Nowadays, in order to decrease the energy consumption several efforts are made in different sectors. Concerning the aeronautical sector, numerous tests of aircraft engines are done to ensure their performances and safety. During this tests an important amount of thermal energy is wasted to the environment in form of hot exhaust gases. In order to recover, recycle and convert this waste energy, a solution could be represented by placing a recover heat exchanger in the chimney of the test bench. In this context, a reduced prototype model has been designed, manufactured and tested. In this thesis the characteristics of the heat exchanger and the test rig assembled to analyse its performances are described.