Waste from plantation products has the potential to be used as an alternative fuel. Corn drying needs to be done to increase the selling price of the product and shelf life. One of the drying technologies is to use a bed dryer with the heat source coming from a biomass-fueled furnace. This study aims to determine the rate of heat transfer and analyze the efficiency of the furnace. This study was conducted at the Food and Postharvest Engineering Laboratory of FTP UGM as a tool design site, PT. Raja Pengering as a tool fabrication site, and in the Sukolilo Pati area as a tool testing site. The method used is direct testing with two variations of treatment, namely when the furnace is without a load and when the furnace is with a load. Variations of biomass fuel were carried out with teak wood, corn cobs, and rice husks of 10 kg each with one replication during the no-load furnace test. The main equipment used is a furnace with a vertical tube bank-type heat exchanger and an axial blower. The test results show the value of the heat transfer coefficient when the furnace is without a load of 142.59 W/m2.K, when the furnace is with a load of 138.74 W/m2.K. The coefficient of the furnace with the load is smaller because there is a load on the bed dryer so that the speed of air flowing in the tube bank is restrained. The heat transfer rates with wood, cob, and husk fuel are 22.5; 22; and 4.7 kW, respectively. The total energy of the furnace during combustion using wood, cob, and husk fuels were 83484.7; 33718.37; and 16125 kJ, respectively. The efficiency obtained with wood, cob, and husk fuels was 44.17; 32.67; and 11.65 %, respectively. The husks do not match the furnace design. The performance of the furnace with a load is that the average exit temperature of the furnace is 67.69°C with an efficiency of 68.87 %. Based on the results, the appropriate fuel is wood because it has a high calorific value so which produces an optimum temperature.