The coupled system of evaporative cooling and solid desiccant dehumidification is feasible to solve the problems of energy consumption and air quality of data centers compared with the traditional cooling method. It is also one of the primary means of expanding the application scope and period of evaporative cooling technology in the southern humid and hot regions. A single-and double-stage solid desiccant dehumidification device filled with silica gel particles was designed and built in this study. Experiments were conducted during the transitional season in Guangzhou

a typical city in southern China’s humid and hot regions. Theoretical calculation models were also established. The results show that: better dehumidification performance can be achieved under 25.2 °C and RH 56.4%~74.9%; the maximum dehumidification efficiency and average dehumidification efficiency of the double-stage solid desiccant dehumidification system are 2 times and 2.9 times of the single-stage solid desiccant dehumidification system

respectively; and the time constants of moisture absorption rate β of the single-stage and double-stage solid desiccant dehumidification systems are between 0.35~1.00 and 0.33~1.18

respectively; the time constants of moisture ratio α are between 0.37~1.10 and 0.41~1.30; and the theoretical calculation model can fit the actual change curve well

with an average relative error below 10%.