HVAC Engineers - Static Pressure Calculation Q&A

[pbrme]

I'm wondering what other engineers in the HVAC industry are using for static pressure calculations. Feel free to reply if you use spreadsheets, any software or other programs. My mechanical group is currently trying to develop a more streamlined approach using Revit, but it seems to have pitfalls. So I'm curious what others in the industry have tried or have otherwise found useful.