On 4th and 5th September the VDEh seminar "Energieeffizienz in der Industrieofentechnik" took place once again. The given lectures showed which various measures in construction, equipment and operation can be applied to increase the energy efficiency of furnaces. Among others, the energy optimized process control plays an important role. Therefore Mr. Dr. Oertel was invited to acquaint the participants with this topic by a lecture on "Energy optimization by furnace models". In the lecture both the theoretical fundamentals and the practical application were explained, as well as the various functional modules of GIWEP furnace models that can be used to improve energy efficiency.