In this study, a completely new adsorption refrigeration system powered by biomass boiler, under condition of lower than 85°C driving hot water temperature was proposed. A numerical model of the whole system including the model of silica gel-water adsorption chiller, water tank, which reveals the transient operation process of the adsorption cooling system, is developed and verified by experiments. Parametric studies were performed using the model to determine the effect of parameters matching of components configuration and operation process on the cold generation capacity, the performance and the cyclic characteristics of the system, such as the chiller startup temperature, cooling and chilled temperatures, not only in the conventional cycle mode but also in direct cycle mode. The fluctuation of temperature in conventional cycle mode was significantly smoother than that in the direct cycle mode at heat source temperatures below 65°C. The cold delivered in the direct cycle mode was a little more fluctuating of the former but doesn't significantly reduce the performance of the machine. It was also found that the adsorption chiller could work efficiently on direct cycle mode under the conditions of heating temperatures of 60-65°C, with the COP of 0.33-0.4 and the cooling power of 3.8-4.15 kW while producing 10°C chilled water.