Abstract: An improved air conditioning system of the type wherein a conditioned fluid is conveyed from a central plant to a remote location where the fluid exchanges heat prior to being returned to the central plant for reconditioning. The system is provided with storage means for the fluid at the central plant and the remote location with a single conduit extending therebetween. Nonsimultaneously, pumps convey fluid through the single conduit from the central plant to the remote location and from the remote location to the central plant. In one embodiment, phase change may be employed to augment heat exchange capability at the remote location, or satellite.