Air change per hour

ACH (Air Changes per Hour) measures how many times the full volume of air in a room is replaced with fresh or filtered air in one hour. It indicates the rate of air refreshing in a space.

Importance of ACH:

1. Indoor Air Quality (IAQ): Ensures removal of pollutants, ordor, or CO2 in order to get good IAQ.
2. Contaminant control: Important in sensitive environments, such as hospitals, laboratorys or cleanroom, etc., to dilute airborne pathogens or hazardous particles.
3. Thermal comfort: Enhances air circulation, ading in temperature and humidity control.
4. Energy consideration: Higher ACH improve ventilation however may increase energy use. So, it requires optimization.