Re: [SGish] APC question

Odd. From the instructions I've heard for (automatic) halon firefighting
equipment, one has to clear the room/vehicle IMMEDIATELY. 

Not saying you are wrong, just boggled here.

Cheers,

   Derk

You will of course note that I never said that you would enjoy the
experience.. Just that you can still operate in it. Its main claim to
fame
is that for mission critical applications people can continue to work
for
quite a period of time. Its not nice for landing aircraft if the control
tower suddenly drops out of the communication loop!

The biggest problem designing the system is balancing the flow required
in
the given time to extinguish the fire but also keep the operating
environment from being obscured. Nozzle placement is vital! 
I used to hate doing computer suits as it is impossible to get people to
realise that when you change equipment around you have to recheck the
design. (What do you mean, I have to spend more money on some thing I
already own, didn't you design it right the first time!) 

It is even more vital with the new systems as if you change the volume
of
the protected space you change the amounts of gas needed for the system
to
work. Add more equipment and the volume of the protected space goes down
and Hence the CO2 levels go up.. People fall asleep... and Die. Remove
equipment and the volume goes up Inert Gas levels go down and the fire
is
not put out.. same consequences.

Another side note as most countries have signed up to the removal of
Halon
systems there has been the dodgy practice of just hooking up CO2 systems
to the old Halon pipe work..... Not a pretty picture....

Flynn Richardson
Special Projects Manager
Unilever Australasia