Abstract: An air supply and return system for heating and cooling a room, including an air flow loop having a first set of openings positioned high in a wall of the room (high vents) and a second set of openings positioned low in a wall of the room (low vents). The air flow loop includes a reversible air moving device, heating and cooling coils, and ducts connecting the reversible air moving device, filters, and the heating and cooling coils to the high vents and the low vents. During the cooling cycle, air is withdrawn from the room through the low vents, circulated with high air flow by the air mover through the ducts, filter, and the cooling coils, and discharged to the room from the high vents. During the heating cycle the air mover, and thereby the direction of air flow within the duct system, is reversed.