The fans consume just one-third the power of traditional computer fans; and they're smaller than regular fans, which means engineers can make the servers thinner and pack more electronics into them. The prototype HP fans are built from sturdier, more reliable parts than today's computer fans.
HP and rivals are also working on other ways to solve the problem of excessive heat. There's water cooling, in which heat sinks are replaced by "water blocks" with channels for flowing water; phase-change cooling, which is similar to traditional refrigeration; and Peltier cooling, based on the Peltier effect, in which a current passing through two types of metal causes one to heat up and the other to cool. But a flow of air is still the simplest way to disperse heat.