At first, a reference experiment was carried on the downdraft stove in order to determine the emissions, temperature profiles and pressure conditions during the operation of the stove in an unmodified state. This reference test is vital in the context of evaluating the effect of different modifications and changes in the stove which will be done in upcoming experiments. In Figure 2, the temperature profiles of different sections of the stove have been depicted. For every burning cycle, the stove was operated for the first 30 s in “up-draft” mode. After that, it was operated in downdraft (Twinfire mode) for the next 29.5 minutes. The average temperature in the grate was calculated to be around 750°C whereas, the temperature in the walls of the lower combustion chamber, where catalysts are planned to be installed in future experiments, was found to be ca. 650°C. In Figure 3, the timedepen — dent behavior of CO, VOC (Org.-C / THC) and aromatics (sum) has been depicted. These concentrations are recorded for four burning cycles of the reference test (Table 1).