Which statement about two independent means of ventilation in B28 is NOT correct?

• A. They provide redundancy to ensure continuous dilution of leaked refrigerant
• B. They ensure dilution even if one ventilation path fails
• C. They must vent to the same single space
• D. They operate independently to avoid common failure

Answer: (C)

Two independent ventilation paths are provided to ensure reliable dilution of leaked refrigerant even if one path is blocked or fails. Each path operates separately, so a problem in one does not disable the other, keeping the area protected from accumulating flammable concentrations. They should vent to separate spaces or zones so that the protection isn’t compromised by a single issue in one location. If both paths vented into the same space, a failure or adverse condition in that space could affect both paths at once, defeating the redundancy and increasing risk. That’s why the statement that they must vent to the same single space is not correct. The intended design is redundancy and independent operation to maintain continuous dilution across multiple areas.