This is another reason not to adopt the 2005 Code.
The situation is that the Romex cables pass through a 1 1/2" thick stud and the rest of the hole is sealed with foam. It should be emphasized that this is only for a distance of 1 1/2".
Earlier editions of the Code recognized that the copper will conduct away any built-up heat. Thus the permission to bundle for up to 24" without derating.
This section of the Code should not be adopted. The Code panel doesn't understand the physics involved.
~Peter
