What must be provided during periods of occupancy according to the ventilation standards?

Ventilation is essential during periods of occupancy to ensure a healthy and comfortable indoor environment. Proper ventilation allows for the exchange of indoor air with outdoor air, which helps to remove contaminants, excess moisture, and odors, while also supplying fresh air necessary for good indoor air quality. This practice is in alignment with building codes and health standards that emphasize the importance of maintaining air quality for the occupants.

In various settings, insufficient ventilation can lead to issues such as the accumulation of carbon dioxide, volatile organic compounds (VOCs), and other pollutants that can affect the health and well-being of individuals within the space. Therefore, meeting ventilation standards is crucial during periods of occupancy to provide adequate air circulation, ensure comfort, and comply with safety regulations.

While heating, cooling, and air purification are important for creating a comfortable and inviting atmosphere, they do not address the fundamental requirement for fresh air exchange which is specifically covered under the ventilation standards. Ventilation focuses on refreshing the air in occupied spaces, making it the correct response to this question.