Balancing air volume is the most important thing in cleanroom work.

Why is “adjusting the air volume balance” the most important thing in cleanroom work?
In cleanroom work, balancing the air is not a small tuning job, but it is the heart of cleanliness, safety, and standards. If the air is not balanced = the room is not clean, even if it is equipped with expensive HEPA.

1) Control the “direction of air flow” (Pressure Cascade). The clean room must force the air to flow from clean → dirty.
area pressure
Cleanest +++++
Cleanroom +++
Corridor +
Utility / Toilet −
👉 If Supply ≠ Return/Exhaust
➡ Blood pressure is broken.
➡ Dust/mold flows back into the room.

2) Maintain Cleanroom Class (ISO/GMP)
Each class requires a clear Air Change Rate (ACH). Approximate Class ACH.
ISO 8 20–30 ACH
ISO 7 30–60 ACH
ISO 6 60–90 ACH

❌ If the wind is "not complete"
 • ACH is below the limit.
 • Particle Count does not pass.
 • Audit / Validation failed immediately.

3) HEPA Filter will be "useless" if the air is not balanced.
HEPA requires a suitable Face Velocity (≈ 0.45 m/s).
 • Too much wind →
- Turbulence
- Dust clouds
 • Too little wind →
- Dead zone
- Accumulated dust
👉 Balance air = HEPA works at full efficiency.

4) Controls Laminar / Unidirectional flow in cleanrooms.
 • Need smooth, consistent wind.
 • No recirculation.

If not Balance:
 • Some winds are strong, some are weak.
 • Eddy / Swirl is born.
 • Dust is not blown away from the work area.

5) Controls leakage through the door & Airlock Airlock requires ΔP from the air volume.
Status Result
Wind balance is good, door open = wind blows out.
Wind balance broken, door open = dust sucked in.
👉 Many clean rooms “break” because the air is not balanced, not because the equipment is bad.

6) Reduce operational problems (Operation Problems) if the wind is not balanced, you will encounter
 • Users complain about strong wind/wind not reaching them.
 • Condensation at diffuser
 • Loud wind noise
 • High energy but ineffective results.

7) Balance wind = main condition of Commissioning in cleanroom testing must be passed.
 • Airflow Volume (CFM / m³/h)
 • Room Pressure
 • Recovery Time
 • Particle Count

❌ If it doesn't balance the wind → Do another test, no need to talk.

Short summary 
Cleanroom is not clean because of HEPA.
But it's clean because "the wind is properly balanced"