What is the term for the forcing of air into a building by means of fans?

The correct term for the forcing of air into a building by means of fans is ventilation. Ventilation refers to the process of exchanging indoor air with outdoor air to ensure a fresh supply is available, which can involve mechanical systems that use fans to actively introduce air into a space. This process is essential for maintaining good indoor air quality and ensuring the comfort of occupants by removing stale air, odors, and pollutants.

In contrast, infiltration describes the unintentional entry of outside air into a building, typically through gaps and cracks, without the aid of mechanical systems. Exfiltration is the process of air leaving a building, often through similar unintended openings, again not relying on mechanical means. Recirculation refers to the process of returning air within a building back into the air handling system after it has been filtered and conditioned.

Ventilation specifically emphasizes the controlled introduction of fresh air, highlighting the importance of actively managing indoor environments for health and comfort.