When performing a room-by-room calculation in Cool Calc only enter the wall lengths of the outside walls and partition walls in the above grade wall section of step 2. Interior walls can be omitted.
A partition wall is a wall separating a conditioned space from a non-conditioned space such as a garage or non-finished portion of a basement.
Although interior rooms will have no wall load the interior rooms should still be included in a room-by-room calculation so the system can determine the overall volume and floor area of the home. This information is required for the infiltration and duct load calculations.