Revit to Rhino for CFD

Hi, I have been able to export simple building models from Revit for analysis in butterfly on rhino/grasshopper. There always is an element of cleaning and simplification required which for basic geometry is straightforward. Lately we have been getting much more complicated revit models and it takes a crazy amount of time to prepare these for CFD. Is there a way to create a manifold version of a revit model or with some sort of addon? Like an export building mass function?

Thanks

Hi,@absolutefour I researched this workflow last year.About the running time, it depended on which element are you export from Revit. You should ignore structural column or MEP equipment or interior stair/chair/desk etcs and only export the facade/wall/roof elements.
By the way I do not like using Revit model for CFD. I prefered to modeling geometry in Rhino.