I have purchased 3 of these and they are excellent ! I installed 2 in our RV garage and later the other one in our 200 sq ft kitchen. What I have come to understand is, if you get the right amount of them in the area you need it , it will create it's own atmospheric conditions. For instance in our kitchen I can get a nice breeze on a calm day! In the garage, we now have a breezeway into the house through the laundry room! I can't imagin why anybody would go less than 700 cfm..