The energy efficiency of a plant is the ability to exploit the energy it supplied to meet demand: the less consumption for the fulfillment of a particular needs, the better the energy efficiency of the structure or system. Energy efficiency is a primary objective of energy policy in the industrial sector, indeed, the industry energy conspumption is among the main items of consumption in economic terms. The efficiency can be achieved through the "energy saving", in order to recover part of dispersed, for example, during the processes through exhaust fumes and steam, and reused in other thermal processes or sold to outside heating. To design, build and/or retrofit a system, a structure or an industrial building on the basis of energy saving technologies and the use of a reduced environmental impact, according to an Ecofactory model, is to rationalize consumption and energy costs in production, ensuring that opportunities for environmental benefit married to positive economic returns.