Abstract: A nozzle has a body with a central cavity from which a plurality of fire extinguishant fluid outlets extend. The outlets extend non-radially with respect to the central axis of the cavity, i.e. at least a portion of each outlet is inclined with respect to any plane parallel to and passing through the central axis of the cavity which intersects the portion of the outlet. The extinguishant from the non-radial outlets is thrown towards the walls of the chamber, along the paths. The jets of the fluid induce a rotational movement within the ambient fluid (for example, air) already present in the chamber, thus creating a vortex or rotational movement of the fluid within the chamber. In another embodiment, the vortex or rotational movement is generated by a nozzle assembly of generally cruciform configuration with three or more discharge tubes having outlets formed therein for discharging extinguishant in equi-angularly-spaced directions.