Originally Posted by jwalker
I think that is true for Co2 but at close quarters, as might be the case in a rib, the cooling effect is substantial and if you release Co2 into a small fire there is often ice on the surface where the flames have been extinguished. Whilst displacing the air (hence oxygen) is a benefit, if you do a bit of research on the Halon replacement gasses, I think you'll find they do absorb heat. If they just displaced the oxygen, it wouldn't matter which inert gas was used.
I would guess that they initially remove heat to below a point of ignition then they prevent reignition by hanging around excluding the oxygen. As I said, just guessing.
No idea on Halon but I am pretty sure the cooling effect of CO2 is down to basic physics. You are rapidly boiling a pressurised liquid into a gas and therefore that absorbs heat - a bit like the principle an air con system works on I suppose.
I use CO2 bottles for my beer brewing at home and if you trigger the nozzle with your fingers you can end up frozen to it... the cooling effect is huge.