Exhaust fans or blowers should be located on the weather deck when possible so the exhaust ducts within the ship are under __ pressure.

• A. Positive
• B. Negative
• C. Neutral
• D. Zero

Answer: (B)

When dealing with exhaust ventilation, the goal is to prevent contaminants like smoke and fumes from spreading to other compartments. Keeping the exhaust ducts under negative pressure relative to the surrounding spaces means air will flow from the spaces into the duct rather than from the duct into the spaces. This containment helps pull contaminated air into the duct and carry it out of the ship, rather than blowing it into adjacent areas. Placing the fans on the weather deck supports this by providing a reliable path to discharge overboard while maintaining the negative pressure in the duct network. So, the exhaust ducts within the ship are kept under negative pressure.