What can be a primary path for fire spread?

A ventilation system can serve as a primary path for fire spread because it often extends throughout a building and is designed to circulate air efficiently. When a fire occurs, the heat and smoke can travel through the ducts, carrying flames and toxic gases to different areas of the structure, often bypassing barriers that would typically limit fire spread. This characteristic makes ventilation systems particularly vulnerable points in terms of fire safety, as they can facilitate the rapid transfer of fire and smoke, potentially endangering occupants and complicating evacuation efforts.

In contrast, while air ducts, exit routes, and electric lines can also play roles in the dynamics of fire spread, they typically do not serve the same direct and widespread facilitative function as a well-designed ventilation system. For instance, air ducts may not connect all areas of a building in the same manner that a ventilation system does, and exit routes are primarily designed for evacuation rather than fire spread. Electric lines can carry heat and spark electrical fires but do not inherently provide a pathway for the physical movement of fire like a ventilation system does.