Originally Posted by
Pob255
Ahhh the golf ball, there we has a great example of fudging numbers.
That's not to say it's a bad fan, it's not, however it's also not 2000rpm it's about 1600rpm, but they claim that the blade design gives it the equivalent air flow of a 2000rpm fan and went so far as to adjust the rpm sensor feed as well, this also happens with some 11 bladed fans too.
This is one major factor with fans, you cannot trust the manufactures numbers for CFM and dBA.
CFM and dBA are very bad because there's no one definate test for them and the numbers can be greatly altered depending on the testing setup.
Use them as very rough guides and most fans from the same company can be compaired to other fans from the same company, but not always.