I think your question is whether you use total or static pressure in the equation. First thing I would suggest is checking the reference for your equation.
This reference says total pressure.
I don't have any specific experience in this but I would have expected static pressure only because I would expect that is ehat most people would have the capability of measuring. You might want to take that into account for your choice as well. You may also want to consult something like eng-tips.com for someone that knows specifically about fans if you aren't sure.
Overall it seems like you've figured out the flow simualtion part of it though. It might be helpful to others to mark your other posts as solved and note what you've learnt.