Which system is designed to provide fresh air and remove stale air from a space?

Ventilation systems are specifically designed to introduce fresh air into a space while simultaneously removing stale air. This process is crucial for maintaining indoor air quality, ensuring that occupants have access to clean air and reducing the concentration of indoor pollutants.

Ventilation can occur naturally through openings such as windows and vents, or it can be mechanized through HVAC systems that actively circulate air. Unlike heating systems, which primarily focus on raising the temperature of indoor air, or cooling systems, which lower the temperature, ventilation systems address the air quality aspect directly by managing the exchange of air. Filtration systems, while important for cleaning the air, do not provide the fresh air necessary for proper ventilation; their primary function is to remove particulates and contaminants from the air that is already being circulated.

Thus, the core function of ventilation systems positions them uniquely as the solution for the fresh air and stale air exchange, making this the correct choice.