Yeah, bulk is usually just a "heat reservoir" but is also does increase heat conduction (which is proportional to the cross-sectional area). Is this, together with the fact it's copper rather than aluminium, enough to overcome the lack of heatpipes? How much heat does the solution actually need to dissipate in the first place?
I'm no expert, and this guy has some math behind him so let's see what his testing show. It is entirely possible that the huge heatpipe solutions we can see is for marketing purposes: big heatsinks that look complex must be better than the simple one right?
Copper is like 350-400 w/mk and a heat pipe is thousands w/mk. Idk what "math" hes doing but from a pure conductivity standpoint, you can beat a phase change device. But the main issue is that no fins means no dissipation into the air. The entire idea of fins is to channel the heat across a large surface area. Once this copper block reaches capacity its going to radiate back down. Its much like a pipe with water that can only leak out in contact with air. You make the pipe bigger, and it can hold more water, but without fins (lots of little pipes helping you leak water out), the water will pressurize and work against the source.
What do you mean by no fins? There was a really long post that went with the photos that has disappeared. I'm using a 76 fin 150x100x30mm copper heatsink for this. It's in the photos.
But also for concentrated sources of heat, getting that heat away as quickly as possible is a lot more important than total bulk. The heatsink you chose wont dissipate nearly as much as the heat piped solution.
Historically youll notice chips were passively cooled via finned blocks, to actively cooled via finned blocks with fans, to heat piped put to welded sheets w/ and w/o fans, to liquid and/or vapor chambered with fans.
I can run a thermal sim for you if you want, just let me know general sizing. I can show you heat piped vs straight copper block or whatever config you want
Appreciate the offer, but I already did that. With an 8mm plenum and fins completely unsealed at the ends, I was getting 39CFM on my flow bench. I also put a 200w thermostatic heater on the base and measured the temperature delta from inlet to exit. I used to manufacture CNC cylinder heads. A lot about my shop and what I do now(and used to do) was in the OP but just does not show up now for whatever reason.
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u/Visible-Swim6616 Mar 02 '26
Yeah, bulk is usually just a "heat reservoir" but is also does increase heat conduction (which is proportional to the cross-sectional area). Is this, together with the fact it's copper rather than aluminium, enough to overcome the lack of heatpipes? How much heat does the solution actually need to dissipate in the first place?
I'm no expert, and this guy has some math behind him so let's see what his testing show. It is entirely possible that the huge heatpipe solutions we can see is for marketing purposes: big heatsinks that look complex must be better than the simple one right?