Over the years, I’ve collected many computer fans of every type in an effort to find the quietest, most efficient fans. The next three pictures shows most of my collection thus far:
This is a hard-to-find 15mm fan! Smaller than a quarter! I have yet to figure out what it would ever be used for since barely any air movement occurs. It’s a novelty item for sure!
Panasonic Panaflos tend to come out on top for air-to-noise ratio in every test I do
Crossflow “squirrel cage” fans are the most efficient but rarely work in an application for axial-type fans
Buying 24 volt fans and running them at 12 volts is better than buying 12v ones to run at 5v
The somewhat popular 7v trick of using the yellow and red wires for fans is harmful to some PSUs
For large fans which draw an amp or more, a 3amp regulator and pot are best for speed control rather than a large rheostat
Fans with built in thermisters are generally worthless
Thicker fans generate more air pressure than thinner ones
More blades = higher pitched whine
Delta fans are loud. If you want quiet, don’t buy a Delta “black label” fan.
Stacking fans for increased air pressure or air flow is inefficient. Get a new fan.
“Globe” brand fans, such as those used in Enermax PSUs, tend to be the best balanced of the bunch and vibrate less
Avoid sleeve bearing fans at all costs. The cost difference from sleeve to ball is too small to care about.
Decibel ratings are exponential; a 38db fan is much louder than a 32db fan.
It is better to buy a slower fan and run at normal voltage than a to buy a fast fan to run at half voltage.
Really large, slow moving fans have better air-to-noise ratios than small, fast ones…