Final answer:
To determine the minimum exhaust fan square footage to service a house with a required 6500 CFM, you need to calculate the average air velocity in the duct and use the square footage per CFM conversion factor.
Step-by-step explanation:
The required CFM (Cubic Feet per Minute) of 6500 can be used to determine the minimum exhaust fan square footage needed to service a house.
To do this, we need to know the average air velocity (V) in the duct. Since the volume of the duct needs to be equal to the house's interior volume every 15 minutes, we can calculate V by dividing the required CFM by the product of the area of the duct and the conversion factor, which is 7.08.
Therefore, the minimum exhaust fan square footage needed can be determined by dividing the required CFM by the product of the air velocity V and the square footage per CFM (which is 0.03529).