In a line of ventilation stoppings separating intake from return, how many temporary stoppings may be immediately adjacent to the last line of cut-throughs?

• A. Exactly 3
• B. No more than 2 immediately adjacent to the last line of cut-throughs in the panel unless a separate panel is to be developed and there is a plan for installing permanent VCDs
• C. No limit
• D. Only 1

Answer: (B)

Ventilation control around the boundary between intake and return air needs careful management. The last line of cut-throughs marks where airflow is being segmented into different sections, so piling up temporary stoppings right next to that line can create a maze of barriers and disrupt predictable air flow. Limiting to no more than two temporary stoppings immediately adjacent to that last line helps keep the boundary controllable and makes room for permanent ventilation controls to be installed later, ensuring safer and more reliable ventilation.

There’s an allowance for a different approach if a separate panel is planned and permanent ventilation control devices will be installed there. In that scenario, the arrangement can be organized with the long-term controls in mind, rather than relying solely on temporary stoppings. The other options would either push beyond the safe, manageable limit, ignore practical control needs, or be unnecessarily restrictive.