Actually, talking about water/electricity interaction in refrigerators, lab equipment, etc, misses the very simple point - a probability of a leak is proportional (as a good approximation :) to the number of moveable components (PCBs, connectors, etc) in the system. In a typical CO it's tens or hundreds of thousands. --vadim PS. Water is not a good coolant, and even distilled and deionized water tends to pick ions from metal parts rather quickly. Spirits are flammable; CFCs are bad for environment. There's also an issue of toxicity. Of course, everything is doable, but what is the cost? Off-the-shelf components are all designed for air cooling. Switching to liquid cooling means a lot of custom stuff; which is expensive and which takes a long time to design and manufacture. PPS It is not voltage which matters, it's current :) Even if leaks do not cause shorts the moisture accumulation may corrode parts leading to mechanical shorts, it also may cause excessive cross-talk. Sporadically malfunctioning equipment is much worse than flat-out burned out. PPS Finally, getting your hands wet makes your changes to get killed by electricity _much_ higher. 48V won't do you any harm if your hands are dry, it may kill if they're wet.