ABSTRACTThe current article presents experimental results of the operation of top-lit updraft (TLUD) gasifier cookstove. The independent variables for the experiments are secondary airflow rate, the ratio of the secondary to the primary air flow rate, and the secondary air jet velocity. Based on the mass, temperature, and gas measurements the stove performance variables like effectiveness, combustion efficiency, AF, and power are calculated. The results show that varying the secondary airflow rate and jet velocities affect the fuel consumption rate for the flow rates considered. Combustion efficiency is relatively constant around 98%. Increasing the secondary air decreases the CO emission. Effectiveness starts to saturate beyond AF of 10. Useful power is found to be a strong function of secondary air.