Good info all around on this subject. I used the calculations on the website listed and came up with the following:
14.5 inches high X 22.5 inches wide...divided each by 12 to get:
1.208' X 1.875' X 100 = 226.5 CFM
the (100 is FPM for cross draft venting since that is what Im planning)
That's with 0.0 SP (static pressure)...now I noticed Grainger has a 265 CFM @ 0.0SP Shaded Pole Blower.
I figure after adding the ducting I will need (which won't be much) I should be at around 0.1 or 0.2 SP...by the way this is just a guess I didn't actually do the calculation for static pressure. This will leave me with about 230 - 250 CFM which is plenty.
just thought I would share my findings. Thanks again for your help....oh yeah if my math is wrong let me know.