Tobacco has become one of the most important crops in Colombia, generating employment for both skilled and unskilled workers. In the post-harvesting of tobacco were found several problems to be solved, one of them concerning the high cost of the fuel used in the curing ovens. Therefore, an evaluation to the traditional heat exchanger, burner type, to determine the efficiency of the fuel used, was performed. The information obtained shows clearly the great difficulty that we have with this system of heat transfer by natural convection to maintain stable temperatures inside the oven, creating environmental conditions that deviate significantly from those required for this process, depending these variations largely on the frequency of loading of the burner, we also found that the use efficiency of the energy delivered by coal is less than 10 %.