I'm going to have one 120mm intake fan in the rear, which rates at 80 cfm. And I will have 3 80mm exhaust fans, which, combined will have around 83 cfm. Is it correct to calculate it this way and will the 3 cfm make it too uneven(I wouldnt think it would.) Also, I'm gonna have the 120mm intake in the rear, while there will be 2 exhasts in the front and 1 in the top. Does that configuration sound like it will work efficiently?