Industrial ventilation question!!!! Please Help?

Question

The air flow exhausted out of a room with dimensions 30’ x 30’ x 10’ is 4500 cfm. Calculate the number of air changes per hour. What do you know about the relative safety of this room with regard to the concentration of a solvent evaporating in this room, based on the ACH value? What happens to the number of ACH if the room volume was half the original amount? What does this changed ACH tell you about the concentration in the smaller room compared to the larger room, at equilibrium conditions?

Answer 1

Your room is 9,000 cubic ft (10' X 30' X 30' = 9,000 cf), so there are 30 changes per hour.

For half the volume, there are 60 changes per hour.

In terms of concentrations, There is 2X the concentration in the smaller room, but 2X the changes as well.

You ability to evaporate solvent is dependent on your air handling more than room size.