We have a multi story underground parking structure that is exhausted with 26,000cfm P1, 32,000 cfm for P2 and P3. The exhaust fans run 24/7 and are controlled by a manual switch that is never turned off. Our calculations show that we far exceed the pressure for both categories however for levels P2 and P3 we do not meet the .5cfm per ft2. In order to meet the .5cfm per ft2 the exhaust fans would have to be almost 60,000 cfm, however this would greatly increase the pressure within the space to about 30. Is it possible to submit showing that we far exceed the pressure needed for the space yet not have the required .5cfm/ft2? Has anyone had any luck this way?