To deserve the name of CBRN fallout shelter, the Swiss Federal Office of Civil Protection (known as the reference) requires special closing devices* for all openings in the shelter envelope as well as a ventilation/filtration system for NRBC contaminants (chemical, biological, nuclear, radioactive and nuclear).
* Gastight blast doors, blast valves, overpressure valves…
The ventilation systems that equip our anti-atomic shelters offer protection against nuclear, biological and chemical pollutants. These fans and their gas filter are manufactured in Zurich, Switzerland. They have been approved and certified by the Federal Office of Civil Protection after having been tested by the Spiez laboratory which is the Swiss ABC Protection Institute.
How does ventilation work inside fallout shelters?
The CBRN ventilation/filtration system provides breathable and clean air to the occupants and ensures an overpressure of 50-250Pa in the same time. It consists of a fan (VA) that draws outside air towards pre-filter and a blast valve (ESV-VF). If air contamination occurs in case of major disaster, the filter will remove all toxical agents before pulsing it in the safe area. The amount of air required is regulated by the integrated air flow meter. Finally, even in case of electrical blackout, the device can be rescued manually using a crank.