In this study, changes in the heat recovery performance of the system under different operating conditions are investigated. A waste heat recovery device was installed for the experimental setup. A cross-flow plate heat exchanger made from cellulosic material is placed and thus heat transfer is ensured. Three different operating parameters were determined. Optimum conditions were determined by giving different values to these parameters. Statistical design of experiment (DOE) method was used for analyzes. As a result of the study, the values to be set for each parameter are explained in order to maximize the thermal effectiveness.