Of course, I simulated one apartament and I modeled in SpaceClaim, after I put in Ansys Mesh for generation of the mesh with the named selections (inlet and outlet). In Fluent, I insert velocity (2.6 m/s) in inlets and outlet pressure 0. 

In CFD post I can extract the velocitiy but I can't extract the Air Change per Hour. I think some in expressions menu.

Thank you.