Abstract: This invention provides a fundamentally new approach to air conditioning. In a conventional air-conditioning system air the full volume of air is cooled below the dew point to provide both sensible and latent cooling. In the new system, dehumidification and sensible cooling functions are preferably separate. The separate dehumidification allows for much higher supply air temperatures, preferably within about 10° F. of the space temperature. Low-velocity air distribution through a ceiling plenum or a vent into the space allows for very low fan static pressures, which greatly reduces fan energy use compared to conventional ducted systems. The low static pressures and high supply-air temperatures allow the use of existing drop ceiling construction with little modification. The system can also include low-cost thermal storage. Latent thermal storage is in the form of a concentrated liquid desiccant solution. Chilled water storage is another option.