What is primarily affected by ducting air in and out of a building?

Ducting air in and out of a building primarily affects building pressurization. Pressurization refers to the balance of air pressure inside the building compared to the outside environment. When fresh air is introduced or exhausted through a duct system, it creates differences in air pressure that can influence how air moves within the building. Proper pressurization is crucial for maintaining comfort and ensuring that airflow is directed appropriately, preventing issues such as infiltration of outside air or moisture.

While other options are related to the movement of air, they are secondary effects of pressurization. For instance, changes in building temperature and humidity levels occur as a result of air exchange, but they are not the primary factors directly influenced by the actual ducting process. Similarly, air quality can be affected by the introduction of fresh air, but it relies on multiple factors beyond just pressurization, such as the filtration and treatment of air being circulated. Thus, understanding and managing building pressurization is key when determining the impact of ducting air in and out of a building.