Key Elements of Cleanroom Design

    Four basic components define a controlled environment:

 1) Cleanroom Architecture – Materials of construction and finishes are important in establishing cleanliness levels and are important in minimizing the internal generation of contaminants from the surfaces.

2) The HVAC System – The integrity of the cleanroom environment is created by the pressure differential compared with adjacent areas through heating, ventilation and air-conditioning system. 

The HVAC system requirements include:

    Supplying airflow in sufficient volume and cleanliness to support the cleanliness rating of the room.

    Introducing air in a manner to prevent stagnant areas where particles could accumulate.

    Filtering the outside and re-circulated air across high efficiency particulate air (HEPA) filters.

    Conditioning the air to meet the cleanroom temperature and humidity requirements.

    Ensuring enough conditioned makeup air to maintain the specified positive pressurization.

3) Interaction Technology - Interaction technology includes two elements: (1) the movement of materials into the area and the movement of people and (2) maintenance and cleaning. Administrative instructions, procedures and actions are necessary to be made about the logistics, operation strategies, maintenance and cleaning.

4) Monitoring systems - Monitoring systems include a means of indicating that the cleanroom is functioning properly. The variables monitored are the pressure differential between the outside environment and the cleanroom, temperature, humidity and, in some cases, noise and vibrations. Control data should be recorded on a routine basis.