The water contained in indoor pools is generally heated to 27-28 °C and this induces a high evaporation. The amount of steam is generally produced from a square meter of pool can vary from 100 to 250 g / h, depending on its temperature and physical activity of people present. To prevent any problems of condensation on the cold walls of the enclosure, or corrosion due to the presence of disinfectant agents in the water, it becomes necessary the installation of a dehumidification system. In most applications the dehumidifier integratesthe heating system of the air already present, in other systems it acts as a complete air handling unit enabling even the winter heating, summer cooling, heat recovery and fresh air treatment.