Encon Thermal Engineers Pvt. Ltd. Manufactures Recuperators for Utilisation of Waste Heat. Encon Thermal Engineers Pvt. Ltd. Manufactures Heat Recovery Systems and Energy Management Systems, Furnaces and their allied equipments. The Recuperators for Utilisation of Waste Heat has been designed for utilisation of waste heat from exhaust flue gases of industrial furnaces. The temperature of flue gases is generally of the order of 600° C to 950° C. Thus, a considerable amount of heat energy, which may vary between 35 to 42% of the heat input to the furnace, goes to the atmosphere as a total loss.