About Andair USA


Sharon and Paul also own the company, ANDAIR USA, and are the United States distributors of the Swiss made Luwa of Andair AG located in Andelfingen Switzerland. This company provides ventilation systems, blast valves, air filtration systems, and chemical biological protection for home, corporate, military and government facilities.

Ventilation systems are available for shelters of all sizes for occupancy from 7 to 2,000 persons. Of course, multiple units can be installed in a single shelter facility to meet any capacity requirement (some hardened shelters in Switzerland can handle more than twenty thousand people). All Andair AG air handling units are capable of both electric and manual operation and are hardened against the effects of nuclear EMP. Test samples are subjected to 16 g’s in all six directions to assure ruggedness; paint, metals and rubber hoses are tested against all war gasses; and the HEPA and charcoal filters are tested with a highly technical process to assure the proper volumes and densities needed to filter and absorb all known war gasses.

Utah Shelter Systems

Our most popular model, the VA-150, comes standard with a 1 bar (15 psi) explosion protection valve/pre-filter assembly, air pump, exhaust over-pressure explosion protection valve, hoses, clamps, and GF150 Gas Filter. In peacetime, the system bypasses the gas filter and delivers 177 cubic feet per minute (cfm). With the gas filter connected, the recommended air rate is 88 cfm to allow for complete scrubbing of the outside air.

Manual Operation: We know from hard experience that shelter power supplies can fail. Several times in the last twenty years, we have entered our shelters to fine that the batteries were dead. Sometimes it was because the batteries had reached the end of their service life and needed replacement. Once, a battery charger of ancient design was left connected to the battery bank and it discharged the entire bank when grid power was switched off. On several occasions, lights were left on and the charger was unplugged. For whatever reason, a shelter where the ventilation system is totally dependant on electricity, leaves its owners vulnerable. The Swiss would never allow one of their shelters to be so equipped…all life-critical systems essential for shelter operations are required to be manually operable to assure readiness.

Carbon Dioxide Scrubbers are added to underground shelter systems when there is a threat from smoke or other compromises to the air supply. A hardened NBC shelter should have the capability to shut down the outside source of air for a period of 6 hours, for sealed shelter operation. During the first hours of a nuclear attack, smoke, carbon monoxide, and radiation particles could overcome the ventilation and filtration systems. It is assumed, after this 6-hour period, that carbon monoxide levels from the smoke outside would have dissipated. However, carbon dioxide (CO2), which is an internal threat, builds very quickly in occupied sealed areas. A concentration of CO2 over 3% in the sheltered area is unacceptable.

Each person will produce about .67 cubic feet/hr of CO2. Plan your shelter space to accommodate each person with enough room to breathe safely and comfortably for that 6-hour period. Each person needs 88 cubic feet of free air volume to shut down for 6 hours. Design your shelter with double that volume, to accommodate for furniture, food, water and other supplies. A 10 ft. x 32 ft. shelter will accommodate 14 people and supplies in a ‘shut down’ mode for 6 hours.

It would appear from this example that the shelter could be rather small. However, it should be noted that the air space for breathing must be totally empty space. You must, therefore, add about 5 cubic feet for the mass of each person. You must also add additional space for food, water, supplies and furniture. A good rule of thumb would be to multiple the required air space by a factor of 2.5; and for the example above, the volume of the shelter should increase to 2100 cubic feet. Our 10 x 32 ft. shelter (7 feet of head space, 3 feet of storage below the floor, and 32 running feet) would meet the criteria nicely.

If you plan to accommodate more people than your shut down mode can accommodate, you should purchase our carbon dioxide scrubber, or purchase compressed air tanks. Do not store oxygen tanks inside your shelter. They pose too much of a danger.

During a blast, hot gasses under extreme pressures can enter through the air vents. In order to attenuate this shock wave, a blast valve (also known as an explosion protection valve) must be placed into all air pipes, vents and other penetrations to the shelter. Blast valves instantly shut off the flow of air when a shock wave enters the air vent. This not only protects the other components of the ventilation system from damage, but prevents injury to shelter occupants.

Some shelter manufacturers do not wish to go to the trouble and expense of installing underground shelter blast valves into their air vents, addressing the problem instead by using a very undersized (less than 2-inches in diameter) air pipe. Small diameter air pipes cause a ‘choking’ effect and they hope that only a limited amount of blast will enter the shelter through this undersized pipe…but this also means that only a limited amount of fresh air will enter the shelter as well. This small, open-ended air pipe also allows for continual loss of air pressure and for exchange of air from the outside environment. It is mandatory that continual positive pressure be assumed for the proper protection from war gases.

All Utah Shelter System’s ventilation pipes are constructed from 6-inch diameter schedule 40 steel pipe, which will not burn, crack, or easily distort. This pipe size assures a generous flow of air. All shelters supplied by Utah Shelter Systems are fitted with blast valves that have been tested and certified by ANDAIR’s legitimate government laboratory, thereby assuring our customer adequate protection from these serious life threatening effects.

Rock Cribs: In areas of high blast potential, in order to prevent damage from flying debris and blast, air intake and exhaust vents are sometimes placed into below grade rock-filled pits called, ‘rock cribs’. The four to eight inch diameter rocks inside the crib diffuse the shock wave and enable the blast valves inside the shelter to withstand significantly more overpressure.

Air Volume: How often and for how long the air handling unit should be operated depends on the size of the shelter, the number of occupants, and the capacity of the unit. Assuming a family of six in a 3700 cubic foot shelter, they may wish to operate the air system for an hour every six hours or so to freshen the shelter atmosphere. This schedule is not very close to the level of desperation, but it does maintain good morale and comfort for shelter occupants. In order to maintain acceptable air quality in a shelter housing twenty to thirty occupants, the ventilator should be run for twenty minutes and then rested for twenty minutes. Fifty occupants is considered the absolute limit with a single VA-150 and would require continuous operation to support life. This assumes a steel or concrete shelter with un-insulated walls that will absorb body heat and keep temperatures under control. The combination of insulated walls, lots of occupants, and inadequate ventilation will cause temperatures to soar to intolerable levels in a short period of time. With this many people in a shelter, there will be a larger number of volunteers to operate the system (imagine the consequences of losing power with an electricity-dependant air handling unit under these conditions). The “ventilation officer” will also have the job of listening to the radio (perhaps on headphones) to stay informed about an ongoing situation. For this reason, we suggest that you position the radios near the ventilation unit.

Andair AG Gas Filters protect against the following war gases:

  • Nerve gases - Organic phosphoric acid compound to include Tabune, Sarin, Somane, Tammelin Esters (VX).
  • Blister agents(Vesicants) - Organic arsenic compounds e.g. Dichloro-(2-chlorovinyl) arsine, Ethylarsine dichloride, Methylarsine dichloride. Organic sulfur and nitrogen compounds (mustard gases): e.g. Phosgene oxime, Trichloromethylchloroform oxime, Trichloroacetophenone.
  • Choking agents - Phosgene, Di-phosgene, Tri-phosgene, Chloropicrin.
  • Tear and harassing gases - Halogenated organic compounds e.g. Bromoacetone, Chloroacetophenone, Bromobenzoic cyanide.
  • Blood gases - Arsine (Hydrogen arsenide, Hydrogen cyanide, Cyanogen chloride, Potassium fluoro acetate etc.
  • Incapacitants - LSD, BZ, Indole amino alcanes, Phenyl amino alcanes, etc.
  • Toxins (Bio-toxins) - Bateriological Toxins, e.g. anthrax, plague, tularemia, as well as viral agents such as smallpox, Marburg, VEE. Ebola, etc., Zoological Toxins, Botanical Toxins.
Utah Shelter Systems
Utah Shelter Systems

Gas filters do NOT protect against carbon monoxide and dioxide. A separate filter is available for scrubbing carbon dioxide from the shelter atmosphere during a period of time when outside air is not suitable. This could occur if burning debris is too close to the air intake vent.

The ANDAIR PT and PD series underground shelter armored blast doors are designed for a ‘walk in’ vertical configuration.

The PT series 8” thick concrete fill provides both radiation and blast protection for concrete blast shelters. These blast resistant doors are manufactured in Switzerland have been tested and built to Swiss army standards. They are steel framed, ready to be filled with concrete. The PT doors must always open towards the blast threat. They fit against the wall and frame (not inside), which gives them greater blast resistance and protects them from jamming inside the frame during blast or earthquake movement. The door and doorframe should be poured into the concrete wall of the blast shelter during shelter construction. They can, however, with additional reinforcement, be retrofitted into existing shelters.

Utah Shelter Systems

Our NATO type doors come with a heavy steel skin covering both the back and front of the frame, for additional blast and armor piercing protection.

All ANDAIR PT and PD series doors arrive via airfreight from Switzerland. Delivery time from Switzerland is approximately 3 weeks. Allow time for items to clear customs before taking delivery. We will inform you when your order is ready. Price includes all transport, customs and handling to your nearest international airport. Delivery to your job site can be quoted upon request.

PT1- 3'900 chf80 cm x 185 cm x 20 cm (31” x 72” x 8”)
PT2 - 4'600 chf100 cm x 185 cm x 20 cm (39" x 72" x 8")
PD - 3'230 chf60 cm x 80 cm x 20 cm (24” x 31 ” x 8”)

Other sizes available upon request.

Please call for current pricing on the PT and PD series ANDAIR doors. The dollar rate continues to change (Swiss Francs rising).

*There is a "knockoff" design of the Swiss made PT doors, by a company in the United States with a similar name to ours. Their doors are far inferior (though priced near the same) to the Swiss made ANDAIR and LUNOR doors. Their doors have not been blast tested, and their hinges are far too small and weak to properly bear the weight of the concrete fill. Buyer beware.