Where should you direct an elevated stream near ventilation?

Directing an elevated stream toward a horizontal plane is the correct approach because it maximizes the effectiveness of the water stream in cooling the fire and preventing its spread. When the stream is aimed horizontally, it allows the water to cover a broader area, effectively penetrating the heat and smoke layer where the fire is most intense.

Aiming directly at a horizontal plane helps to protect firefighters and the structure itself, ensuring safety and reducing the chances of flare-ups. Additionally, this method can create a cooling effect on the surrounding materials, which is vital in controlling the fire's growth.

In contrast, directing the stream straight up toward the roof may cause water to dissipate in the heat and not effectively reach the fire. Aiming it toward a vertical plane could cause water to run off without adequately soaking the fire-affected materials. Directing the stream away from the building doesn't address the immediate fire threat and can allow the fire to spread without intervention.