An air-conditioning system with a thermally regenerated disccant was examined as a means of utilizing waste heat from micro-gas-turbine dynamos, which are becoming popular as private power sources. The individual machine elements such as desiccant rotors, sensible heat exchangers, evaporative coolers etc. were investigated to propose a new system configuration of air conditioning. The desiccant air-conditioning system was simplified and the cooling efficiency was improved by regenerating the desiccant rotors with the heat of the waste gas introduced directly into the regeneration air stream from the micro gas turbine dynamo, and by removing the adsorption heat without simultaneous humidification by an indirect evaporative coolers, in contrast to the conventional sxstem in which the regeneration air is warmed by heat exchange with hot water produced by waste heat. A field test unit of desiccant air-conditioning system equipped with a 1,220 mm diameter desiccant rotor was assembled in combination with a 30 kW micro-gas-turbine dynamo to supply about 60 kW cooling capacity.