Which statement reflects the three-sided approach's purpose?

• A. Consider wind direction, backdraft risk, and exposure to adjacent structures
• B. Ignore wind direction
• C. Consider only wind direction
• D. Consider exposure to adjacent structures only

Answer: (B)

The three-sided approach for vertical ventilation is about planning with three critical factors in mind: wind direction, backdraft risk, and exposure to adjacent structures. Wind direction helps you predict how air and smoke will move and guides you to place the opening so the exhaust path is safe and effective. Backdraft risk warns you not to vent under conditions that could trap fuel-rich gases and ignite explosively once air is introduced. Exposure considerations protect nearby buildings and contents from fire spread and radiant or direct heat.

If you ignore wind direction, you lose a key control over how the ventilation will alter pressures and airflow, which can drive fire toward the opening or worsen conditions inside. Focusing on only one factor misses the safety balance the three-sided approach is designed to achieve, increasing the likelihood of backdraft, unplanned spread, or unsafe venting outcomes.