Looking to buy a USB powered laptop cooler, found two decent ones on sale, one uses 2x 92x92x25mm fans, the other uses 4x 60x60x10 fans.
Both are rated at 5volts:
2x92's: 1700-1900rpm, 18-20dba
4x60's: 1900-2600rpm, <24dba, quoted at 40cfm
I don't know how much air the 92's move, and googling offered too many options depending on current. The additional advantage of the 60's cooler has, if you look at the below pics, big wide grilles, enhancing air flow (?). The cooler with the 92mm fans is a bit more expensive, but the price is negligible if it moves more air.
4x60mm fans
2x92mm fans
Both are rated at 5volts:
2x92's: 1700-1900rpm, 18-20dba
4x60's: 1900-2600rpm, <24dba, quoted at 40cfm
I don't know how much air the 92's move, and googling offered too many options depending on current. The additional advantage of the 60's cooler has, if you look at the below pics, big wide grilles, enhancing air flow (?). The cooler with the 92mm fans is a bit more expensive, but the price is negligible if it moves more air.
4x60mm fans
2x92mm fans