mm wrote:

If you have a heated building and open an overhead door 12 to 16 feet
high, for trucks, how fast will the cold air outside pour into the
building, and how fast will the hot air nearer the ceiling be forced out.

cfm = 16.6Avsqrt(HdT), for 2 Av ft^2 vents with an H' height diff and
dT (F) temp diff.

Nick