Which statement is true regarding the necessity of air replacement in buildings?

The statement that air must be replenished whenever it is exhausted from a building is accurate because effective indoor air quality relies on a constant exchange of air. Inhabitants breathe in oxygen, which is then converted to carbon dioxide and other contaminants that can build up in an enclosed space. Without proper ventilation and replacement of the exhausted air, the indoor environment can become unhealthy, leading to issues such as poor air quality, discomfort, and potential health risks.

Replenishing air ensures that fresh, outdoor air enters the building, helping to dilute indoor pollutants and providing necessary oxygen for occupants. This process is critical in environments such as offices, schools, and residential spaces where people spend significant amounts of time. Proper air replacement also helps manage humidity levels and temperature, contributing to overall occupant comfort and well-being.

The necessity to replenish air is fundamental to maintaining a safe and healthy indoor environment, which underscores the correctness of this statement.