A project includes a zone that is not served by any heating or cooling equipment. The design proposes to use only natural ventilation with operable openings that can be closed by occupants. 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 are not permanently open.
• Yes, a mechanical ventilation system is always required when natural ventilation is used.
• No, a mechanical ventilation system is not required because the zone has no heating or cooling equipment.