Products are rated as needing 400 Linear Feet per Minute (lfm) of air flow,
the cooling fans in the case are rated in Cubic Feet per Minute (cfm).
I don't believe it is a straight forward conversion, because the dimensions of the box through which the air is flowing , are usually different than the size of the fan shroud.
If some one could shed a little more light on this I would appreciate it.
Thanks in advance