4.2. Ventilation parameters
Research has shown that IAQ mainly involves three compo- nents (humans, fresh air and pollutants), and it is normal to seek a method to measure each of these components to evaluate IAQ in a space [80]. A detailed evaluation of the ventilation parameters such as air change rates, air exchange effectiveness and air exchange efficiency are critical in establishing how well the air distribution system operates. In order to attain an appropriate level of indoor air quality, acceptable air exchange effectiveness values and proper indoor pollutant concentration values are necessary [81]. The airflow through a room or a building is normally evaluated using one of the tracer-gas methods. All methods are based on a simplification of the continuity equation [40,82].