[sc0pe87]

Hey everyone, I'm a total newbie to preparedness but the way things are going I'm starting to prepare for the worst. I've been thinking a lot about bunker building, particularly the amount of air available, and it struck me that you need an awful lot! e.g. in a 1m radius pipe of 4m length, the total oxygen content would be 2626L, which is a maximum of about 5 days' worth - it would be less than that considering that you need a certain pressure to get it into your lungs. Added to that is the obvious buildup of carbon dioxide. Both of these problems are exacerbated by burning fuel.

I know that the obvious solution is to have ventilation inside the bunker, but If chemical or biological warfare was ever used, I don't suppose most people would be able to afford the kind of kit needed to filter it all out. Also, if the airway should get blocked would you volunteer to go out into the abyss to get it going again?!

I'm experimenting with chemical approaches to these problems, particularly sodium percarbonate. If you're not familiar with it, its the stuff in those oxygen bleaches for laundry, its essentially washing soda with hydrogen peroxide dissolved into it. The hydrogen peroxide is a source of oxygen, but I have no idea whether this is a feasible solution to the problem. I'm thinking of it as an emergency oxygen backup mostly, and you'd need a huge amount of the stuff to get a sizeable amount of oxygen out of it (~5Kg per person per day)

I don't know what you guys will think, so please get back to me to tell me if I'm being an idiot or not!!! I'm going to carry out some small scale experiments with it anyway.

 

[hunker]

Some simple things you can do ....

First of all, be REALLY careful with Oxygen. If you are a smoker, simply put a lit cigarette into pure oxygen and see what it does... Keep away when you do it ... Now, as for providing breathing oxygen ....

A HEPA filter for outside air will stop lots (sorry, not all) of tiny particles that carry radiation from bombs or meltdowns. Have a few spares if you plan a long time of risk ... After filtering the incoming air use an air pump to bubble filtered air in water tanks, producing very tiny bubbles (use a bunch of aquarium bubblers and a big tank of clean water) Bubbles through lots of water will take out water soluble compounds and wet the remaining tiny particles so they can't leave the water. Bubbling through a few stages will further purify the air. Also, bacteria, fungi, etc. will often take up residence in the water as they pass through. A dose of chlorine in the water in later stages will help kill off lots of bacteria and viruses. Activated charcoal air filters will capture some of the smelly escaped chlorine and other compounds AFTER the water filtration is used ... Air that smells a bit like the vicinity of an indoor pool, however, may be reassuring in that bacteria are not as much of a threat. Avoid too much chlorine in the air, though. Bubbling through solvents such as alcohol may remove more organic compounds, though you will need a steady supply of drinkable alcohol to keep the tank working. Don't breathe what you don't want to drink... If you know what's in the air, maybe there is a safe solvent to capture it.

Wet paper air filters can also capture stuff from the air. Sorry - no guarantees just maybe better odds... Sometimes wet air filters release droplets that carry contaminants through ... so your mileage may vary ... Don't force lots of air through any filter in any case ... As long as you get enough filtered air, less and slower is better than more and faster.

These are just simple home-brew measures that are simple and mostly safe. They are no substitute for gas masks, suits, etc. in a true gas or CBW attack. They are also no substitute for fallout shelter-grade filters in the event of a nuclear war or accident. But they will clean a lot of air of a lot of trouble.

As for combustion air, your generator engine should probably draw intake air from outdoors and run the exhaust there too. Also, if there is a PCV system make sure it vents outside... EVERYTHING vents outside.... Combustion for cooking might be able to draw and exhaust outside air if you cook in decently sealed pots and have a fume hood drawing and exhausting from outdoors. You need a fan to pull the fume hood air outdoors with a vacuum when you open the doors ... so it doesn't escape indoors. Of course a crock pot, running on electricity, doesn't need a fume hood... but generator fuel is not trivial.

Overall, when you choose to protect yourself from threats in the outside air (or water, for that matter) you are taking on a monster. Even if you survive, you will find, as the Japanese seem to be finding now, that it is really hard to determine when it is safe enough outside ... or how safe it really is inside OR outside.

Let's hope nobody needs to test air and water filtration measures from warfare or attacks.

 

[Brettboat]

What kind of bunker do you plan on building exactly?... I've built a few for reenacting in many styles...

 

[TMcArthur]

1 meter by 4 meters? That is cramped. You don't plan on standing up for the entire duration of your stay, do you? Could be weeks.

I wouldn't be concerned that someone will decide to hit you personally with chemical weapons. And unless you live NEXT DOOR to a high value target, you haven't got anything to worry about there. Chemical weapons are extremely limited in their usefulness and area of effectiveness.

As for biological weapons, those things don't just waft thru the air for miles looking for someone to infect. They are spread by vectors and require close contact or they don't spread. Unless you think some infected person was going to start blowing down your air intake, air filtration won't matter there either.

In an small underground shelter you want air flow. I have linked to a page which will give the the air flow required per person in cubic feet per minute, based on local climate. 4 people in the hottest, most humid areas could easily require 200 CFM constantly, 24/7.

http://www.survivalring.org/TR87-map.jpg

You will notice that it isn't the heat by itself that causes high ventilation requirements, it is heat coupled with humidity. The humidity in a shelter will rapidly climb to 100% and during the warm part of the year you will quickly die from heat exhaustion if you don't leave. Winter brings its own problems with regards to ventilation. Unless you have a forced air heating system or electric heat you have to worry about carbon monoxide poisoning and excessive carbon dioxide levels.

An electrically powered 12v. ventilation fan is your best bet. Something like this. The batteries should not be in the shelter with you. Use inverted Js and simple filters to filter out fallout particles. Just stretching pantyhose over the opening is as much filtration as you'll need. More will unduly load your fan without accomplishing anything extra.

Likewise, unless you are sitting within a few miles of a high value nuclear target, there is not much point in more blast protection than an ordinary tornado shelter would provide.

 

[sc0pe87]

I did say 1m radius, so 2m x 4m. I'm thinking about concrete or steel pipes buried in a concrete block.

I live quite a way from any major city, but even the US/UK military weapons arent 100% accurate. Foreign weapons would surely be even more inaccurate, so I'd personally not take the risk. Having said that, I simply dont have the money to build anything right now, plus the fact that I dont know where my job will take me.

@Hunker, thanks for the advice on a HEPA filter, I didnt know they were that good.

The one thing I worry about though is that all these ventilation and generator systems would be obvious and make you a target for anybody who's scavenging the area. Bear in mind that in UK we cant buy guns to defend ourselves, I'd want to be next to invisible.

 

[hunker]

A Hepa filter is certainly better than pantyhose over the air intake but, as people are showing with Fukishima, radioactive particles get really small, until finally they are naked atoms and molecules - really tiny stuff won't get caught. Note all the videos showing radioactive rainfall on cars, trash cans, etc. (rainfall in North America) Rain condenses on tiny particles, some of them smaller than Hepa filters will stop.

Then again, if you are expecting even minimal blast effects, the radiation exposure you will be experiencing is very high, the dust and soil will be hazardous, and that is a major problem. If that is the objective of your preps, I would say you should research fallout shelter designs very thoroughly and make your trade-offs.

The advice re: air volumes/heat/humidity is particularly important if your shelter is small, so you have a problem much greater than low volume do it yourself air purification can solve.

 

[arleigh]

Getting mixed thoughts concerning bunkers and raiders and chemical weapons.
Certianly having a place to be safe is important ,but in the event you are discovered ,some one laying sege pumping gas or propane in the intake air while you are unaware of the attack,could be one's undoing .
Comming to the conclusion that a bunker is good for natural desaters and events that potentially will distroy all serface life. In that case there are no preditors going to survive out side .
However those preditors that have survived in places thay have taken will continue to be an ongoing threat.
A strong community capable of being self sustaining ,should in alll prudance have their own anti terriorist teams , teams plural , many of them . Not just for around the perimiter and internally, but roaming teams that seek out raiders, and eliminate them .
If the community has the resources to support these teams ,potential threats would be reduced to a minimum .
You don't look at it as protecting the innocent prepers, out side the zone of your influence, but simply eliminating any raider threat, the scum of mankind remaining.
The problem is telling sharks from sharks, like cops that go bad for any number of reasons , dealing with a criminal element long enough ,trying to underdstand and apprehend them ,one's mind is moved to make compromises in their lifestyle to blend ,becomming a criminal them selves .
Never the less, how else are raiders going to be kept in check ?
If the rulling element remain criminals, it will not return to a free society again .
Un like the time this country was founded and there were a lot of places to hide ,this world is crowded now and every efort is made so that no one can hide .
If a people are simply going to hide , they will have nothing to say about what life will turn into during their absence.

 

[Zoop]

working with oxygen: Do not use normal grease or it will turn the oxygen toxic to breath and unstable/explosive!!