What characterizes mechanical ventilation?

Mechanical ventilation is characterized by the utilization of controlled exhaust systems. This type of ventilation is intentional and designed to manage air exchange within a space systematically. By employing mechanical means such as fans or blowers, mechanical ventilation facilitates the movement of outdoor air into a facility while expelling indoor air, thereby ensuring adequate air quality and controlling temperature and humidity levels.

In mechanical ventilation, air exchange is not left to natural forces but rather is regulated according to specific requirements of a building or system. This precise control makes it particularly effective in various applications, from residential homes to industrial facilities.

The other options do not accurately describe mechanical ventilation. For instance, dependence on natural airflow implies a reliance on surrounding environmental conditions, which contrasts with the active and controlled nature of mechanical ventilation. Similarly, passive openings refer to passive ventilation methods that do not utilize mechanical systems but rely on temperature differences and natural drafts. Lastly, reliance on heating systems is not inherently connected to ventilation itself, since heating systems can operate independently of ventilation and focus solely on thermal comfort without addressing air quality or exchange.