Positive Pressure Ventilation or PPV is the use of a fan, pictured above, to force air into a building.

This increases the pressure inside and drives out heat, gases and other products of combustion.

As most of the work required to set up PPV takes place outside the building, firefighters and equipment are not unnecessarily exposed to hazardous interior atmospheres.

The fan typically provides a flow of cool, fresh air into the building at the point where firefighters make their entry.

It achieves many of the benefits of natural ventilation more quickly, and is more controllable and targetable than natural ventilation and less susceptible to erratic wind conditions.