Thermochemical energy storage has a great potential in thermal energy storage attracting extensive attention in building's applications. However, performance issues of the thermochemical reactor should be tackled to improve the overall performance. To enhance the heat transfer within the reactor, this study proposes a thermochemical reactor integrated with copper fins. The reactor features both heated air and water output in a discharging process. Using Zeolite 13X as the thermochemical material, experimental tests have been conducted and presented in this paper to investigate the performance of the reactor. According to the experiment, the copper fins reactor achieves better performance in both charging and discharging compared with the reactor without fins. In charging, copper fins reactor reduces charging time by 0.75 h for the outlet air temperature reaching to the comparable level of the reactor without fins at 156.2 degrees C. In discharging, the copper fins reactor achieves the peak outlet air temperature at 54.6 degrees C and the peak outlet water temperature at 39.4 degrees C. Additionally, the reactor achieves energy storage density at 233 kWh/m(3) for material level and 128 kWh/m(3) for the reactor level. This paper provides valuable information for improving the reactor performance to achieve an optimal performance of a thermochemical energy storage system. (C) 2019 Elsevier Ltd. All rights reserved.