*Saferooms, What's working*
14 x 13 x 8 bedroom
14 x 11 x 8 bath
For a total of 2688 CUBIC feet
The air heat vents were sealed with plastic, as was the Bathroom vent fan and doorway. We will normally have this door closed, but wanted it open for this test as a visual aid...
Results were crudely monitored by a "pressure altimiter" and visual cues (IE: the plastic on the doorway bulging or not)
We tried one computer fan with a Hospital HEPA face mask attached to the back.. the CDC literature says it can be used in the collection of the small pox virus.
No results were measurable.. dismal failure.
We added a second fan: No measurable results.. dismal failure.
Our second test was with the Wal-mart air bed inflator with a NATO standard NBC filter attached. After about 2 minutes the plastic began to buldge outwards in the doorway.. after 15 minutes, the altimiter began to show a rise in pressure.. This was effective.
Update: 03 May 2005
Kwll just experimented with these using the newest models.. he said the new models didn't last 10 minutes before smoking the motor. He also had to use a connecting tube to go between the NATO Filter and Air-pump unit.. so If your NATO flter doesn't fit snugly without extra tubing, you have a new model that may not work very long.
Second unit was placed about 1 foot from the first... results were seen in under a minute.. this was more effective. The motors in these little units are NOT designed to run for long periods of time, and expecting them to run a month or more is unrealistic, expecting them to run all day is probably unrealistic.
We reversed the ULPA filtered General Electric Hospital Vent fan in the bathroom... (Our primary method as of this writing.. results were almost instant... so I had to tone it down some)
Now, Trust me on this one, my head is pounding to prove it.. you DO NOT want that plastic sheet to suddenly billow out taunt.. that's WAY TOO MUCH PRESSURE! I was experimenting with fans and got too much pressure on the room too fast and it gave me a reverse sinus blockage and basically shoved snot up into my sinus cavities... because of this I couldn't hear well for a few days and then got a sinus infection.. I'm on sinus medication and antibiotics as I type this.
Let your fan(s) run for about 15 minutes and then the plastic should be SLIGHTLY pushed out.. if it's pushed out TIGHT you have WAY TOO MUCH PRESSURE... Go around the room with smoke per my article (householdairleaks.htm) as long as the smoke is all going OUT you are fine, doesn't matter how many air holes you find as long as that smoke is going OUT of them. There is no need to "Seal a room with plastic", you simply want a little pressure in the room to keep air moving OUT of it.. Viruses and such float with the wind for short distances, but they can not float "Up wind". As long as there is air moving out of the holes, the little buggies are blown away instead of being sucked in.
If possible, go around the outside of the safe room with smoke and make sure none is being sucked in...
Remember, air comes in from the lowest point in your house and chimney's up to the highest point. Those fans on the roof spinning will show that..
You may want to create a hole somewhere else OUTSIDE of your safe room to draw in air (Open a window or something) and THEN try putting the pressure on the room... you don't want to try to fight the natural "Draw" of the house.
Measure your safe room in CUBIC FEET (Length, times width, times height) NOT Square feet... CUBIC FEET, since that's the ACTUAL space you have to fill.
The Best Method we've found so far is "Whole House Units". Our General Electric Air Filter was designed for Hospital pressure rooms and is reversable (No, I don't know where you can get one, so please don't write to ask). It puts out enough pressure to do our whole house. I like the whole house method because staying cramped in one small room for a month or more simply is not feasable.
ABOVE: This is our secondary Hospital isolation room Unit (Also by General Electric). Requires installation and common Hospital Filter stack... CFM not mentioned, but it has 4 speeds "Low / Medium / Medium High / and "OH-MY-GOD". On high this unit will burst your ear drums if used in a sealed house (Yeah, the whole house). On high this unit used about 750 watts. On low it uses about 300 Watts. Filter Stacks are easily obtainable down to Level 4 Bio-containment levels.. it'll still do your whole house even with this much filter stack. Designed to run for years.
NOTE: When Carrie and I fired ours up, it cycled to high and slid the 40lb unit across the floor like a jet engine and blew blankets all over the room prompting Carrie to yell "HO-LY SHEEE-IIIIIT!!!!"... this MUST be mounted securely and have duct work. On a Medium setting it will do a whole large house easily, "high" is WAY overkill. Availability unknown
OK.. this is what WE have tried so far.. we'll add to this as Brian and the rest of the guys get their parts done and tested...
The Best Unit we've tested to date (And this is now 2007, after YEARS of testing, is the "Fan In A Can" (FIAC) that Warlord invented.. It's too complicated to go into here, but the article explains it in detail, and it's been tested by various members MANY times (Most members have these now) through MANY emergencies, even "Shelter in Place" emergencies with Various Chemical Spills.
The FIAC was originally invented to combat relatively large sized things, Like Anthrax Spores, but has been refined and re-made over the years to filter down to the smallest Airborn Capable Particle (Physics says a particle must be 0.4 Microns to be Airborne, and the FIAC is designed to filter MUCH smaller particles as of this writing).
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