According to the Ashare standard, for the ventilation of different spaces with different applications, a certain number of air changes per hour is recommended so that the air quality inside the building is acceptable for the occupants. This standard is based on the reduction of pollution in the ambient air. The amount of air required for different spaces is calculated from the relationship Q=V x n, where Q is the air volume (…, cfm, m3/h), V is the volume of the desired space (ft3, m3) and n is the number of times Air exchange in hours for different spaces.