For natural ventilation of an occupied space, the openable area must be a minimum of what percentage of the floor area being ventilated?

For natural ventilation of an occupied space, the requirement for the openable area is set at a minimum of 4% of the floor area being ventilated. This standard derives from building codes and guidelines aimed at ensuring adequate airflow to maintain indoor air quality and comfort.

Natural ventilation relies on the flow of air through open windows, doors, or other openings to circulate fresh air into the space. The 4% figure is determined to provide sufficient ventilation for the number of occupants and any potential contaminant sources within the space, ensuring that there is enough air exchange to mitigate the effects of pollutants, humidity, and temperature.

If the openable area is too small, it can lead to inadequate ventilation, which can result in poor indoor air quality, increased moisture levels, and discomfort for occupants. Therefore, the requirement is established to help maintain a healthy and comfortable environment.