Due to the large number of people in closed spaces, and due to some applications in industrial environments, the polluted air has to be constantly or temporarily renewed. Ventilation systems aim to peg both the temperature and relative humidity of the air throughout the year, independent of the outside weather conditions.

A person leaves heat, carbon dioxide gas, water vapor and unpleasant odors to the ambient air. When a large number of people are in the same environment, in order to prevent the air from becoming rich in gaseous and smoky pollutants, it is necessary to ventilate this space, in other words, to send a sufficient amount of fresh air to this space. In industrial environments, ventilation is necessary in order for the production to be of high quality and to work comfortably.