Air Change Principal
What is Air Change ?
Air change is the number of times the air within a space is replaced during a specified period such as hour or minute. It is usually expressed in changes per hour or per minute.
Air changes per hour
Abbreviated ACH or ac/h, is a measure of the air volume added to or removed from a space (normally a room or hall) divided by the volume of the space. If the air in the space is either uniform or perfectly mixed, air changes per hour is a measure of how many times the air within a defined space is replaced.
Air Change Rate
Air change rate is a unit of measurement that compares the amount of air moving through a defined space to the volume of the space. It is usually expressed as:
The below table shows the recommended designed air change for various type of work process & industry.
A factory measuring 20m x 20m X 3m wants to use Xtreme Cooler.
Area Volume: 20 x 20 x 3 = 1200 m3
Target air changes per hour = 30
Air flow required = 1200 x 30 = 36,000 m3/hr
Air flow of X3 is 18,000 m3/hr
Number of cooler required is 36,000/18,000 = 2 = 2 Coolers
The proposal would be of 2 units of X3 coolers together with balanced exhaust to maintain required positive pressure.