Air Changes Calculation Formula for an Injectable Area
The air changes calculation formula for an injection department, or any cleanroom environment, is as follows:
Air Changes Calculation Formula
ACH = (Total Airflow) / (Room Volume)
Where:
- ACH = Air Changes per Hour
- Total Airflow = Total airflow rate in cubic feet per minute (CFM) or cubic meters per hour (m³/h)
- Room Volume = Volume of the room in cubic feet (ft³) or cubic meters (m³)
Example Calculation:
Suppose we have an injection department with the following parameters:
- Room dimensions: 10 meters x 10 meters x 3 meters (height)
- Room volume: 300 cubic meters (m³)
- Total airflow rate: 10,000 cubic meters per hour (m³/h)
Using the formula:
ACH = (10,000 m³/h) / (300 m³) = 33.33 air changes per hour
Regulatory Guidelines:
The International Society for Pharmaceutical Engineering (ISPE) and the European Medicines Agency (EMA) provide guidelines for air changes in cleanroom environments:
- ISPE: 20-30 air changes per hour for injection departments
- EMA: 20-40 air changes per hour for Grade A and B cleanrooms
Read also:
Resource Person: Dr. Ghulam Abbas
