Ok guys, I have a question. When setting up an air conditioning system, which is the best way to set up the Air vents and the retur air grill? Is it better to place the air ducts on the floor and the return airs on the ceiling? viceversa? some other way? It'd be cool to get an answer with some kind of reasoning. Also, this would be regarding the use of high-speed velocity ducts (small diameter air ducts where air travels at high speed). And, if it has any effect on it, I would also add that it is to be used for a modular housing project in Boston. Let me hear some opinions!