What is a Survival Room?
Air Filtration

The air filtration system that AST™ supplies with the “In-house Family Survival Room” is proven technology that has been used by hospitals, clean rooms and the military for a number of years.

AST™ took these known technologies and combined them into one filter housing, making the unit capable of filtering out airborne particulates from  a dirty bomb (gamma radiation), bio-chemicals (anthrax and small pox) as well as war gases (nerve gas and mustard gas).

The air filtration unit is completely encased with radiation shielding (some air filtration devices on the market have not been shielded!) and comes installed in a decorative chest that looks like any other piece of furniture in the room.

To convert an existing bedroom, AST™ would install a "through the wall" air vent (for air supply) and install a filtration system that draws in outside air that passes through a bank of filters certified for the collection of dirty bomb airborne particles, biological spores (anthrax, smallpox) as well as chemical (NBC or CBRN) toxins (mustard/nerve gas etc.) or natural contaminates and allergens.

The safe, clean, breathable air is blown into your protected living area, with just enough force to produce a slight overpressure in the room. This overpressure keeps any unfiltered air from migrating into the room. This is the same technology used by the US Military to keep solders alive in a CBRN (chemical, biological, radiological, and nuclear) environment.

The filter used in the AST™ unit is a HEPA (High Efficiently Particulate Air filter) and is designed to filter out airborne particulates (solids) down to 0.3 microns in size (Anthrax and Smallpox are approximately 5.0 microns in size).

The HEPA medium texture is very much like blotting paper, made of very thin glass fibers compressed into a sheet.  Air passing through the filter must continuously change directions to pass around the thin, glass fibers.

Airborne particles, like anthrax and smallpox, can’t pass through the 0.3 micron openings between the glass fibers due to their size of 5.0 microns and are filtered out of the clean air passing through.

Particles from a dirty bomb that contain radiation are filtered out exactly the same way.

A filter must collect 99.97% of the particles that measure 0.3 microns, in a test established by the Institute of Environmental Sciences in order to receive the HEPA filter designation.

AST™ filters use four separate filtering medias:


• A pre-filter to catch all very large pieces
• A second pre-filter to catch what was small enough to pass through the first-filter
• A HEPA filter
• A Carbon filter

AST™’s air intake/filtration system is equipped with a spare fan motor as well as a backup battery power source in the event of a power outage. There is also a manually  operated air pump should everything else fail.

AST™ also includes several other items to ensure that the air being filtered into the room is at safe levels for a confined space.

An oxygen (O2) analyzer reads the percentage of oxygen in the air. Clean fresh outside air contains 21% oxygen and can go as low as 18% with no ill effects to humans.

A carbon dioxide (CO2) monitor reads the parts per million (PPM) in the air. Clean fresh outside air usually has 350 ppm and a confined room with 4 adults will read higher. As long as the air filtration unit is operating there is no danger to anyone. The meter reads continuously and anything less than 2000 ppm is fine.