What is the calculated ventilation rate for a building with a volume of 2000 m³ and an air change-over rate of 6 per hour?

To determine the calculated ventilation rate for a building, you can use the formula:

[ \text{Ventilation Rate} = \text{Volume of the Building} \times \text{Air Change Rate} ]

In this scenario, the volume of the building is given as 2000 m³, and the air change rate is 6 air changes per hour.

Substituting these values into the formula gives:

[ \text{Ventilation Rate} = 2000 , \text{m}³ \times 6 , \text{hr}^{-1} = 12,000 , \text{m}³/\text{hr} ]

This calculation shows that for the building to achieve an air change rate of 6 times per hour, the ventilation system must move 12,000 m³ of air every hour. This matches the correct choice and reflects the requirement for maintaining indoor air quality and managing potential toxicological hazards effectively.

The other options suggest different ventilation rates which do not align with the calculated requirement based on the given parameters. Each of those incorrect figures results from either miscalculating the multiplication or misunderstanding the relationship between volume and air changes.