Difference between low temperature radiant (const/var. flow) vs. cooling panel radiant convective water?

edit

Hello, I am trying to model ceiling radiant cooling panel (the one where you attach a tube containing flow of chilled water to an aluminum, then hang it in the ceiling) using OpenStudio. There are two options for this, Low Temperatue Radiant (constant and variable flow) and Cooling Panel Radiant Convective water. Which one is more accurate for my use case? TIA.