How to add a return air path for bedroom

I this video I describe how to add a return air grille to a room so you can leave the door closed and still get adequate air flow.

[@arielrodriguez6980]

Basically it is not connected to a duct in your case it is just a pathway with a grill on each side of the wall correct?

[@kwm380]

Yes, it's just a pass-through in the wall.