Liquid nitrogen
Liquid nitrogen may be used to cool an overclocked PC.
As
liquid nitrogen boils at -196
°C, far below the freezing point of water, it is valuable as an extreme coolant for short overclocking sessions.
In a typical installation of liquid nitrogen cooling, a copper or aluminum pipe is mounted on top of the processor or graphics card. After being heavily insulated against condensation, the liquid nitrogen is poured into the pipe, resulting in temperatures well below -100°C.
Evaporation devices ranging from cut out heat sinks with pipes attached to custom milled copper containers are used to hold the nitrogen as well as to prevent large temperature changes. However, after the nitrogen evaporates, it has to be refilled. In the realm of personal computers, this method of cooling is seldom used in contexts other than
overclocking trial-runs and record-setting attempts, as the CPU will usually expire within a relatively short period of time due to temperature
stress caused by changes in internal temperature.
Although liquid nitrogen is non-flammable, it can condense
oxygen directly from air. Mixtures of
liquid oxygen and flammable materials can be
dangerously explosive.