Often in industrial plants, heat in exhaust gases and/or in cooling waters is lost in the atmosphere and so wastes of energy occur. Entec, due to its constant attention to the environment sustainability, is looking for reaching high level of energy efficiency planning and realizing modern interventions of energy saving for all plants it is going to realize and for the existing plants. These interventions that permit an appreciable improvement of plant global efficiencies can be related to recovery of exhaust gases sensitive and latent heat, condensates heat and heat wasted in the atmosphere due to bad or inexistent caulking. White Certificates and Qualifications of Energy Efficiency can be obtained with these interventions.