That's darn interesting. I have to admit, having never personally witnessed the adverse effects of bundling Romex, and having seen it ignored by almost every local "authority" in residential electrical construction, I was darn skeptical about what threat bunlding posed.
Obviously, the bundling does have a serious impact on heat generation.
However, I would have liked the study to address several things: What was the average temperature rise for a single cable carrying the same load as identical bundled cables?
And speaking from personal experience I can say that in a lot of resi. construction cables are regularly bundled for distances far in excess of 24". They may not be packed together in a hole and fire-stopped, so their is certainly more heat dissipation, but by how much? What happens when that same bundle is covered with ten inches of blow-in fiberglass?
I think I'll be a lot more cautious about how I route cables now after seeing this.
-John
