Re: Halon?
Uhm, sprinklers and Halon/Inergen/etc systems don't fill the same purpose.
Gas extinguishing systems are typically triggered by sniffing the outgoing air for tiny amounts of combustion byproducts. This catches really tiny fires really early, but if you have a fire that's big enough or recurring (or fuelled by an oxidiser in case of oxygen-depleting systems) they are useless as they will go empty.
Sprinklers are triggered by the sprinkler head physically heating up to the point of a wax plug melting or a glass bar breaking due to expanding liquid inside it (in addition to the system being pressurised by a fire alarm going off in higher-end systems). This catches big fires before they turn into huge fires.
Sprinklers are there to stop the entire building from burning down with people inside it - most of your servers will probably be toast before they even go off, and when they do they will obviously break the rest. They protect the building itself and the people in it.
Gas discharge systems are there to stop a small fire in some gear from taking out anything else - they won't save you from a fire that actually threatens the rest of the building. They protect the equipment but not the building or people.
You'll even see both fitted in quite a few installations.
Also, where does this pathological fear of Halon discharges come from? Halon by itself is fairly non-toxic. I wouldn't recommend picking up a habit huffing it - or doing the classic Halon sales demo of standing in a both as it's discharged inside it - but a single exposure isn't gonna hurt you.
At most being around when a large system is discharged might cause damage to your hearing, or being hit by a flying object.
The reason it's no longer used much is because it's a potent ozone depletor, not that it's a hazard to people.
CO2 systems - still widely used, though not in computer settings - are much more dangerous to people.
The warnings for these basically say "when the klaxon sounds, get out or you WILL die".
Biting the hand that feeds IT
