HVAC engineers

How Do We Calculate Required Airflow in a Cleanroom? In cleanroom engineering, airflow calculation is not a single-step process. It's a combination of multiple components that ensure cleanliness, pressurization, and system reliability. Total Airflow = ACH Airflow + Fresh Air + Leakage +Heat Load Air (converted) So how do engineers determine the right airflow? Step 1. Air Changes per Hour (ACH) Method This is the most widely used approach. Airflow = ACH × Room Volume Depending on the cleanroom classification: ISO 5  ⏩240-600 ACH ISO 6 ⏩ 90-180 ACH ISO 7 ⏩ 30-60 ACH ISO 8 ⏩ 10-25 ACH This ensures that the air inside the room is replaced multiple times every hour to maintain cleanliness. Step 2: Calculate Room Volume Room size: 10m x 5m x 3m Volume 150 m³ Step 3: Calculate ACH Airflow Formula: Airflow = Volume × ACH ACH Airflow = 150 x 25 = 3750 CMH Step 4: Add Fresh Air Typically 10-20% or as per standard Assume: 750 CMH Step 5: Safety Margin (5%) 5% of 3750 = 187.5 CMH Step 6: Add L...