Assuming that woods pellets would be dried with hot air, the energy that can be recovered depends of the outlet air temperature and saturation. If outlet temperature is greater than environmental air temperature, a heat recover (a heat exchange) may be installed at the drier output to pre-heat the input (environmental) air. If outlet air water vapor saturation is lower than 80%, a fraction of outlet air can be recycle to input air saving energy during input air heating. The quantification of this energy saving depends on the exact values of temperature and saturation of outlet air.