Friday, March 28, 2008

Humidity, Fungus & 12 Volt Negative Ion/Ozone Generators

The big problem with all underground shelter is humidity. Not only when occupied, but especially when unoccupied.

My goal before this summer is to have an automated system that runs the air conditioning unit/dehumidifier at a threshold set to keep the shelter cool and dry inside at all times. It needs intelligence to know when the shelter is occupied - through passive infrared detectors (I have 12 now I bought at $1.50 apiece that put out a 3 volt signal when a heat source is anywhere in their detector range out to six meters) and when it is unoccupied.

I had an idea that it would be great to constantly flush the entire shelter with ozone when it was unoccupied and then turn on the fans and import clean air when occupants arrive. This would suppress the growth of all mold and mildew in combination with the dehumidifier. There might even be a timed release of vaporized tea tree oil or another fungal antigen, say every thirty minutes a small spray in all areas, maybe staggered at intervals.

Of course, the other advantage of passive IR is that the shelter can turn on the lights and then the fans, greet the shelterees with a prerecorded WAV file and immediately give status reports on every major shelter system ... food, water, temperature, air quality. This for me is the real result I am working towards, to make the shelter self-diagnosing in all regards. For example, using a magnetic reed switch to know if the positive pressure valve in the storage drum is open and that someone should close it if the shelter is put into pre-attack check mode.

I bought an absolute truckload of bracket mounted reed switches of all kinds but I have not mounted them yet because I want to improve the air quality so they don't rust internally.

Herein has been my dilemma - first continuous power from solar and wind available 24/7 charged automatically, then automated AC, then intelligent climate control. I still have not made it past step one. I am reluctant to mount any more electronic components until I solve the humidity problem. My Rabbit 2000 monitor has accumulated chunks of crusty white fungus inside the casing that look like alien spores, although it has not affected the board's functionality as of yet. I cannot install any more computer hardware until I purify the air down there and all surfaces.


Anonymous said...

You might try a non-electric dehumidifying solution - altho might be hard to find in sunny Australia :

Where is the water coming from ? If it's from the walls/joints of the shelter, that's got to be sealed somehow - if it's from the moisture in the air itself, that's a different kettle of fish. If its coming from the air, I would think about having a series of pipes buried in a deep trench so that they remain as cold or colder than the shelter - not sure how long they would have to be - 30 to 100 meters ? Then just pump the air thru the pipes and the cold in the pipes will draw the moisture out by the time it reaches the shelter. You could pump the air from the shelter thru this pipe system continuously so that any air that comes in with persons entering the shelter gets dehumidified too.

Simple is better. This system, if set up right, might even be powere by someone riding a bike to move the fan blades.

You're right though, that is a major problem to solve.

Anonymous said...

I'll add - entropy is a bitch - you need to make as many of your systems as passive as possible. The electronics you're are working on are cute, they're fun, but they should not be relied upon IMO. Machines fail, systems fail, and you-know-what happens. It would be one thing if you were talking just a few months - but years is again, a whole nother kettle of fish. Like I always tell my better half, if you have to rely on something, then you better have backups of backups of backups and even that isn't enough for an isolated 10 or 20 years. And I'd say solving your technical issues are going to be much easier than the psychological ones you would face in the scenario you are planning for.


Anonymous said...

The thing I love about this blog is the no-BullBiskit contrast between:

(1) the Stupidity of Koko and those buffoonish Negros, and

(2) the Intelligence Design of the Mold Abscess.

I'm convinced. Really.

Texas Arcane said...


Herein is my greatest contribution to the reality of long term shelter design so far ... if we are talking about long term inhabitation (say more than a week) you would not believe the problems that arise due to humidity.

Humans give off moisture. Lots in fact. You would not believe how much comes out of their lungs and their pores. It's not distilled water we're talking about either - it's a germ laden fungus ridden bouillon base of staph-a-matic slime waiting to happen.

Show me the most pristine Star Trek looking high tech clean hygienic shelter you have ever seen. Now just try putting four people in there for one week with inadequate ventilation. That shelter will be one gigantic mold petri dish in seven days.

I believe this is a very important discovery I have made. When other people online are talking about their shelters and how they are stocked for a stay of a month/year/decade, I always know they have not actually run a trial of imhabitation yet or else they would know about the fungus plantation that results.

Without power ventilation and (I realize now) air disinfection and conditioning, it's not realistic to think you can stay in that shelter much more than a week.

The thing is, all this information is in the old navy studies and Oak Ridge Labs research but it takes reading between the lines.

Now when I read about the shelter experiment where the navy subjects had to emerge after a week and a half "because of the humidity," I understand what is being talked about.

Your low tech idea is a very good one. I have been thinking along similar lines as a "backup" air control for a long time. I have in fact thought specifically about putting a sealed ring filled with water or some other heat transfer liquid through a hole into the ground and then pumping it in a circle via one of those small manual/drill pumps you see sold all the time at hardware stores. It's just that it is not a big a priority as getting the powered system running for me. If I get the air system working good with the complex setup, I will definitely begin to investigate the low tech options.

Anonymous said...

P.S. Ten tons of calcium chloride will last about a month in a shelter for passive dehumidification. It's only useful for when the shelter is not occupied.

Anonymous said...

Would it not be better to have an intake that is colder and enters lower in the shelter and have a metal exhaust that exits higher in the shelter and runs up and through a 'solar heat mass' such as a concrete pad; to draw air up and out? A small blower on the exhaust would assist this movement.
There are considerations such as no available sunlight, but it is low tech and may be a passive solution.

I am assuming that when the generator is being used that 240v fans are being used to move air in and through the shelter? In peacetime it would be good to be able to leave main hatch open - with maybe just a zippered flyscreen to let air move.

Just some random thoughts....good to see some creative discussion.

Anonymous said...

Get a high pressure air compresser, run it outside and run cool dry compressed air into the bunker, vacant or full this will dry and keep dry any bunker.
ps you might need an extra source of heat to keep the bunker warm!

Anonymous said...

Yeah, I just got a new milling machine and have been mucking around with the air system - these pretty much require a refrigerated air dryer - this drops the temp of the compressed air down to about 35 degrees F and all the moisture comes out. I would think this would work without a compressor - any air source - and there's a lot of them out there and not that expensive.

I would think that increasing the volume of the shelter would help as well.

There is this technology too :

Also remember that movie Mosquito Coast where harrison ford builds a refrigerator that is powered from burning wood. That might be another way to get refrigerated dry air.

So Tex, so what exactly are you planning to do now to dry the air ?

And I think you're right about your contribution - that wouldn't have occurred to me until I saw all the issues you are having. Nice to have someone actually doing this stuff to learn from.


Neo Supertramp said...

Didn't they have a similar problem on the International Space Station recently? The Russkies blamed the yanks. Could be a nasty tip to Mars if they don't get a solution.

Anonymous said...

Ever considered seperate room made specific for the growth of edible fungi?


Texas Arcane said...

About the heat differential (low entry, high exit for air) all I can say is I don't know who in the hell is writing these books but they need to actually try out these ideas before they nonchalantly drop them into books as recommendations to others.

Basically, I proceeded with the notion from the beginning that this would work. I put the entry for my air a meter lower than the exhaust. I figured in combination with the 12 volt fan that drives the air filtration, I'd have plenty of fresh air. After all, plenty of books said this was the way to do it.

Alas, all of this is crap. I found out the hard way, by following this advice. Humidity control is not an afterthought. It's job #1.

I know now that with a few exceptions, like Cresson Kearny, 95% of the advice you get about shelter design is from shithouse lawyers who have never tried any of the stuff they tell others is the way to do it.

Only two books out of hundreds I have read have really mentioned this problem with humidity for shelter stays over a week. I believe this means that other than those two books, the other couple of hundred were just repeating stuff they had read in another book. If they had tried this for real then HUMIDITY CONTROL would have been Chapter Two in every single freakin' book.

Philip Hoag (No Such Thing As Doomsday) and Cresson Kearny (NUCLEAR WAR SURVIVAL) both mentioned the humidity problem as being very real, very serious and very critical to solve. Kearny designed a unique manual ventilation system with the airflow of an industrial fan to solve a problem few other authors even were aware of. Hoag went the more traditional route, going into great detail of how to run and exhaust an underground diesel generator to power the needed AC unit. That tells me that like with everything else, 2% know what they are talking about and the other 98% are full of crap.

It's like how people are always recommending burial of shipping containers as instant shelters. It's a sure way to kill complete strangers dumb enough to listen. Without reinforcement, those containers will buckle and cave in as soon as you put more than a single foot of earth on top of them. Some poor idiots like me have even found this out the hard way after the expense of trying it for real. It cost me $2800 because I tried to bury a half container this way, the same way I heard dozens of people advise on the Internet. It caved in immediately, of course. It's a really, really stupid idea.

When I get around to building the Grand Redoubt, which is supposed to be the last word in livability in every regard, I am making sure my air shaft there will be a meter wide stainless steel pipe and have an air flow through it powered either by bike or fan to bring a hundred cubic feet a minute of air into the shelter. I also know a much better way to throttle the incoming air without resorting to a blast valve but still provide protection against blast overpressure. Like with the humidity, I guess I had to make a couple of mistakes to know how to do it perfectly the next time.

Anonymous said...

Ideas & Info :

I actually think there are two approaches to this - you can go the electricity/AC route OR another way is to pump large amounts of filtered outside air. Both of course have advantages and disadvantages.

I think it all depends on what you view as your primary goals/weaknesses.

For me I think having to completely rely on an external electrical system - especially one that you will be unable to physically maintain in a prolonged fallout situation is a non-starter.

Peltier type devices are interesting but the efficiency levels even with the recent improvements still leave them far behind conventional refrigeration systems.

It is seems to me that it is much easier to pump/filter large amounts of air than it is to use electricity to heat/cool that air to remove the moisture.

I also think that you have to face the fact that as an individual you CANNOT solve all the problems - prepare for all the possible eventualities - you have to pick and choose your demons. I say this because I don't think blast radius preparations should be a primary consideration. I know this is probably heresy in the world of shelter design but IMO if you built a shelter in an area likely to get directly nuked you're a moron to begin with.

Step 1 in shelter planning - determing where bombs most likely to fall

Step 2 : Move, dumbass.

Building a shelter is primarily for fallout and concealment purposes IMO.

If I take a direct hit from a nuke ... well, you can't win them all. At least the end will be fast.

I say all this because if you need blast protection then the electric/AC route is the way to go - although I guess you could also slap blast doors on your vent holes if need be.

electric fan motors are also long lasting efficient and trouble free. Easier to fix too. You could even do something simple like a series of windmills which drive a fan system directly - no electricity needed.

Whatever you do it has to be as simple as possible if it is going to be used for years. And no matter what - you need to design for years, because your shelter might sit there unused for 10 years before you finally need it.

I think I would go with a triple or quadruple system - air hydro human-powered direct drive fans for the ventilation system. And a electric system with simple air hydro solar and waste motor oil with a lister type diesel/waste oil generator/engine combo.

I would start with the simplest system and build up to the most complex.

Anyways - could go on for pages blah blah blah.


Anonymous said...

BTW that's why I have gotten into learning milling because I have a boatload of projects I will need to complete for a Vault and being able to make virtually any metal/wood part I need from a block of raw material, I figure is going to be an important-to-have skill.

Unfortunately, I don't have the resources to do a Vault right now - but hope to get started in another year or two - assuming I'm not too late :(

So I can't build a Vault now, but I can learn as many of the skills I am going to need anyways to do so.

I don't doubt my family will need one, it's just that my info tells me we're looking at the 2015-2025 timeframe before it all goes up in smoke for real. Read the Fourth Turning (4T) book for a good idea of what comes down the pipe and the timing of it all.

BTW 4T (like Titor) says that if we get another whackjob president like Bush, then Crisis comes early and the earlier it comes the worse it will be.

I have a strong premonition that the winter of 2017-18 is when it all happens for real.

But hey, what the hell do I know.


Anonymous said...

Portable air conditioner with de-humidifier, 1280w power use for cooling and run from 240V (generator). They have a water collection tray that is emptied in 'very humid' conditions and have ducted exhaust. Cost under AU$400.
Run for a couple of hours a day.
Any thoughts??

Texas Arcane said...

My current setup is a portable AC unit. There are three things missing:

1. Independent management and storage of inverter power around the clock to power the AC when needed. At present I've got a diesel genset and most of the makings of a solar/wind station but it has yet to all be set up.

2. I need the monitoring system to turn on the AC when it is required when nobody is home. To do this, it may have to check the battery power and if it is insufficient, turn on the generator before the AC.

3. I need optoisolated control switches for both the generator and the AC connected by fiber optic to the Vault Manager for +5V control signals.

It's not as bad as it sounds. I actually have most of the hardware I need, as soon as I get around to setting it all up.

Texas Arcane said...

The blast valve problem is much easier to solve than people realize. You can have a custom blast valve over your air intake, or you can have dozens of little pipes which will deliver the same volume of air but which are self-throttling by their very nature in that incoming air once it reaches a certain pressure is too dense to force itself in beyond a certain rate. So the overpressure of blast effectively "closes" your air intake by virtue of it being too dense to enter.

There are a lot of ways to implement this. It could be two dozen little 12mm PVC pipes sticking through, with a tiny valve on each if necessary. If the other side has sufficient volume for the incoming air to expand into, all these little pipes deliver the same amount of air only naturally "throttled."

Robert A. Heinlein implemented this system at his own shelter by drilling about 300 holes underneath a guardrail aboveground which was connected at the end to his 150mm air intake. He was near some target centers in Colorado and he knew that it was the ultimate low-tech way to blast proof your air intake. No modifications needed.