Principle of Operation
Asetek's Vapochill Micro is based on heatpipe technology. Inside a metal tube a liquid is held at low pressure. Because of gravity, the liquid sinks down to the cooler base. Now when the temperature exceeds the boiling point of the liquid, the liquid evaporates (turns into gas) and rises in the tubing. While it rises, it gives away some of its heat to the surrounding tube, which conducts heat to the fins from where the heat goes into the surrounding air. This slowly cools down the R134A gas. Once the gas reaches a temperature below its boiling point, it condenses on the walls of the tubing and sinks down to the bottom as liquid again. This process is going on indefinitely - it does not create any noise nor is there any mechanical wear.
At the bottom of the fan duct is a small opening where air can escape and cool the other components on the motherboard, like memory and power regulation circuitry around the CPU.
Despite its big size (it is taller than a full-height PCI card), the cooler is very light-weight. The cooling fan is installed with some plastic pins, which are very easy to get in, but a pain to get out.
The transparent plastic fan duct is made from very thin material and feels really cheap.
Asetek ships the Vapochill Micro with preapplied thermal paste. The thermal paste is protected by a solid plastic cap, to avoid shipping damage. Personally I do not like this idea, I prefer to use my own thermal paste (Arctic Silver 5). While I am sure Asetek has given good care to the selection of the paste, there is no specification available. Which is why I will use what I know works good for me.
However, for novices this makes the application even easier, since they do not have to mess around with thermal paste and there is no chance that its application will be skipped, because of user error or lazyness.
The copper base does not look very flat to me, it also has small dents, scratches and a round indent which seems to be from manufacturing. But performance testing later shows that this does not degrade cooling performance, maybe a good lapping is in order.
Asetek ships the Low-Noise and Extreme-Performance versions of the Vapochill Micro with this PCI slot fan controller. It uses Pulse-Width-Modulation for optimum fan control. The range of Low to High is very wide and covers most settings you would want to run a fan at. It is not possible to accidentially turn off the fan by turning the knob all the way to the left.