6. Discussion and conclusion
As shown in this article, there are five indices that can be used to
assess the performance of a ventilation system regarding air change
rate, pollutant removal, heat removal, exposure and air distribution.
The air exchange effectiveness is the effectiveness of different
ventilation systems in delivering the supply air to a particular point
in a room (for example, how quickly the air in the ventilated space
air is changed by fresh air). While the ventilation effectiveness for
the removal of contamination is defined to express how efficient
the pollutant is removed in the occupied zone or in the breathing
zone. Moreover, ventilation efficiency for the removal of heat is
defined to show how efficient the heat will be removed by the
ventilation airflow. As for personalised ventilation, the exposure
effectiveness is defined to see how the occupant is protected from
the exposure to the pollutant source. The air distribution system
has a major influence on various indoor environment parameters,
such as thermal comfort, indoor air quality, energy efficiency. The
assessment of air distribution depends on the purpose of the
airflow distribution, which might need different indices, like ADPI,
ADI or ADINew. In addition, the performance of different ventilation
systems will be determined by their specific tasks and such systems
could also be assessed by different indices.