Question

An exhaust fan in a building should be able to move 5 lbm/s air at 14.4 psia, 68 F through a 1.25 ft diameter vent hole. How high a velocity must it generate and how much power is required to do that? 

Answer 1

C.V. Fan and vent hole. Steady state with uniform velocity out.

which is provided by the work (only two terms in energy equation that does not cancel, we assume V₁ = 0)