Both the fan and its supports must be designed for working under fire conditions. For road tunnels, these requirements usually imply ensuring fan normal operation at 450ºC during, at least 2 hours. But sometimes additional safety requirements have to be met. This was the case of a fan that was manufactured in 2006 for a mine in Peru. The client required ensuring proper operation at 600ºC during half an hour. To certify this, a physical test had to be carried out before installation in field. The overall design was structurally checked by simulation to ensure that this requirement was going to be fulfilled and therefore that the physical test was going to succeed.

Particularly critic was the fan motor which had to be cooled for correct operation, so a special refrigeration system was designed with the aid of simulation.

The fire test was carried out in an independent lab in Germany in February 2007. Finally, the fan was able to withstand the temperature condition (600ºC) at normal operation during more than one hour, which was an important achievement both for AST and for the technical team of the fan manufacturer.