Operators of industrial furnaces are some of the largest energy consumers in Germany. They pay energy suppliers about 30 billion euros per year. A tenth of this sum is for electricity, the rest for gas. 40 % of the energy consumed by German industry is for industrial furnaces. In 2005 energy consumption totalled 270 TWh (Terawatt-hours). This equals the annual consumption of 14 million private households.
CO2-emissions are reduced by 1.07 m3 with every m3 of natural gas. Saving 1 kg of domestic fuel oil means reducing CO2-emissions by 1.60 m3. The reduction in the consumption of electric energy is also visible in the CO2-balance of the energy suppliers, as producing energy means producing 520 g of CO2 per kWh (German energy mix).
Energy costs are rising and will continue to do so. Electricity prices for the German industry have skyrocked by 60 % since 2000 and gas prices have increased by no less than 250 % since 1999. For manufacturing industries, energy consumption is increasingly proving to be an increasingly critical factor with regard to their competitiveness. From a business management point of view, checking the energy efficiency of industrial furnaces has become more important than ever.
From a technical and economic perspective, evaluation and/or comparison of industrial furnaces is possible based on degrees of efficiency.
Depending on the temperature inside the furnace, its walls will be composed of one ore more layers of refractory materials, insulation material and blocking air layers. The choice of these refractory materials is made according to technical criteria but also from an economic perspective.