Starting off as a simple LISP command in AutoCAD this HAVC pipe size calculator was migrated to a standalone Java application.
Calculates HVAC minimum pipe ID based on GPM and FPS for numerous fluid types (found in the fluid density chart on EngineeringToolbox.com)
Includes a table to automatically calculate riser piping sizes per floor.
Read the README.txt file included in PipeSize.zip for instructions.