Cooling systems for devices arranged in rows are disclosed. An example cooling system for a datacenter in a building includes a supply air duct to extend lengthwise along a first aisle within the building. The first aisle is defined between a first row of computers and a second row of computers. The first row of computers provides passage of a first current of air from the first aisle to a second aisle on an opposite side of the first row of computers. The supply air duct is to be positioned with an upper section that is higher than a top surface associated with the first and second rows of computers. The cooling system includes a first wing to extend from the supply air duct toward the first row of computers, and a second wing to extend from the supply air duct toward the second row of computers.