Baby seat in the car!!

Okay so I am just curious and thinking lol.. I have a 4 door car.. My son sits on a window side.. We have air vents right in the middle.. So I was thinking if I put the babies car seat in the middle the air will hit the seat right.. And no air will go to my older son... So should I put the baby on the other side window.. But that would mean I can't sit in the back with my baby help me please...