Just got to wondering —
I’ve never heard of anyone living in a high fire danger area (like many areas of California) having a “fire shelter” built into their home, kind of like a tornado shelter in the plains states, or a bomb shelter.
Do such things exist?
If your view never changes you’re following the wrong leader
Replies
Never have heard of one, but it's an interestign idea.
I suppose the biggest limitation would be keeping a source of oxygen available for an extended period of time.
I'd think you'd just need smoke filters, and the ability to shut off air in/out during the hottest part of a fire.
If your view never changes you're following the wrong leader
CO2 is heavier than air, so it would settle into low places such as an underground shelter. So filters wouldn't do any good. Air that was pulled in as your house burned down around you would also be incredibly hot. So again, I don't think the idea of filters is viable. compressed air or oxygen would likely work well, as long as you didn't get a leak. If you had an oxygen leak during a fire it could be like the astronauts that burned on the launch pad way back when. Not something you would want to happen to your family.
Doesn't expecting the unexpected make the unexpected expected?
I'm thinking of the bomb shelters used during WWII. Many were designed to survive a firestorm. There would be enough oxygen in the shelter to allow a small number of occupants to survive for a couple of hours, and in most cases a firestorm blows over in minutes.
If your view never changes you're following the wrong leader
designed to survive a firestorm
The trick is in the physics, is what comes to my mind.
Probably a waterjacket would be needed--which might not be a bad deal, you jsut don't want to drain it down before jumping in the bolthole. So, it would probably ought to be only an irrigation storage tank.
Open area fire like that will run between 1500 & 1800º; true 'firestorm' will also generate 50-60mph winds, too. That's not very nice conditions for operating air filters "in." CO2 not so bad, draw incoming air over potash, and you're pretty good. The CO, though, will be a hassle. Probably need some form of "flushable" particulate filter, too (inverted "U" with the particulate filter stack rigged so that a "push" of air will let gravity do the rest).Occupational hazard of my occupation not being around (sorry Bubba)
But the type of fire they're having blows through in 15 minutes, and often the brush near the ground isn't even completely burned. Yeah, it's intense while it lasts, but think about all the firewall structures that have a 30 minute rating -- they should "in theory" be sufficient (though I'd certainly want something a little more solid). In fact, a hole in the ground would likely suffice.Re air/smoke/CO, keep in mind that the fire is drawing air and all the combustion products upward, with (relatively) fresh air entering at the bottom. It would only be during the most intense part of the fire that you'd really need to do anything, and simply stopping air circulation should suffice. The average human breathes 15-20 cu ft per hour, and can of course rebreathe the same air several times without harm. A 5x10x8 room is 400 cu ft, or at least 20 person-hours of air.
If your view never changes you're following the wrong leader
Re air/smoke/CO, keep in mind that the fire is drawing air and all the combustion products upward, with (relatively) fresh air entering at the bottom. It would only be during the most intense part of the fire that you'd really need to do anything
No, I'm with you there on that, I'm just, kinda, positing ahead to an in-the-house bolthole. Actual firefront might be brief, but it could take time for a person's house to burn down over their shelter.
Now, you may be on to something in just "turtling up" in the shelter, sealing up and waiting for the front to pass. Just got back a "wait a minute" answer to my firestorm physics q, but, you might be able to use the air change itself to seal up the ventilation (doors, I've not worked out yet).
See, the thing to remember is that the front of the firestorm is a contrast, it's a pressure wave and a pressure drop at the same time. You get a 'bubble' of superheated air pushed out in front, but the combustion/chimney effect is vaccuming atmoshere away as it passes over you. So, I'm brainstorming an idea to use the overpressure (maybe plus a fusable link) to slam the vents shut, then hold them that way until after people can breathe again. It's an intriging idea, really.
Hmm, just had a thought--drill some air-to-air heat exchange ground tubes under the fire shelter. "Pay" for them with a connection to the hvac for the house, but, keep them as a reservoir of sorts of "potable" air. Ductwiork and dampers might be a pain though. Dang it, I need numbers--some of the post-Dreseden stuff suggested needing "tightness" to 1.5 or 1.75 Bar, which is a lot of bends to put in one's fresh air intake (the opposite of what we normally want in an exhaust fan, say). And, doors, dang it. Probably need three, in a S-bend 'airlock' to seal right.
Tornadoes sure are simpler <sigh>Occupational hazard of my occupation not being around (sorry Bubba)
Yeah, I think your main hazards are:1) The house falling down on top of you and either crushing you or trapping you in the hole.2) The fire from the burning house lasting significantly longer than the front of the firestorm.Certainly #1 can be handled by sufficiently reenforcing the structure (wouldn't take much to make, say, a 5x10 CMU room secure from the collapse of a standard frame home), and by siting it reasonably well (eg, have the entrance outside or via a scuttle hole in a porch or sunroom floor). Also, it wouldn't be unreasonable to have a "back door" that requires breaking something to use. Eg, you'd open a hatch and then smash though a light stucco wall to get out.#2 can be partly handled by siting as well, though it's certainly in the "requires thought" realm. I don't think that air sealing would need to be especially pressure-resistant, though it would be wise to go through some calculations to make sure that the whole structure wouldn't be likely to burst open from air pressure in worst case fire-induced vacuum.
If your view never changes you're following the wrong leader
though it would be wise to go through some calculations to make sure that the whole structure wouldn't be likely to burst open from air pressure in worst case fire-induced vacuum
And, it's wierd stuff (only vaguely remembered by me, too). As I remember from Passive Protection, (one of the tomes about the house), the thing is the Delta-P; the firefront rolls through a couple-three hundred positive mB to have the updraft be 3-400mB the other way. That gives you the 'fun' of design that needs to withstand 6-800mB of change over a very short interval (that's spanking close to an Atmosphere of DeltaP). I do remember that you want either two or three "S" bends in both intake and exhaust ductwork, with operable dampers.
The present building construction "thing" is in doors. The average door is probably 'good' for 250-300mB; a "wind rated" door probably 300-400mB--the trick of that is at what "bleed" rate at what temperature. I'd rather not be huddled in the shelter to find out that the shelter door was good for another 50-60mph of firefront wind, just not at 1250ºF (or, that it was only "leaking" fractional cfm of external "wind" 'cooled' to a mild 750-850ºF . . . )
Back to tornadoes and hurricanes being much simpler. You door holds up, maybe leaks a few mL/hr in 115+ winds, that's not that critical a problem. Melting the magnetic seals to the door frames . . .
Technology is there, though, I'm thinking. It might even be a practical rehab/renovation item--just can't fail in use.Occupational hazard of my occupation not being around (sorry Bubba)
It occurs to me that most of the barometric concerns could be handled with a double room. Probably you'd build the CMU room and then inside it a drywall room, both reasonably tight but not pressure-tight. (In fact, you might build barometric vents into each wall, positioned as far from each other as possible.) If the volume of the outer room (after subtacting the volume of the inner room) was about half the volume of the inner room then very little smoke/heat from outside would make it into the inner room. The space between could even be loosely filled with FG insulation to serve as a sort of filter, in addition to providing additional fire protection.
If your view never changes you're following the wrong leader
It occurs to me that most of the barometric concerns could be handled with a double room
Yeah, that's probably an elegant sort of answer--if potentially fraught with difficulties in the ugly real world of remodelling <g>.
Probably where the stick-shelter-in-tank-of-water idea cropped up from, too. Which could be nice for having a supply of fire-fighting water "on hand" for when you crack the shelter door open . . . Occupational hazard of my occupation not being around (sorry Bubba)
The thing is, you sell this beast as a wine cellar or some such. The same basic specs would suit both uses. Plus if things start to look bleak at least you can go out in style.
If your view never changes you're following the wrong leader
I ran a fire crew for nearly 10 years back in college and there is a well designed fire shelter that any wildland firefighter would use if they knew you had one as part of your property.
It's called an open space free of brush or trees or better yet a big lawn. Crews will sit out a fire, protecting the house as need and let the fire burn around a good defensible space.
If the house is built so embers can't start the structure on fire a fire break around the house is the number one thing that will keep your house in one piece.
I look at many of the houses that are burning in California and cringe. Ask any California firefigher with experience on these fires and they'll tell you how easy it is to predict which houses will burn and which don't.
Cheers!
Beer was created so carpenters wouldn't rule the world.
http://wildfirenews.com/fire/articles/ted.html
http://www.fs.fed.us/fire/safety/shelter/shelter_index.html
http://www.monolithic.com/domenews/2006/okfire.html
http://www.monolithic.com/gallery/homes/braswell_fire/index.html
Dan is talking about shelters built into conventional houses. Not portable shelters used by smoke jumpers or dome homes.
Computers can never replace human stupidity.
Yeah, and the shelter could incorporate another feature, such as a storage area or even small home theatre. The traditional plains tornado shelter doubled as a root cellar.
If your view never changes you're following the wrong leader
Dan, if it's true that this thread is only open to discussion of fire shelters fully enclosed within homes made of kindling, let me know and I'll remove mention of anything else that might be germane but doesn't fit those limitations. I certainly don't want to offend anyone by considering all possibilities of materials and approaches.
Not really limited. I was aware of the tent-like fire shelters, and they would seem to suggest that a permanent one wouldn't need to be high-tech.
If your view never changes you're following the wrong leader
all is a good idea but then the lawyer get involved and start talking about liberility so the government just say no and just leave.reason why. ten years ago, during a hurricane the sherriff so find some place safe and hunker down. now its everybody leave town no matter what, the storms are not stronger, its liability, your going die, your going die, your going die..Know BOB, Know Peace
A hurricane is somewhat different. It's kinda tricky to build a flood shelter.
If your view never changes you're following the wrong leader
A flood shelter is called a "boat"Rebuilding my home in Cypress, CA
Also a CRX fanatic!
If your hair looks funny, it's because God likes to scratch his nuts. You nut, you.
you think when you get hit by an hurricane everything floods, only about the first 1/2 miles from the gulf, but you still have a couple hundred miles of land with wind over 100 mph. Laurel Ms wasnt by the coast and alot here seen the damage there..Know BOB, Know Peace
Even 50 miles inland flooding is fairly common, due to the rain. And most of the deaths occur within maybe 5 miles of the coast.
If your view never changes you're following the wrong leader
Some implications of the tent shelters described in the first link are that people weren't dying of o2 deprivation. They were dying of burns or too much heat. The temp shelters were protecting them till the fire raced past. Implication is you don't want to be in a building that will burn around and under you for additional hours. I'd take that temp shelter and put it in the middle of the lawn till the worst passed rather than stay in a smoldering house with the toxins of whatever plastics and such were burning inside.Alternatively, I'd stay in a high mass house built that could handle the heat for a reasonable duration without itself combusting.Best is to leave, but this is in case you're caught without escape route.
I remember reading some where there was a trend in the direction of using noncombustible materials on the exterior of houses.
Terra cotta roofs, or steel roofing, brick or cement siding the idea of the article was to not let the building catch on fire to begin with.
They were also suggesting a burn free zone around the house, vegatation and other combustibles were to be kept away from the house.
Sounded like it might work but it would require regular maintenence.
I have perhaps a silly question,which way should a door open on a fire shelter, I would out would be logical but it could be blocked. and which direction would it face.
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., wer ist jetzt der Idiot ?
Not a silly question -- same issue arises for tornado and bomb shelters. I think inward is probably best, but with sturdy latches.
If your view never changes you're following the wrong leader
that seems to make the most sense,
but have not been through a firestorm...yet.
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., wer ist jetzt der Idiot ?
Don't ferget the little winders so's you can poke yer weenies out on a stick and get'em nice and crispy...bun warmer too...
I wonder about that with hurricane shelter, why don't people accept personnel responsibility
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Know BOB, Know Peace
Edited 10/23/2007 1:29 pm by brownbagg
"personnel responsibility"there is no such thing in the US, it is the only illegal thing that people won't do.
bobl Volo, non valeo
Baloney detecter WFR
"But when you're a kibbutzer and have no responsibility to decide the facts and apply the law, you can reach any conclusion you want because it doesn't matter." SHG
Sort of like a built-in convection oven?
That's what I was thinking. I'd build a freaking escape pod. Get in it when the fire gets close. Set the direction away from the fire and take off.
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"I tell you, We are here on earth to fart around, and don't let anybody tell you any different." Kurt Vonnegut jr.
http://www.youtube.com/watch?v=e5MG1ZfFiZ8&mode=related&search= Mercy now
I think the only thing to do is git.......you have burns to deal with, you have oxygen depletion to deal with, you have structural damage to deal with, then the caustic/ poisoness smoke........
Probably the cure for all that would cost more than the house is worth......
waiting on the revolution..............
Was just observing that a lot of people just barely got away in time, and a few didn't. Especially in an isolated area where your escape route might be cut off, seems like it would make sense.
If your view never changes you're following the wrong leader
escape route might be cut off*****I have no experience in being trapped by a roaring fire, but I can imagine little that would be as frightening or as dangerous......I once said on here that I love storms, but a fire storm? No way.
waiting on the revolution..............
This might answer your question:
http://www.nctimes.com/articles/2007/02/16/news/top_stories/22_29_412_15_07.txt
It's a blog discussing Shelter In Place, or SIP, as proposed by developers in the San Diego area to develop areas with difficult egress in an emergency. The idea is to simply stay in your house. There appear to be a lot of reasons this won't work, but i found the response of the fire safety official from Australia the most convincing:
"I have not heard of such bunkers, and the approach used here specifically warns against hiding. The emphasis is on proactively defending the shelter (the house) from inside as the fire front passes, and then outside as well. Bunkers are likely to become very hot and in at least one case people have died when they sheltered passively in garage under their house. Some people might have sheltered in caves or mineshafts, but that would seem to be quite different from what your man is referring to."
FHB actually did an article on aspects of this a few years back - maybe someone else can identify the issue.
The article dealt with the house a contractor had built for himself that was sealed tile roof, all external surfaces (even under decks) was stucco or metal, fire screening on all vents, reflective coatings on all windows, etc.....
The article showed a pic of the house standing undamaged amid 100's of totally destroyed houses in the neighborhood. Firemen actually used the house as a shelter from the heat.
So, it is possible to even design the whole house to be a shelter.
I was just thinking about that article.also remember something about vegetation around the house.
bobl Volo, non valeo
Baloney detecter WFR
"But when you're a kibbutzer and have no responsibility to decide the facts and apply the law, you can reach any conclusion you want because it doesn't matter." SHG
I remember that one also.
The concept was to keep the interior temperature low enough so the contents would not self combust.
I think this is the house: http://www.taunton.com/finehomebuilding/how-to/articles/fire-resistant-details.aspxWhether what these people did or the houses I linked to or the emergency tents, some conclusions are the same: protect the inside from radiant heat for a finite time period; don't give the flames any place to gain purchase on the shelter; keep fuel away from the fire.I'd rather the house be resistant to the fire, than have a safe room that is, because the rest of the house would just be more fuel and make it all the harder for the safe room to be safe.Edit: This thread should be in construction techniques rather than the Tavern.
Edited 10/24/2007 12:13 pm ET by CloudHidden
That's the one.
I thought that is what you were alluding to with your earlier "monolithic" links. Keeping the interior relatively cool.
I do have a dome question though. Is the foam damaged during a severe fire? If so, then what? Remove and replace?
I'll recast the question as a generic foam to the exterior question question, because it also addresses ICF. The answer is, it depends. Depends on the intensity and duration of the flames. Depends on the coatings. If the foam is protected by concrete, the answer is different than if it's protected by vinyl. Since the foam is never initially exposed, the damage will depend partly on its covering.Damaged foam can be cleaned and refoamed. Not a pleasant task, but it can be and has been done.With any disaster--fire, tornado, flood, hurricane--the first goal is survival. After that, the goals become preservation of important possessions, and then move on to rebuilding. Anytime we can limit damage to cosmetic rather than structural, we've accomplished something. Nothing is disaster-proof, but the more we can limit the damage, the better off we are.In watching the news about the CA fires, I heard that some people had only 10 min to gather what they could. Priorities were family and pets. After that, my thoughts were for pictures and momentos that couldn't be replaced (wedding album, etc). If I can't take all that with me, I'd like to be comforted that it wouldn't all blow away or burn up. I felt that way in the prior house, but feel much more exposed now.
There was a piece on NPR this morning about "Shelter in Place". Apparently some communities have adapted the concept as code, and homes built to the standards did well in the fires.
I can't imagine any such thing being feasible, without first taking steps to keep the fire as far from it as possible. That is, clearing brush, maintaining set-backs, etc. These are things that are already encouraged ..... and not done!
However ... a lot can be done for property protection. An awful lot can be accomplished with an extra layer of drywall, window shutters, and metal roofing. Here's where I get to be a bit of a grump:
Were it not for our easy insurance, overly generous aid, and 'temporary' residence habits .... I suspect a LOT more would have been done by the occupants to protect the homes.
On the bright side, odds are that a fair share of the destroyed properties were inefficient, overly remodeled dinosaurs, which probably should have been demolished and replace decades ago. The arsonists may have performed a public service.
The arsonists may have performed a public service
If you really beleive that, I'll forward my homeowners insurance bill to yu so you can pay part of it as a 'public service'
These fires, like hurricanes, and unlike tornadoes, generally arrive after many hours or days of warning. People who say they only had a few minutes warning are usually talking about the evacuation order, not when they first learned there was a fire. It makes little economic sense to spend money for an adequate fire shelter. It would just encourage more people to stay home, like those who are interviewed before every hurricane: "We're just going to ride it out." As though the storm or fire cares how brave you are.
Leaving early, rather than waiting for the evacuation order makes $$ sense. You could fly to Paris and stay at the Ritz for a lot less than a shelter that might protect you (or not) would cost.
Except that for some in more rural areas the escape route may be in risk of being cut off days before fire could potentially reach the home. And often an area that seems safe turns out to be suddenly at risk due to a wind shift.
If your view never changes you're following the wrong leader
why couldn't somebody come up with a design as a hazard shelter, maybe hurricane, fire, tornado. Like a small concrete out building.people say, you know hurricane coming, get out of town, well my house is at elevation 81, so flooding not going to happen, no trees, no powerline, just wind damage.so I load up my truck, it get 23 mpg and has a ten gallon tank, 200 miles. traffic will be bumper to bumper and then when I run out of gas, the station be closed, then hotel room, I would have to go to Iowa for vanacy, it would cost me a couple thousand to leave for a week.so you start with the emotion response, well look what happen to nawlins, yes it was bad, it is also the only city in United states to be below sea level. It cant happen like that no where but nawlins.Waveland Ms. is right across from nawlins, wave land is twenty feet from the gulf. it got wipe out, flooded, but hour after the storm it was dry land, well soggy land. the eye went over waveland. I think I would think of a new name, waveland got wipe out by a wave.but if everybody had a shelter, why put a million people on the roads..
Dont believe a word I say, I am alway wrong, just ask BOB
Keep in mind that there is absolutely no requirement ... even for fire-rated doors .... that they be able to operate after exposure to fire. Indeed, they are usually so warped that you'll need a jackhammer to open them.