Halon in a residence
 

We've had a few fires around here lately, and I'm not sure if it's just our incompetent local firemen or whether it's generally true, but even if you have a somewhat minor fire, their best answer is to tear your house apart and spray water for a couple hours - it's rare that the damage they do is much better than just having let the house burn to the ground.

So, it got me thinking - if you have any kind of major fire, the only effect of spraying water is to keep the fire from spreading, not to put out the fire (and sometimes it doesn't work to keep it from spreading!). I figured there has to be a better way to extinguish fires, and a lot of comouter data centers use halon.

I expect that halon is expensive, but I was wondering how expensive? Also, is there any maintenance, as in do you have to refill halon every few years, etc.? Would is be feasible in a residential installation? Heck, you'd think releasing a sufficient amount of carbon dioxide should be enough to quell most fires.

Not sure about the effectiveness in a home.

Halon works well in data centers because data centers tend to be closed off environments with a relatively fixed internal volume so the proper mix of Halon to extinguish and prevent re-ignition can be easily determined.

My super uneducated opinion:

I think halon displaces air thus if it went off in a house everyone inside would suffocate.

Edit to add... I see you also consider using carbon dioxide so apparently you are not concerned with the occupants.

Pretty much my thought, displaces/removes the oxygen, so pretty much not a great idea for homes. Probably why they're not pushed for home use. Maybe have many large fire extinguishers around??

I have a sprinkler system in my townhouse in VA, I always worry if the darn things go off...love/hate....stops fire, but ruins everything else. Ah, just like your local firemen.

No. That is Carbon Dioxide. Halon doesn't suffocate. But it has other problems, related to long term exposure.

In my debates on it, you have something that will kill you NOW vs. somthing that *might* hurt you genetically later vs. being burned alive.

I build telephone switches and have installed a large number of these systems. Halon is being replaced by other gases but the systems are similar.

No, you can't afford it.
Your house likely isn't sealed well enough to use such a system.
It wouldn't be easy to retrofit into an existing house, if you want to hide the components.
No maintenance, really, apart from checking its integrity from time to time.
There are fires that occur in houses that wouldn't be well covered by such a system. Attic fires come to mind.
You really wouldn't want to be in the house if it went off.
The gas itself wouldn't make a mess but it would definitely stir one up, what with the dust and loose items that exist in your house.

A hand-held extinguisher is probably a good idea, for the kitchen, garage, etc.

JR

reposted for emphasis (with a few mods)

Nobody is using halon anymore - if you're in an area with a halon system and it goes off, you either get out immediately, find and don a respirator/supplemental O2 immediately, or you die.

The new "clean agent" type systems are argon-based and will not kill you if you find yourself in a space that happens to have one when it goes off.

Usually there are countdown alarms with either type of system based on multiple detections (i.e. two or more smoke detectors) or a pull station will blow the bottles immediately with no countdown. Either one is considerably more expensive than a typical water-based system and must be checked/maintained on regular intervals.

You can use a pre-action system if you're concerned about someone whacking a sprinkler head and ruining your house. With those, a "first alarm" (first smoke detector or heat detector) will run a pump to charge the (normally empty) pipes. Then if there's enough heat to pop the head, water will flow. This is a much safer type of installation where inadvertent damage to property is a consideration.

With any type of residential sprinkler system you should be able to negotiate a much better rate on your homeowner's insurance. And municipalities are starting to lean towards requiring these for new residential construction (even single-family detached in some areas).

It's worth looking into. For starters, check NFPA and/or consult a professional (yes, I know that's a little self-serving, but really - they can point you to a lot of good information).

EDIT: Just saw javadog's post and pretty much agree with it. With gas suppression systems you need a pretty well-sealed environment (you'll need an engineer to do a pressure test to make sure the agent won't just disperse and will remain in sufficient concentration in the space to snuff out the fire). You certainly can tighten up your envelope in order to get the proper seals but it won't be cheap.

I'm envisioning a solution that involves a swimming pool on the roof.......

My brother in law installs these ^ systems. For the fire marshal test they walk into the room, discharge the system, and try to light matches. The matches don't burn, system passes.

It lowers the oxygen percentage enough that the fire can't burn, but it's not dangerous like halon (which isn't used anymore).

He does do some residential stuff, but it's more like a system for a datacenter or studio within a home, not the whole home. The systems are designed for a finite confined space. I guess you could make that space your whole house but since houses aren't really sealed between rooms it would have to displace oxygen in the entire house at once if there was a fire anywhere. An open door or window would make it ineffective. The system couldn't protect from a fire on the exterior of the house (catching from a tree or neighbor's house).

So you'd have an expensive system with limited effectiveness, but yes it could be done.

[QUOTE= You certainly can tighten up your envelope in order to get the proper seals but it won't be cheap.[/QUOTE]

Nor would it be healthy ... some air exchange is a good thing...

The halon dumped at a switch I was working at once. No one died and some of them were in there for a while.

I think its no longer legal though... ozone depltion or something.

it's been replaced with Halotron

that Argon system sounds like a great way to end an-overlong party! Pull the switch, then just drag them all outside...

I've never seen a fire marshall do that. The gas is way to expensive for discharging, just to test it. The systems are engineered very carefully to establish the quantity of gas needed, the alarms and solenoids are checked for proper operation while NOT attached to the gas bottles, and a fan test is done to check the room integrity.

Dumping the gas in one of my typical systems would generate a 6-figure bill to replace it.

JR

I was thinking more in the situation where you were outside the house before it went off, thus carbon dioxide, but it sounds like I'd either have to use a lot of carbon dioxide or have my house well sealed.

Thanks for the comments.

We used CO2 on the Gas Turbines. Some of the Factory Mutual inspectors liked a concentration test! This meant dumping almost 3000 lbs of CO2 into the Gas Turbine compartments! Usually I could talk them into a function test using just 2 bottles. I would dump the first one to clean the lines, then reinstall the horns and dump bottle #2. A lot less dangerous as well, since CO2 smothers.

They all push the O2 level from 20.8% to around 19.5%. Very, very expensive systems. Others are right, Halon is no longer allowed in new systems. Ozone depleting. You can breathe very high levels of CO2, its the O2 you can't live without.

We still use Halon on the submarines, very effective especially when the FD are 100s miles ashore.

The tanks are pretty big too. The last one I was involved with was a 1500 sq. ft. computer room (forget the volume offhand but it was a typical 12-ish foot ceiling, nothing ridiculous or double-height or anything) - two huge 500# tanks of agent - a primary and a standby. And the tanks are heavy (need structure or a pad, need seismic restraint, etc.) It all costs $$$.