This is usually defined as the act of replacing stale or noxious air with fresh air.
In the eco field it is also important to differentiate between what are termed passive ventilation and active ventilation. Passive ventilation is where no additional electrical or mechanical energy is required to make the ventilation work. Active ventilation on the other hand won't work without using additional energy.
Passive ventilation is an aspect of passive building design and often utilizes heat chimneys and natural air flows across the land to achieve adequate ventilation.
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