Experimental assessment of the energy performance of a hybrid desiccant cooling system and comparison with other air-conditioning technologies

Desiccant-based air handling units (AHU) can allow significant energy saving and emissions reductions with respect to conventional air-conditioning systems. In this work, experimental tests are used to investigate a hybrid desiccant cooling system (DCS) with desiccant wheel (DW), interacting with a small scale cogenerator.Several new contributions are introduced by this study, such as the high number of operating conditions analyzed and of performance parameters used, the definition of a new COP and a comparison of the DCS with other air-conditioning options.The performance were analyzed varying five operating conditions: regeneration temperature, rotational speed, volume air flow rates, outdoor air temperature and humidity ratio. Several performance parameters, based on electric, thermal and primary energy, are investigated.Thermal performance of both the overall hybrid DCS and the DW reduce when regeneration temperature or flow rate increase, while electric and primary energy based parameters rise. Optimal operation is instead found for a narrow range of rotational speed.The hybrid DCS with microcogenerator is compared with other thermal or electrical air-conditioning technologies. The investigated DCS performs better or at least equal than the other thermally-activated systems, while the result of the comparison with the conventional electric unit depends on the outdoor air conditions.