Tom, I don't know if you read them or not, but I have some thoughts and sizing suggestions on air inlets on my site.
You can find them (
HERE ).
I also today added a spreadsheet to my site that uses the formulas in those suggestions to figure an air inlet size (
HERE ).
I would remember that when you read anything on my site you should always double check with a second source or so to see if you feel comfortable with the information before you use it. This might be a good idea for anything you read.
Hope this stuff helps a little,
Sum