• If there are furnaces operating with a load lower than 50% of their capacity, this situation must be corrected, as this leads to unnecessary energy consumption;  
• If excessive use of transportation devices has been detected entering and leaving the furnace, there is an indication of poor energy use for heating such devices;
• If equipment operating with their doors not fully closed has been detected or the existence of cracks in doors, sills, hoods, these situations that reduce the thermal efficiency of furnaces should be corrected;
• Introducing loads for heating containing impurities or moisture represents unnecessary energy use and should be avoided;
• If the use of poorly insulated or uncovered crucibles is detected, electricity consumption can be reduced through a corrective action to recover the thermal insulation and placing covers on the crucibles;
• Check the possibility of reusing the heat originating from refrigeration systems, furnace cooling, exhaust gases;
• Whenever possible, preheat the load to be placed in the electric furnaces. This is a good application for the energy recovered from furnaces

Source: Manual for Efficient Energy Use in Industries, FIESC

Download: http://www2.fiescnet.com.br/web/pt/site_topo/energia/info/eficiencia-energetica-na-industria