Performance analysis of desiccant cooling systems in a hot and dry climate

Using desiccant cooling systems could help to significantly reduce greenhouse gas emissions from climate control systems in buildings, because this cooling technology employs an environmentally friendly refrigerant and low-grade energy sources such as solar energy. Here, the results obtained from a model of a desiccant cooling system are presented, as is the validation of that model using experimental data. The effectiveness of each component of the system (which included a desiccant wheel, heat exchanger, and two evaporative coolors) was assumed to be constant in the model. The main objectives of this work were to carry out a performance comparison of the ventilation, recirculation, and Dunkle cycles when the system was used in the hot and dry climate of Gabes (Tunisia), and to investigate the impact of the ambient conditions on the ventilation performance. Results showed that among the three cycles, the ventilation cycle presented the best coefficient of performance (1.89), while the coefficients of performance of the recirculation and Dunkle cycles were 1.13 and 1.71, respectively. Moreover, the ventilation mode was found to be strongly influenced by the ambient conditions and to be more efficient when the outside humidity ratio was below 18 g/kg.