92 mm fans
92 mm is the least popular size of the four taking part in this test, so it's no surprise that we received the fewest of these from manufacturers. You only pick this size if you do not have room for 120 mm or 140 mm fans. The efficiency of 92 mm fans is usually better than that of 80 mm fans, however.
This is reflected in the "all-out" graph where noise was not factored in. The Spire Cooling Fan 92 mm displaces 47.1 CFM, whereas the best 80 mm fan couldn't do better than 30.3 CFM. The reason: the motor takes a comparatively large amount of space in an 80 mm fan. From 92 mm upwards there is more room for the fan blades. The Spire is very loud though, with 56.3 dB(A).
Among the "more silent" fans the Cooling SWiF2-921 wins with 18.2 CFM. Its green/ yellow colour needs to match the rest of your system though. If you want a more neutral colour, the Scythe Kama Flow 2 92 mm 1200 rpm is worth looking at, as it is almost as effective.
The choice among the "dead silent" fans is pretty limited, only two are quieter than 30 dB(A) at 12V and 23 dB(A) at 7V. Of those two the green/ yellow Coolink SWiF2-920 displaces twice as much air as the Enermax Everest.