[Amps] EBM Fan

[Mr. and Mrs. Magoo]

I'm another one who is being driven crazy by the fan noise on my Clipperton 
L and would like to replace it with an EBM which, I am told, runs much more 
quietly.

Can anyone give me an idea of how many CFM I should be pumping across these 
572Bs?  The fan presently installed is the original and I think it does an 
adequate job, but the make/model number plate is missing so I have no way of 
cross-referencing to a new unit.

Bill, VE3NH