What does mechanical ventilation refer to in building planning?

Mechanical ventilation in building planning refers to the systems specifically designed to control the airflow within a structure through the use of fans and ductwork. This includes the intake of fresh air from the outside and the exhaust of stale air from inside, ensuring adequate air quality and temperature regulation throughout different areas of the building.

The choice emphasizing intake and exhaust openings reflects the essential function of mechanical ventilation—actively managing indoor air quality by promoting the circulation and renewal of air. These systems operate independently of natural ventilation, which relies on the passive movement of air through windows and openings, making them critical in environments where natural airflow is insufficient or where pollutants may be present.

In contrast, the other options do not encompass the full scope of mechanical ventilation. For instance, heating and cooling systems provide temperature control but do not necessarily focus on air quality management. Likewise, natural airflow through windows cannot be classified as mechanical ventilation since it depends on environmental conditions rather than mechanical means. The mention of only electrical ventilation systems limits the definition and ignores the various types of mechanical systems that may not rely exclusively on electrical power, such as those powered by other forms of energy.