A project includes a zone with operable windows for natural ventilation. The zone is not served by any heating or cooling equipment. According to Section 402.2, is a mechanical ventilation system required for this zone?

• No, but only if the natural ventilation openings are permanently open.
• Yes, but only if the natural ventilation openings can be closed.
• Yes, a mechanical ventilation system is always required when natural ventilation is used.
• No, a mechanical ventilation system is not required because the zone lacks heating or cooling equipment.