated with carbon nanotubes.
 

EdZ

Virtual Realist
May 11, 2015
1,578
2,107
Surface colour has an effect on radiant heat emissions, but CPU heatsinks are so cold (compared to, say, molten salts or space-based fission reactors) that it is likely the only effect a coloured coating would have is the small thermal resistance of the coating itself to conductive heat transfer with air.
A textured coating could have interesting effects, but then you start to get into turbulent vs. laminar flow effects, and you dive down a CFD rabbit-hole and start proscribing fans with tuned CFM performance and stacked-tube flow laminisers.
 
  • Like
Reactions: Honegod

confusis

John Morrison. Founder and Team Leader of SFF.N
Original poster
SFF Network
SFF Workshop
SFFn Staff
Jun 19, 2015
4,326
7,427
sff.network
Surface colour has an effect on radiant heat emissions, but CPU heatsinks are so cold (compared to, say, molten salts or space-based fission reactors) that it is likely the only effect a coloured coating would have is the small thermal resistance of the coating itself to conductive heat transfer with air.
A textured coating could have interesting effects, but then you start to get into turbulent vs. laminar flow effects, and you dive down a CFD rabbit-hole and start proscribing fans with tuned CFM performance and stacked-tube flow laminisers.

That's a good point (albeit with so many big words o.o ) In saying that, would a black nickel plating have a negative effect on aluminium fins?
 

QinX

Master of Cramming
kees
Mar 2, 2015
541
374
That's a good point (albeit with so many big words o.o ) In saying that, would a black nickel plating have a negative effect on aluminium fins?

In theory it should, you are adding and extra layer that has a thermal resistance. In practice you won't see any perceivable difference.
 

Stevo_

Master of Cramming
Jul 2, 2015
449
304
The experiment showed more than anything the sub-optimal orientation of the heat pipes dominates performance. When I had my AXP100 horizontal(optimal) in my Node304 it cooled much better than with motherboard in the vertical position of my L2, heat pipes running left-right. For top-down cooler Noctua lists on their site the one orientation to avoid when the mobo is vertical is with heat pipe bends at the top, pretty much defeats vapor cooling.
 

|||

King of Cable Management
Sep 26, 2015
775
759
In theory it should, you are adding and extra layer that has a thermal resistance. In practice you won't see any perceivable difference.

There may be a very slight drop from the intramaterial conductivity, but with a void-free plating, it should be minimal. I belive they were wondering about additional gains improving the emissivity from black-body radiation. Radiation isn't the best means by which to remove heat, but keep in mind that electronics in low earth orbit (LEO) and outer space are cooled exclusively by it (there can be intermediary devices, but it is radiated away at some point).
 

Cuzza

Trash Compacter
LOSIAS
Jul 15, 2015
38
39
Radiation really must be negligible, otherwise everyone would have been making their heatsinks black for years.

I would like to see some testing of methods to increase convection. You should make up some cardboard shrouds or something.
 

Kooki

SFF Lingo Aficionado
Mar 30, 2016
129
56
I see you finally got the new motherboard! Cheers :cool:

Quick question: Does the Cryorig C7 fit nicely this time around on this mobo?
 

confusis

John Morrison. Founder and Team Leader of SFF.N
Original poster
SFF Network
SFF Workshop
SFFn Staff
Jun 19, 2015
4,326
7,427
sff.network
no new board, the atx board of the extreme rig is my old pc! The cryorig fit fine on this board though :)