A manufacturing process uses the powerful solvent acetone. One phase of the process is to dry out the acetone in a drying area. The drying area evaporates $2$ gallons of acetone per hour. Calculate the amount of ventilation $(f\frac{t^3}{h}r)$ needed to maintain vapor concentration below the burnable level. How many times per hour would the ventilations system exhaust a room $9ft$ by $12ft$ with a $10ft$ ceiling?