It depends on the outside temp. If you move enough air the temp inside will just about equal the temp outside. I do not know how mean CFM it will take but my guess would be about 500 to 1000 CFM with good ventilation. Now if you are trying to cool the room with a A/C unit you will need about 1 1/2 tons of cooling. Do to the energy cost I would install a swamp cooler because they are cheaper on the electric bill.