True or False: The air flow into a building must equal the air flow out.

The statement that the airflow into a building must equal the airflow out is true. This principle is based on the concept of air balance, which is crucial for maintaining indoor air quality and ensuring the comfort of the building's occupants. When the amount of air entering a building is equal to the amount of air exiting, it helps prevent problems related to pressure differentials, such as unwanted drafts, energy loss, and moisture buildup.

In a well-designed building, achieving a balanced airflow is an essential aspect of effective ventilation strategies. It enables the efficient operation of heating, ventilation, and air conditioning (HVAC) systems while also complying with building codes and standards that often mandate specific air exchange rates for health and safety.

While seasonal factors can influence how airflow is managed, the fundamental requirement for airflow into a building to equal airflow out remains constant regardless of the time of year. Thus, the correct answer underscores the importance of this balance in the overall performance of building systems.