Custom passive PC cooling (part 2)
Here is the continuation of the story with passive cooling for PCs. Yes, a lot of time has passed since the first part, and many different concepts have been considered. The best option in my case looks like this:
Now let’s look at it in more detail and consider how I came to it.
It is optimal to have a radiator on top of all components so that the air draft cools the components even before the main heating.
Convenient arrangement of components to connect them to heat pipes and reduce their bends.
But the most important thing here is the radiator itself. Previously, I wanted to cast it from aluminum (you can do that too), but I liked the option of a prefabricated radiator made from aluminum sheets better. Yes, you will need a lot of thermal paste to connect them all, but I think this way the casting flaws will be better visible.
The dimensions were selected using the power selection method (more on this a little later), and we should have three main parts:
The ratio of their sizes was selected using the selection method: the blue part is under the CPU, the orange part is under the GPU, and the center is green. The empty space between them is also not empty – there will be heat pipes there, and they will be compressed between them. Then the heat will be transferred better, for example, if the load is only on the CPU or only on the GPU.
I plan to place all the elements inside like this:
It is better to completely remove the housing of the power supply. Perhaps there will be two power supplies in order to remove the fan in them and so that they work almost without load, or buy one expensive power supply immediately with passive cooling.
The height of the radiator was also selected using the selection method, like all sizes, best for this power (120W CPU + 220W GPU).
The thickness of the sheets is 3 mm, the distance and aluminum spacers between the sheets are 6 mm (excluding thermal paste). The height of 24 cm is actually excessive, as tests have shown. It is better to increase the length (add more sheets) if you need more powerful hardware.
Well, here are the tests themselves. In fact, I made over 20 different combinations of radiator sizes and shapes. Considering that in 3600 seconds (1 hour) the maximum temperature of the radiator was 51 °C, you can add another 10 °C relative to the temperature of the chips to the loss in heat pipes, thermal paste and all connections, and also add heating of the air in the room in the summer to 30 °C ( tests were at 20 °C ambient). Then the maximum temperature is 71 °C, which, in my opinion, is an excellent result.
By the way, the renders show slightly different radiator sizes, not the same as in the screenshots with calculations. I didn’t save everything, here are the dimensions from the calculations:
And here there was supposed to be a part of the article with assembling all this, but so much time passed that I decided to save up for even more powerful hardware. Yes, it would be possible to increase the size of this radiator, but I’m looking askance at the RTX 5090, and judging by rumors, there will be 600W consumption. This is almost 3 times more, and the radiator is needed significantly more. It will be difficult to find heat pipes of this length, and the mass will already be very significant.
For such capacities there is another solution. I haven’t firmly decided yet, but there is an option from the first part: you can simply hide all the filling behind the heating radiator and use water blocks. Yes, it sounds like a crutch, but the power reserves there will be much greater, and the pump noise is almost inaudible from some manufacturers. If someone imagines old cast iron batteries, then it will not be so “collective farm”; there are more beautiful options, including dark colors, for example:
However, there are many different designs. The only thing is that the distance to the wall will be a little greater than usual. I think the entire filling can be reduced in thickness to 7 cm.
At the moment I am using a TV instead of a monitor and I think that it would be quite possible to fit the heating radiator and all the stuffing behind it. So there are many options to solve this problem.
If anyone has ideas, suggestions or criticism, I'm waiting for you in the comments.
