Shmutz Under Pressure

This month's brain teaser was answered by two firefighters, each saying the same thing but in very different ways. Both are worth presenting.

The question was, "Where would you find the overpressure region, the under pressure region and the neutral plane?"

The academic answer, "The neutral plane is the region in a container fire (as in structure or contents fire) between the overpressure where hot gases are flowing out - as in black smoke or even flames and the underpressure - air flowing in. In a doorway, smoke and flames will usually flow thru the upper third or half of the opening while incoming air will be in the lower third - in between the two is the neutral plane.It gets lots more complicated if windows or basement opening are providing the underpressure."

The succinct answer, "a nicely undisturbed compartment (room/building) fire". we usually mess it up so it all becomes shmutz."

Thanks, and well put...