WHAT ARE THE NECESSARY CONDITIONS TO ACHIEVE CLEAN ROOM CLEANLINESS?

Clean room cleanliness is determined by the maximum allowable number of particles per cubic meter (or per cubic foot) of air, and is generally divided into class 10, class 100, class 1000, class 10000 and class 100000. In engineering, indoor air circulation is generally used to maintain the cleanliness level of the clean area. Under the premise of strictly controlling temperature and humidity, the air enters the clean room after being filtered by the filter, and the indoor air leaves the clean room through the return air system. Then it is filtered by the filter and re-enters the clean room.

Necessary conditions to achieve clean room cleanliness:

1. Air supply cleanliness: To ensure the air supply cleanliness, the air filters required for the clean room system need to be selected and installed according to actual needs, especially the end filters. Generally, hepa filters can be used for 1 million levels, and below Sub-hepa or hepa filters can be used for class 10000, hepa filters with filtration efficiency ≥99.9% can be used for class 10000 to 100, and filters with filtration efficiency ≥99.999% can be used for class 100-1;

2. Air distribution: The appropriate air supply method needs to be selected according to the characteristics of the clean room and clean room system characteristics. Different air supply methods have their own advantages and disadvantages and need to be designed according to actual needs;

3. Air supply volume or air velocity: Sufficient ventilation volume is to dilute and eliminate indoor polluted air, which varies according to different cleanliness requirements. When the cleanliness requirements are higher, the number of air changes should be increased appropriately;

4. Static pressure difference: The clean room needs to maintain a certain positive pressure to ensure that the clean room is not polluted or less polluted to maintain its cleanliness.

Clean room design is a complex process. The above is just a brief overview of the entire system. The actual creation of clean room requires preliminary research, a large number of cooling and heating load calculations, air volume balance calculations, etc. in the mid-term, and a reasonable engineering design, optimization, engineering installation and commissioning to ensure the balance and reasonableness of the entire system.