Aceton kan ook, net als een heel scala aan andere materialen, maar in consumentenheatpipes en dus CPU-koelers wordt om veiligheidsredenen vrijwel altijd water gebruikt. De grote truc is dat men het onder lage druk gebruikt, waardoor het kookpunt opeens gecontroleerd kan worden en precies op het meest nuttige punt gelegd kan worden. Daarnaast is water een relatief goede vloeistof om heatpipes mee te maken o.a. door zijn oppervlaktespanning, alleen ijsvorming is een probleem bij temperaturen onder nul, maar die kom je in een PC toch niet tegen.
In zekere zin heb je dus met heatpipes ook waterkoeling

Using a powerful and hazardous reagent like ammonia for a consumer-market device would be out of the question — but there is no need for such a heat pipe to operate at low temperatures. So theground rules are changed. Computer heat pipes need only to operate from room temperature, ≈20°C up to perhaps 70°C. This opens the opportunity to use one of the very best heat transfer fluids that is available for us — water, just plain (but very pure) water, H2O. The pressure inside of water heat pipes is less than 1 atmosphere (14.7 psia). For example, at 20°C the pressure would be 2.34 kPa (0.34 psia) and at 50°C a pressure of 12.3 kPa (1.8 psia) would be observed. Operating at lowered pressures, such as noted, is not a great concern because a heat pipe must be truly sealed, and water does not care until the temperatures would get nearly to freezing, 0°C.
Heat pipe wick operation will be quite good with water because the surface tension of water is relatively high, meaning that a water heat pipe wicking operation will be somewhat better in the anti-gravity situation than many other fluids can support, including ammonia. Nevertheless, the water heat pipes that I have found all are positioned in the gravity-assist position — the condenser section is located above the evaporator section.
Interessant leesvoer.