On the performances of a hybrid air-conditioning system in different climatic conditions

In previous papers the authors demonstrated that significant energy savings can be achieved in air-conditioning through the use of a hybrid plant in which a vapor-compression inverse cycle is integrated with an air dehumidification system working with hygroscopic solution and hydrophobic membrane. The advantage of this system lies in the fact that the refrigeration device operates at a higher evaporation temperature than that of a traditional system, in which dehumidification is achieved through condensation. In the proposed hybrid system the supplied air is simultaneously cooled and dehumidified in an air-solution membrane contactor. The LiCl solution is cooled by means of a vapor-compression inverse cycle. The solution is regenerated in another membrane contactor by exploiting the exhaust air and the heat rejected by the condenser. The paper reports a study of the steady-state behavior of the system in summer climatic conditions on varying some significant climatic parameters, such as the latent load of the conditioned space and the outdoor and indoor relative humidity. The performances of the hybrid system are compared with those of a traditional direct-expansion air-conditioning plant. Results of the simulations reveal that energy saving may exceed 60% when the latent load in the conditioned environment is high. (C) 2011 Elsevier Ltd. All rights reserved.