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Installing Halon Fire Supression System at Home?

swmagazine asks: "The house my family is building just burn down 2 weeks before competition. Now that the insurance is paying out some money, I am seriously considering installing Halon system at home because the house comes with a server room and I will be having at least 10 computers running in the house. I would like to know if anyone has experience with Halon system as well as the feasibility of installing such system at home." The possibility that your computer could conceivably be a fire hazard is extremely low on newer machines. Older machines, without the proper protection, may overheat, and that might cause problems. Might such a system minimize the damage posed by a house-fire, or are they too expensive (or too ineffective) for the average home owner?

36 of 183 comments (clear)

  1. FM-200 by pci · · Score: 5, Informative

    Well since no one, that I know of, makes ozone depleting Halon anymore, you may want to look at an FM-200 system. I still think this is a bit excessive for home use, most systems I've seen are more than >$10k after purchase and installation.

  2. not halon by Naikrovek · · Score: 4, Informative

    halon is un-breathable. this means that if someone is in the house when the system releases its gas, that that person/animal is dead. it starves the air of oxygen.

    I wouldn't do it.

    the best prevention is to simply watch what the heck is going on with all the electrical stuff in your house and to simply not be careless. sure, all fires aren't preventable, but 99.999% are. Insurance and a good data backup solution will take care of the rest.

    1. Re:not halon by Dahan · · Score: 4, Informative
      halon is un-breathable.

      Depends on what you mean by "un-breathable." It's unbreathable in the same way that nitrogen is unbreathable, but I've managed to survive for a few decades breathing approximately 80% nitrogen/20% oxygen.

      this means that if someone is in the house when the system releases its gas, that that person/animal is dead. it starves the air of oxygen.

      No, that's not true. As the OSHA says, "Not acutely toxic at <10% by volume" and "Generally used at <7% by volume." The National Fire Protection Association agrees, stating that a concentration of 5 percent Halon in air is sufficient for most flame extinguishment. It doesn't work by removing oxygen from the air--CO2 and nitrogen flood systems do that. It works by actively interfering with the chain reaction of a flame.

      As the OSHA site mentions, there are some downsides... breathing 15% or so for a couple of minutes might cause some irregular heartbeats in some people. Also, Halon decomposes into hydrofluoric acid and hydrobromic acid when it's exposed to fire. But then again, it'll put out the fire almost instantly (halon will even stop an explosion in progress)--the minute quantities of HF and HBr are much better than the large quantities of other toxic gasses that burning things put out.

      But the bottom line is that no, you won't die if the Halon system goes off in a room you're in. I've heard that when Halon was first introduced, they'd demo it by putting a guy in a closed room and have him light a cigarette and candle, then dump in the Halon. The cigarette and candle would go out, and the guy would be in there with no ill effects.

    2. Re:not halon by anticypher · · Score: 3, Interesting

      halon is un-breathable.

      Depends on what you mean by "un-breathable."


      I've walked around in a couple of rooms immediately after Halon tests, with no ill side effects. The first time was specifically monitored by pulmonary/blood specialists to detect harmful chemicals entering the body. From what I could determine from reading their raw reports, nothing did. That was a standard 7% Halon discharge.

      The second time was at a company with a really stupid manager who just had to test every part of his new DR plan. In that one the local fire department got involved, so all their firemen could stand around inside and see what occured during a discharge. Walked inside about 20 seconds after the discharge to a room full of white mist, it was a full 10% flood fill test. No side effects from that, except for a pesky hole in the ozone layer which is still following me around today.

      The firemen and doctors both pointed out the nasty effects of HF and HBr on the body, and how long and painful the treatment is. Damage to bone structure is permanent, lungs tend to stay scarred, etc. Which is why if you have a Halon discharge into a room with a big, hot fire, its very wise to hold your breath and do everything you can to get to fresh air. Cleanup crews for several days afterwards will have to wear full protective gear until they can neutralise all the HF.

      However, there is usually enough oxygen in computer room installations, even with a fire, to breathe long enough to get outside. Inside of U.S. military tanks, the Halon concentration is typically 50%-70%, complete overkill but maybe necessary under battle conditions where turning off aircon, power, and engines would lead to a very dead crew very quickly.

      There are quite a few replacements for Halon, none as ruthlessly efficient, but mostly cheaper and all better for the environment.

      the AC

      --
      Hemos is like...sci-fi fans;he thinks technology is cool, but he hasn't bothered to understand the science it's based on
  3. Halon in the home? by TitaniumFox · · Score: 3, Insightful

    Last time I piloted an M1A1 Abrams tank, great stress was placed on the oxygen-displacing effects of the halon fire suppression system. I would have the same concerns about a household halon system that I had in the Abrams. ex. You're in the most central part of your household and the halon system goes off. You're now [however] far from your front door and have what air you had in your lungs. Considerations for what might happen if it went off at night. Kids in the house? Hmmm..

    TiFox

    --
    -- I'd say your post was about 3 monkeys, 18 minutes.
  4. Masks? by poity · · Score: 5, Funny

    Sorry, my knowledge of halon systems comes only from Terminator 2.

    --
    your thin skin doesn't make me a troll
  5. Sprinklers.... by wowbagger · · Score: 4, Insightful

    I have one word for you:

    Sprinklers.

    Actually I have many words for you, but that is the most important.

    You must understand why server rooms use halon rather than water. Remember the fire triad: fuel, oxygen, heat. Rob the fire of any of those and it goes out.

    Halon robs the fire of oxygen. Water robs the fire of heat (and to a lesser extent oxygen).

    Halon is used in server rooms because you don't want the water damage to the servers. Otherwise water is MUCH better at putting a fire out, because you can use LOTS of it.

    Now, if you are building a new house, and you want to reduce the risk of a fire burning it down, put in sprinklers everywhere in the house - it will be a LOT cheaper to set up and maintain than Halon, and it will do a better job.

    Now, if you are going to build a dedicated server room in the house, then maybe you put a halon bottle in it, but not for the whole house.

  6. Uh-oh by GuyMannDude · · Score: 3, Funny

    Dear swmagazine:

    Your recent posting to the underground hacking network "slash-period" regarding Halon has been detected by our information bots. Halon is on the list of 638,931 chemicals maintained by the Ministry of Homeland Security as potentially lethal to Americans. Please report immediately to our facility in Guantonimo Bay for processing while we investigate your interest in this chemical. Do not inform friends and co-workers of your reassignment.

    Sincerely,
    Thomas Ridge
    John Ashcroft

  7. Try Water by fm6 · · Score: 4, Informative
    Right you are. Halon isn't particularly effective anyway. It's only used in machine rooms because it doesn't damage electronics. And even that usage is on the decline. Given the way computers collapse in cost, it doesn't make sense to spend a lot of money protecting them. If you want to protect your data, back it up offsite.

    Consider the ordinary building sprinkler system. There's a reason you can't put up a new public building without one: they're damned effective. But they're also expensive. I don't think I've ever heard of them in a single-family structure.

    1. Re:Try Water by elmegil · · Score: 2, Informative

      From my experience, Halon is in many places illegal; the only places I know that still have it were fitted long ago and are relying on grandfather clauses to save the massive expense of refitting with foam or other types of fire suppressant systems.

      --
      7 November 2006: The day Americans realized corruption and incompetence weren't addressing 11 September 2001
    2. Re:Try Water by Smidge204 · · Score: 2, Interesting

      Or, if you're looking for something that will be a tad bit easier to clean up and will have less collateral damage - why not just a regular ABC Dry chemical (monoammonium phosphate) system? It's fairly cheap, readily available and pretty safe.

      Or what about plain old CO2?

      =Smidge=

    3. Re:Try Water by fm6 · · Score: 2, Interesting
      I stand corrected. A little Googling turns up an active movement to require sprinklers in homes. And that's a very good idea. The stats on fatalities in sprinklered versus non-sprinklered buildings are mind-boggling.

      I was wrong about the cost too. It's something like $4 per square foot. OK, that's thousands for a medium-sized home. But considering the cost of a home, and the possible benefits...

    4. Re:Try Water by Maclir · · Score: 3, Insightful
      I have done a number of commercial computer room installs. The process is:
      1. Have the sprinkler system integrated into the electical and a/c.
      2. As soon as sprinkler head pops, flow detectors on the sprinkler pipes detect it, set off an alarm and kill the electrical power.
      3. A/C dies - we dont want something pumping in fresh air.
      4. If you have a UPS - kill power on both sides of the UPS.
      5. Generally, except for the equipment that started the fire, everything will work once you dry it out.
  8. Inergen, not halon... by Shoten · · Score: 3, Informative

    Ok, you can no longer (I'm assuming you're in the USA) get halon, as it is harmful to the ozone layer. What's now used for this purpose is called Inergen. Furthermore, despite all the howling by everyone about the risk of suffocation, keep in mind that it will take a bit of time for an entire home to become filled with the stuff, and the fact that any professionally installed system includes alerts to let you know when the system is activated. Between the warning you get, the air in your lungs and the air that has not been displaced yet, you can be just fine. This kind of system has been put in many types of facilities in all sorts of different ways, and unless it's done incredibly wrong, by no means will it turn your home into a big gas chamber :)

    --

    For your security, this post has been encrypted with ROT-13, twice.
  9. P.S. by GuyMannDude · · Score: 2, Funny

    P.S.: Upon your arrival at our Guantonimo Bay processing center you will be required to provide five (5) forms of identification. You must also provide them with your assigned processing identification code. Your identification code is

    swmag_4638391_chemweap_983

    Failure to provide this information upon check-in will extend the duration of your processing by approximately 6-18 months.

  10. Treat the cause not the symptoms by Ratso+Baggins · · Score: 4, Insightful
    Forget fire control for a moment, you have a construction material and/or site layout/placement problems.

    If you are building in a fire prone area consider partially or majorly covering the building in earth. (A side benefit is your heating energy provider will hate you.) If the fire was an "accident" then you most definetly have a materials problem. Wood, while very attractive and cheap to buy & work with, is fuel. eg: Would you use compressed "fire retarded" straw or paper as a building material? (I wouldn't) It is supposed to be more fire-resistant than wood.!?

    Consider naturally inert and fire resistant materials like concrete & bricks.

    Then high risk/expense/maintainance fire suppression systems like halon become pointless. Ordinary smoke detectors can then be sufficient.

    Using halon is such overkill and may even accidentally kill one of you loved ones. It's like having loaded 9mm handguns at convienent, accessable places around the (wood & paper) house to combat a roach problem when all you had to do was clean up your filth.

    --

    --
    "we live in a post-ideological world..." - Billy Bragg.

  11. Halon health considerations by shadowbearer · · Score: 2, Informative

    http://www.healthsafetyinfo.com/news/tip/autotip-a rc.cfm?content_id=11890

    --
    It's old. The more humans I meet, the more I like my cats. At least they are honest.
  12. Re:et ego by PD · · Score: 2, Interesting

    That's really a brilliant idea, and it would be fairly cheap to do. Or you could make a special closet. The entire server closet could be made from cinder blocks, including the floor and ceiling. Put a fireproof door on it, make a rule that only computers (no paper or anything flammable) goes in the server closet. Should be about as safe and cheap as anything for the home. It could even be build in a corner of a garage.

  13. Fire Retardation by NanoGator · · Score: 3, Funny

    Okay dudes, I got a buck that says his machines are all Athlons.

    --
    "Derp de derp."
  14. wha? by resignator · · Score: 4, Funny

    Halon is perfectly breathable. As a matter of fact, I'm huffing some at this verrrrrrrrrrrrrrrrrrrrrrsadfffaa

    --
    "At first, we thought it was just another snake cult."
  15. Check your local fire and residential codes. by muonzoo · · Score: 4, Informative

    In a great many jurisdictions, Halon systems are not permitted in personal residences. They are a hazard to life and limb. The old server rooms we protected with Halon systems required 'life support' equipment in case you were in the server room when the system discharged.

    Halon displaces the oxygen in the environment it is released into. This is NOT something you want to be doing in your house without sufficient research, and compliance with ALL local ordinances. Failure to do this could jeopardize you and your family. However, I'm sure your machines would survive.

    Your insurance company would likely be less than thrilled at the prospect of you having an automated mechanism for discharging a gas that can asphyxiate you and yours.

    1. Re:Check your local fire and residential codes. by Gudlyf · · Score: 4, Insightful
      The old server rooms we protected with Halon systems required 'life support' equipment in case you were in the server room when the system discharged.

      I can attest to this fact myself. At my employer's old building, there was a Halon system still in place. As far as I know, it was still useable by some sort of grandfather clause or some-such, but that's not the point.

      If a fire broke out in the server room, first a very bright red light would turn on in the room, followed by rapid beeping -- this is phase one of the warning, which you had about 15 seconds to heed until the next phase.

      After 15 seconds of THAT warning, a ear-piercing alarm would sound off in the room, and I mean ear-piercingly loud and high-pitched. A light would also turn on over the door to the server room with a sign reading "DO NOT ENTER -- HALON IN USE" near it. That's phase two.

      At phase three, if you're still in the room, you're either now burning to death or suffocating, or both.

      Sorry, but this has to be said... I realize that there are a lot of geeks/nerds reading this site who just love to play with the newest/oldest technology, either because it's cool, retro or hip, or because they want to actually learn something by doing. When I read an Ask Slashdot like this, I can only imagine the poster doesn't have their head screwed on straight and may be thinking this is the hip/cool thing they can install in their home server-room (home server room with ten systems?! WTF?!), and maybe call it a conversation piece here on Slashdot the next time someone brings up insane home setups. The fact that Halon was brought up -- something several people already pointed out as illegal and harmful to use -- just shows that this just seems like some Wahoo who did zero research into such a dangerous project.

      Anyway, after that bit of Trollbaiting, I understand that a catastrophic event has happened with your original home, but please just remember that something like Halon is made to protect computer equipment. Use something that will protect people, for Godsakes.

      --
      Trolls lurk everywhere. Mod them down.
    2. Re:Check your local fire and residential codes. by dattaway · · Score: 2, Funny

      I learned about halon fire systems from the BFOH. He describes their utility to the full potential.

    3. Re:Check your local fire and residential codes. by JayBat · · Score: 2, Interesting
      > The old server rooms we protected with Halon systems required 'life support'
      > equipment in case you were in the server room when the system discharged.

      I can attest to this fact myself.

      Oh, nonsense. This is clueless, not insightful.

      If a fire broke out in the server room, first a very bright red light would turn on in the room, followed by rapid beeping

      Main reason for this is so you can abort the discharge in the event of false alarm. Every halon system I've ever been around (three of 'em) has had at least one false discharge in it's life.

      After 15 seconds of THAT warning, a ear-piercing alarm would sound off in the room, and I mean ear-piercingly loud and high-pitched. A light would also turn on over the door to the server room with a sign reading "DO NOT ENTER -- HALON IN USE" near it. That's phase two.

      That's because if you open the door, you let the halon out and provide fresh oxygen to a (presumably) active fire, not because the halon is dangerous. Jeez.

      At phase three, if you're still in the room, you're either now burning to death or suffocating, or both.

      Well, if you're standing around in a burning room, you're a moron, but if you're suffocating, it's not because of a 10% halon concentration. I have stood in the middle of a computer room during an inadvertent halon discharge (maintenance guy screwed up during the annual system test), and it's a total non-event (except for being very loud, and every single loose dust particle and piece of paper in the room flying around!).

  16. Let the Servers Burn!!! by jayrtfm · · Score: 2, Insightful

    You've got insurance? Then let em burn, cause a computer safe fire surpression system will cost more than the computers.
    But the *DATA* is important to save. I'm guessing that since you're building a house, you've got a backyard. Why not build a seperate little shack for a server or two as an off site backup?

  17. Yeah, Halon by the+eric+conspiracy · · Score: 4, Informative

    I love it.

    Halon is -

    A trade name for a class of halogenated alkanes. Other trade names for these materials are Freon and Genetron. It is one of the classes of materials that has been proven to attack the ozone layer, with persistance in the atmosphere measured it decades. Manufacture of many types of Halon was banned by the Montreal protocol in 1987. Further legal restrictions were subject of the later Kyoto protocol.

    The particular Halons used in fire extinguishment applications are 1301 and 1211. As of Jan 1 2003 refilling existing halon systems is banned in most of the world, and dismantling of all Halon fire extinguishing systems (including safe disposal of their contents) is required by Dec 31 2003.

    Halon works by displacing the natural atmosphere in a room, reducing the concentration of oxygen to levels below that which will support combustion. Since the human body metabolizes sugars to sustain life by a controlled form of combustion, human metabolism will cease under the same conditions.

    Halon, when exposed to fire or similar high temperature conditions will decompose into a variety of toxic gases that will generally cause traumas such as pulmanory edema.

    It is illegal to install new Halon systems except in certain 'Critical' applications, mostly in aircraft fire supression systems.

    For home applications involving electrical systems a good ABC fire extinguisher containing a dry chemical like monoammonium phosphate available at your local hardware store is the best choice. Use of fire resistant materials, elimination of clutter and especially adherance to electrical codes in your server room are also recommended to prevent fires in the first place.

    Your most important fire control steps are prevention.

  18. Resedential sprinklers are NOT expensive by A+nonymous+Coward · · Score: 4, Informative

    I was quoted $1.25 per sq ft several years ago. Even if prices have gone up to $2 sq ft, that's only 1 or 2 percent of the total cost. Pretty cheap for good protection.

    Also, the very fact that you are thinking of Halon implies you want to put the fire out and preserve everything. That's a nice goal, but computers are cheap and easily replaced, and presumably you have offsite backup storage.

    The point of fire protection is to give occupants time to get out and to stop the fire from spreading. Saving the structure itself is a nice side benefit. Saving minor contents is pure gravy.

    1. Re:Resedential sprinklers are NOT expensive by fm6 · · Score: 2, Informative
      You're right (and I was wrong) about the cost. But sprinkler advocates seem to consider sprinkers to be very effective at preserving structure and contents. The thing is that most fires start small and grow quickly. But if you have sprinklers, even a small fire will set off 3 or 4 heads, and that'll limit fire and water damage to the area around those heads. Compare that to waiting for the fire department to come -- even if they save the structure, water damage is likely to ruin the contents.

      So I guess there's no really good reason sprinklers aren't in every new structure in the U.S. I'd guess that the only resistance comes from building developers, who see even a marginal increase in costs coming out of their bottom line.

      In the (unlikely) event I ever build a house, you can believe it'll be sprinklered!

  19. Halons do NOT primarily work by O2 Displacement by bigsteve@dstc · · Score: 2, Informative
    ... according to this quote from the H3R website.
    Halon is a liquefied, compressed gas that stops the spread of fire by chemically disrupting combustion. Halon 1211 (a liquid streaming agent) and Halon 1301 (a gaseous flooding agent) leave no residue and are remarkably safe for human exposure. Halon is most effective for flammable liquids and electrical fires (rated B:C) and is electrically non-conductive.

    Actually, this is common sense. If you wanted to damp combustion by excluding oxygen, it would be cheaper (and more environmentally friendly) to use an inert gas like nitrogen or carbon dioxide.

    There is no doubt that Halon does replace oxygen to some degree and therefore does present a potential danger of asphyxia. However, there is another problem with Halons. When they come into contact with a fire, they breaks down, releasing breakdown products that are extremely dangerous, even at low concentrations.

    1. Re:Halons do NOT primarily work by O2 Displacement by Dahan · · Score: 3, Informative
      Right... I don't know why everyone likes to say that Halon fire supression systems will kill you if you're in the room, or that they work by removing oxygen. It's reached urban legend status...

      There is no doubt that Halon does replace oxygen to some degree and therefore does present a potential danger of asphyxia.

      A 7% concentration of Halon 1301 will put out a fire... that leaves plenty of oxygen for breathing. Sure, you'll have problems if you flood the room with the 50% or so that an inert gas like CO2 requires (up to 75% CO2 for dust fires), but Halon is/was expensive--there's no point in releasing that much Halon.

      Halon is banned due to it being an ozone-depleting fluorocarbon, not due to it being a health hazard. BTW, Halon 1301 means 1 Carbon, 3 Fluorine, 0 Chlorine, 1 Bromine--CF3Br.

  20. ABC and CO2 by fm6 · · Score: 2, Interesting
    Yeah, I saw some of those in a hardware store, considered the price, and decided it would be stupid not to have a bunch on hand. But:

    They're only useful if you're around to use them, and use them quickly. I think the rule is that if you don't catch a fire within three minutes of it starting, you should get the fuck out and call the fire department. Those suckers spread fast.

    They're only got for 3 or 4 years, then you have to replace them. Come to think of it, all mine probably need replacing!

  21. A question by Tuxinatorium · · Score: 2, Informative

    "The house my family is building just burn down 2 weeks before competition." Was that before or after completion?

  22. It's Argonite you probably want, not Halon by forged · · Score: 3, Informative
    Argonite is installed in the labs hosted at my employeer's, I think it's illegal now to use Halon 1301.

    Search Google for Argonite and you will find such great links as this one. Transcript below for the clicking-impaired or just lazy :-)

    Argonite - fighting fires nature's way
    More and more companies are today ensuring that environmental considerations play a major part when selecting a fire fighting system. So much so that Argonite, which consists entirely of naturally occurring gasses, has long been the solution of first choice for many industrial and commercial building occupiers.

    Not only has Argonite zero Ozone Depleting Potential (ODP), it also contributes nothing towards global warming, thanks to a complete absence of hydrofluorocarbons-HFCs. At the same it is a gaseous fire suppressant that has an enviable 50-year track record.

    The environmental answer:
    Argonite is a leading environmentally-friendly replacement for Halon 1301. An equal blend of nitrogen and argon, it produces no secondary combustion products and is particularly suitable for fighting fires in confined spaces. Because its molecular weight is close to that of air, it lingers longer when discharged to extinguish a fire. This reduces the need for hermetic sealing of a protected room - a process that can be very expensive and needs to be repeated every time structural changes are made.

    Argonite is not prone to fogging, is non-toxic, non-corrosive, leaves no residue and is electrically non-conductive. This has led to it being successfully specified in applications where there is a need to avoid secondary damage by the fire fighting agent. Popular applications include computer and control rooms, tape and archive stores, electrical cabinets and switchgear compartments and around telecommunications equipment.

    How Argonite Works
    Should a fire start, Argonite is injected rapidly into the room, reducing the oxygen level from the normal 21% to between 11% and 13%. This is too low for further combustion to take place, yet high enough to allow essential safety personnel to operate.

    Argonite is suited to either total flooding or local application. When more than a single room or compartment is protected, GIELLE normally recommends that a central bank of Argonite cylinders is connected via diverter valves. This frequently proves to be the most cost effective and efficient solution. As a permanent gas working under high pressure with single-phase flow characteristics, complicated pipe networks can be installed.

  23. Build an escape pod instead by smoon · · Score: 3, Funny

    Rather than screw around with chemicals, making the server area airtight, etc. a much better solution is to bolt all of the computers into a spring-loaded rack instead.

    When fire is detected you could have some conventional CO2 fill the server cabinet for 1-2 minutes while your UPS software does a 'safe' shutdown of all equipment. Then either a large CO2 blast or strong spring or possibly an explosive charge launches the equipment rack through a hatch out into the yard -- safely away from the burning house.

    Make sure to mark the area well so firefighters, family members, etc. don't stand in the way, and also make sure to not point it at the pool -- wouldn't that be ironic?

    --
    "But actually trying to use m4 as a general-purpose langage would be deeply perverse" --ESR
  24. Halon health risks by BobBoring · · Score: 3, Informative

    Halon is bad for the ozone layer was the reason given for its going out of use in the US. They have found out recently that it is not as bad as they though so it is starting to come back.

    Being exposed to Halon is not a big deal. The OSHA exposure standard is based on exposure to Halon in a neutral environment. Being in the room with a halide gas and a large fire is the problem.

    The major health risk with Halon dump extinguishers is the by products of the quenching cycle. The way halides interfere with combustion is an ionic cycle that sucks the energy out of the combustion process. The cycle is a true cycle and depends on the halides eventually returning to their original state. During the cycle you get other unstable intermediate products that are not toxic per say. They are ionicly unstable and will rip atoms out of stable molecules to get to a stable state. The hotter the fire the more of the intermediate products produce and the longer they hang around. Additionally the cycle is not 100% closed. The combustion products from the plastics in computers plus the halide gases make some bad stuff(TM) like phosgene for example.

    A small fire goes out quickly, typically >30 seconds and produce little in the way of toxic by products. A big fire goes out more slowly, 3-5 minutes. Because larger fire is hotter and takes so much more time to quench, far more of the toxic by products are produced. Breathing the larger quantities of the intermediate products created by a larger fire plus toxic gas produced by the fire can cause irreparable harm to you lungs. Getting out of the room quickly is to avoid exposure to the smoke and letting the Halon do its job.

    The SOP for Halon dumps was: you pull the handle the electric primary power to the room disconnects, a horn sounds, a short time, seconds, later the Halon floods the room. The delay is to let everyone leave before the flood starts. Once the fire is out and the Halon and combustion site has a chance to cool off you only have to worry about the toxic smoke from the fire. I've seen people open the door to soon after a fire, let too much of the Halon escape and have the fire rekindle.

  25. Ounce of prevention vs. pound of cure? by JonTurner · · Score: 2, Insightful

    >>ozone depleting Halon

    That's just knee-jerk enviromental scaremongering. What has a greater enviromental impact:
    1) a Halon discharge which prevents a fire, or
    2) a house burning to the ground?

    Yep, that's what I thought. If you doubt #2 is the correct answer might I suggest that sometime, just for fun, you ask an environmental engineer about the remarkable volume of nasty chemicals, soot and particulates released as a result of burning carpets, padding, insulation, paint and misc. plastics which make up a modern home? That should remove any doubts.

    But let's assume for one moment (contrary to scientific evidence) that Halon truly is damaging to the environment. What do you rekon happens to the refrigerant in the air conditioning system when a home burns down? Yes, that's right, it's vented straight into the atmosphere. Well, if you accept the enviro-nazi poposition that Halon is damaging then surely one must also accept the idea that air conditioning refrigerant also damages the ozone layer. So what's worse? A Halon discharge or a big nasty housefire AND a refrigerant gas discharge?

    Finally, consider that in many states pressure-treated wood is considered toxic for purposes of disposal, requires special handling, and cannot be placed in a landfill. Burning it simply releases those toxins into the air. SO when that deck goes up in flames, it releases mercury, arsenic, and a host of other nasties.

    The real risk of a Halon system not environmental -- the risk is *suffocation* due to an accidental discharge. Halon, being an invisible, odorless gas, will choke the life out of the homeowner nearly as well as it chokes out a fire. It's a system which requires regular professional inspection, testing and maintenance.