This is the process when the utilised air is removed from the premises and it is replaced by fresh air. During this process, if there is a need or necessity, the air can be filtered, heated up or cooled down, humidified or dried. The process of air change in an enclosed space ensures:
- addition of O2 in the air;
- reduction of CO2 concentration;
- removal of excess water vapor;
- removal of air pollutants.
The simplest method for the ventilation of buildings is a natural method, when the air enters the premises through the cracks in the building, micro-ventilation openings, doors or specially designed vents. The air is removed through vertical extraction channels by the principle of natural extraction – convection, when the warmed up air rises upwards.
Another method of ventilation is mechanical. The air is supplied and removed from the premises by using ventilators.
Depending on the purpose, mechanical ventilation systems are divided into:
- exhaust systems, which remove the utilised air;
- supply systems, which supply outdoor air, which, if necessary, can be cleaned and heated up.