With reference to recent questions about overclocking (ie. What are the overclocking capabilities? ), is it possible to immersively cool the Raspi?
Presumably such a system would have to rely on finding a coolant that is non-toxic, non-conducting, and cheap.
There's also the physics of boiling - although a boiling coolant would be most effective, it would need a more sophisticated level of containment to avoid vapour escape.
While it may be possible to immersively cool the Raspberry Pi, currently there is not much of a reason to do so.
There is some discussion about heatsinks and cooling, but the general consensus is it's ultimately not necessary, even if it's possible. In the previous link, Gert van Loo, who is a part of the Raspberry Pi foundation says:
I know it sounds strange to a lot of people, but temperature is not the limiting factor for this chip. It works or it does not. Cooling the chip the might gain you a fraction of speed, no more.
If there is, at best, a marginal benefit to adding a heat sink, it's hard to imagine that immersively cooling a Raspberry Pi is necessary or even conceivably beneficial.
For educational purposes, you may try Liquid Paraffin cooling like here : http://aquariuspc.it/eng_main.php
I have seen people build entire desktop computers in what are effectively fish tanks, and using mineral oil as a coolant. For reference give this a video a look.
I imagine if you are willing a similar thing could be done with the Pi, but your gains performance wise are not going to be very big. The Pi uses a SoC chip, and the RAM sits on top of the CPU, so effectively by cooling the chip you are cooling the RAM. Although this leads to the CPU running slightly cooler.
Bear in mind the Pi is designed to run passively cooled and will only thermal throttle at 85°C anyway.
For extreme overclocking liquid nitrogen is the way forward, give this a look.
