Sir let me say to you when you say ever walk in to a server room, well he has no idea what you are talking about. but I do in my area we call them data rooms and I have did the A/C and exhaust in hundreds of them not one not 2 but 100s, as for the concept of the supply air coming from the floor ,yes this is always done in data rooms , A company called Liebert has the leading tech on products to cool data rooms , but not to get to technical about the installation and why the cooling is supplied from under and not a standard overhead system , but lets say the only reason why it is designed this way is because of space issue ,being you have been in these small Locked rooms (security reasons as you know) as you can see the amount of equipment stuffed in them and all the fiber optic that goes with it. ,but there is nothing wrong with your makeup air design from the floor. you may have got this idea from being in data rooms but ,we install it that way because the servers and fiber optics and all the other data equipment have priorty placement.