[BC] Fire suppression

[Alan Alsobrook]

Dave Dunsmoor wrote:
> However, Rich's scenario with doors clanging shut in a room room being
> fiilled with Halon would leave one with the heebie-jeenies, even if there
> were an emergency "open here" button on the wall.

Let me throw in some stuff.. Halon works NOT by removing oxygen, but by
interrupting the chemical chain reaction of combustion. The fire
triangle we were all taught way back when has officially been replaced
with the fire tetrahedron having the traditional heat, oxygen, and fuel,
but adding a fourth side of Chemical chain reaction. One of the selling
points of Halon way back when was that you could be in with it and not
be hurt by the halon. Another Halon fact any properly installed halon
system is supposed to be a "pre-action system" ie: an alarm sounds x
seconds (usually 30) prior to discharge. This is to give you time to
evacuate and or Hit the ABORT! button if it is a false activation. Also
a halon system should require not 1 but 2 sensors to indicate a fire
prior to triggering. That's part of the reason why you have many
detectors in halon protected areas.  How can halon kill you? if it is
discharged into a fire it can convert into phosgene gas which is deadly
in small concentrations. One other thing to keep in mind, should you
even have to ventilate out an area that has had a halon release make
sure it doesn't travel into an area where any internal combustion
engines are running. If it does get ingested by a running engine, expect
to have to replace the engine in a few weeks. (It makes a acid with the
oil during combustion which eats the block up).

-- 
Alan Alsobrook CSRE AMD CBNT
St. Augustine Fl. 32086 904-829-8885
aalso at Bellsouth.net