A measurement of the air flow velocities is required to determine the air exchange rate of a clean room. The test for uniformity of the air flow is also determined by measuring the air flow velocity.

Air flow and determination of the air exchange rate

In cleanrooms, controlled air circulation is crucial for maintaining the cleanroom class and therefore for the quality of the products produced. An important parameter for characterizing the air quality in a cleanroom is the air exchange rate, i.e. the number of air changes per hour.

The air exchange rate is determined by measuring the air flow. The airflow velocity is measured via supply air ducts and terminal filters.
Good airflow and an appropriate air change rate are crucial to minimize contamination in cleanrooms and ensure a clean working environment.

Determining the air exchange rate is therefore an essential part of the qualification of cleanrooms. The cleanroom class and the air quality requirements can be influenced by the air exchange rate. Regular monitoring and documentation of the air exchange rate is therefore essential to ensure the quality and reliability of cleanroom processes.


  • DIN EN ISO 14644-3
  • VDI 2083
  • EU GMP Guideline Annex 1
  • ZLG documents

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