Thanks, Mad Hat. That is interesting. Apparently they're still legal here. "Chemistry" needs to come up with something equally as effective, equally as safe, yet not harmful to the environment or equipment.
Have a great day!
Mike
 
I am a bit confused.... as I believed that Halon extinguishers worked by "removing" the Oxygen from the environment, thereby "suffocating" the fire. Not good (ie lethal) if you are a human in an enclosed environment!
 
I always thought halon just reduced the amount of oxygen to a level that would cause the fire to die out, but a human would survive for a short time, although the unconscious body would need to removed from the area pretty rapidly.
 
I used to work in computer rooms in London. We were told " if the fire alarm goes off, you have 15 secs to get to the door, before it locks and the Halon gets activated. You will not leave alive after then" :eek:
 
The Mad Hat Man said:
I used to work in computer rooms in London. We were told " if the fire alarm goes off, you have 15 secs to get to the door, before it locks and the Halon gets activated. You will not leave alive after then" :eek:
Click to expand...
Probably the sort of advice you'd want to pay attention to then :)
 
The Mad Hat Man said:
I used to work in computer rooms in London. We were told " if the fire alarm goes off, you have 15 secs to get to the door, before it locks and the Halon gets activated. You will not leave alive after then" :eek:
Click to expand...

As far as I'm aware, Halon or BCF is one of the "Evapourating liquid" type extinguishers which work buy displacing the oxygen within a space and thereby smothering the fire. The major advantage of this class of extinguishers is that they can store a large volume of vapour by compressing it into a liquid form in a small container.
A major disadvantage is that these evapourating liquids more often than not produce a toxic non-flammable gas.

CO2 is stored as a compressed gas, not as a liquid and would consequently need a larger container for a similar volume of extinguishing gas to BCF, and deploys to a space slightly slower. The deploying nozzles can suffer from icing which can reduce the deployment speed, hence the need for the "horn" arrangement.

Essentially though, you die through shortage of breath whichever extinguisher is used.
 
The Mad Hat Man said:
I am a bit confused.... as I believed that Halon extinguishers worked by "removing" the Oxygen from the environment, thereby "suffocating" the fire. Not good (ie lethal) if you are a human in an enclosed environment!
Click to expand...


You certainly are... Halon has a chemical reaction with the fire, nothing to do with depletion of the oxygen in the area. The concentration of Halon is only 5% of the area volume so you wont suffocate.
Understandably, you have never seen the demo video of the Halon being released in a BT telephone box with a person inside.
 
The Mad Hat Man said:
I used to work in computer rooms in London. We were told " if the fire alarm goes off, you have 15 secs to get to the door, before it locks and the Halon gets activated. You will not leave alive after then" :eek:
Click to expand...
The fire detection system in the computer suite will be installed as a double-knock detection, therefore giving any occupants time to evacuate the area, ie 15-30 seconds to suit, doors don’t re lock, any way unlocking the door to enter the suite will switch the section to manual mode with lamp illuminations to confirm.

Even if the Halon was released, by accident, you won’t want to be any where near due to the deafening noise and the disturbance ie ceiling tiles being dislodged and flying around monitors crashing to the floor etc, hence the first alarm for evacuation. There’s a cctv video showing what happens, no doubt it’s on uTube now

One of my engineers working on a control panel and didn’t isolate the gas and dumped £4000 worth, lucky it was a small system, being a Friday afternoon I had to leave the pub and attend site and what a mess with Halon all over the floor as it does being heavier than air, I left him to clean up after finding him a brush and bucket. That afternoon cost our insurance company just over £12000.
 
Last edited:
The Mad Hat Man said:
Well... the building shook. We left the site an hour later to see all the devastation :(.
Click to expand...
I was coming out of the south bound Blackwell tunnel when I heard the Bang, it shook my car, I thought a container had fallen from a truck behind me. :(

Just had to Google when it was, so 9 February 1996 and I was in my RR then on my way home from Stratford E15.
 
Last edited:
discool said:
You certainly are... Halon has a chemical reaction with the fire, nothing to do with depletion of the oxygen in the area. The concentration of Halon is only 5% of the area volume so you wont suffocate.
Understandably, you have never seen the demo video of the Halon being released in a BT telephone box with a person inside.
Click to expand...
Chemical reaction with a fire?? I would like to hear how that works without Oxygen depletion...
Surely to use 5% by volume, you need to know the volume? A hand held Halon extinguisher, by definition will be used in an unknown volume?

No I haven’t.
 
The Mad Hat Man said:
Chemical reaction with a fire?? I would like to hear how that works without Oxygen depletion...
Surely to use 5% by volume, you need to know the volume? A hand held Halon extinguisher, by definition will be used in an unknown volume?

No I haven’t.
Click to expand...
1. Google if your that interested.
2. Correct, you do need know the area volume, with total flooding Halon or other similar systems, and also for other various reasons.





Sent from my iPad Air on a train
 
The only problem that I can see wit 'Brian 47' siting of his extinguisher is if you have a rear end smash and you cant open the door it becomes very difficult to access.
 
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