Remove geometry on "inside" I have a mesh that has a internal geometry but not like vertices inside of a closed geometry but rather the faces that are not visible from the outside let me explain with an image: 





as you can see the red area indicates the faces on the "inside" how would I go about removing these?   

I want to remove the internals to reduce the vertex count! since I won't ever see them anyway.

If my question is unclear  or needs extra info let me know so I can clarify!
Try the select Interior Faces Command and see how close it gets you.