Oak, there are quiet fans that will move as many CFM much quieter, but they cost about $70(or more). Working around video switch gear, it's like working around an idling Phantom II there are so many tiny high speed fans cooling things. The new installs use 36" x 40" "squirrel-cages" blowing 50-60* air at high volume but low pressure to make things quiet, and keep things happy. Control rooms are colder than OR's anymore. IC's and big hard discs don't like heat. Those little 4" 5,7,9 blade high-speed fans($8)(Nidecs and such) move 70-130CFM and use 5-6 watts doing it, while a 4-5 times quieter Roton "Hush-Fan" take 17-25 watts and are $70 and up and twice as deep. Look at Mouser Electronics and Thomas-Betts then look at All Electronics .com for surplus Chinese fans. It's much cheaper to make a noisey fan to move more air, with less power. Ain't it always sumpthin'....
