This paper presents results for the minimization of fuel consumption in a batch furnace. Several different criteria are used and minimized with respect to time-dependent process and control variables. The results show that globally there is no significant difference between the solutions found, i.e. the choice of criterion - inergy, exergy, exergy destruction, entropy creation of the system and entropy creation of the system plus environment - does not significantly effect the global results. However, the specific details of each soution can, in fact, be quite different. In addition, it is shown that the application of optimization techniques to this type of furnace control problem can from a practical standpoint significantly reduce (by about 9% on an energy basis and 13.5% on an exergy basis) the overall consumption of fuel.