Clean rooms can be divided into four categories according to airflow organization 

1.Unidirectional clean room

The unidirectional flow clean room is also called the laminar flow clean room, which is divided into vertical and horizontal unidirectional flow airflow organizations. The airflow is parallel, straight and smooth from the indoor air supply side to the corresponding return air side. The pollutants from the indoor pollution source are pressed out of the room by the clean air before they spread into the room, and the clean air supplied has an isolation effect on the pollution source.

4.Mixed flow (local unidirectional flow) clean room

The general form of a mixed flow clean room is to make the entire clean room a non-unidirectional flow clean room, but the unidirectional flow type clean measures are adopted above the area where strict air cleanliness requirements are required, so that the area can obtain a unidirectional flow type clean area that meets the requirements, so as to prevent the relatively poor surrounding air environment from affecting the local high cleanliness.

 Clean room airflow organization design principles 

The main task of clean room airflow organization is to supply sufficient clean air, dilute and replace the pollutants generated indoors, and keep the indoor cleanliness within the allowable range.

Therefore, the design of clean room airflow organization should follow the following general principles:

1) The clean airflow sent into the clean room should diffuse quickly and be evenly distributed, so as to dilute the indoor air containing pollutants emitted by the pollution source as soon as possible and maintain the cleanliness required by the production environment.

2) To enable pollutants emitted into the clean room to be quickly discharged to the outside, to avoid or reduce air vortices and dead corners as much as possible, to shorten the retention time of pollutants in the room, and to reduce the chance of contact between pollutants and products.

3) To meet the air supply requirements of air conditioning such as temperature and humidity in the clean room and the comfort requirements of people.

Reasonable airflow organization can make the flow of indoor air meet the design requirements of the clean room, and ensure that the temperature, humidity, flow rate and cleanliness of the indoor air meet the process requirements and the comfort requirements of personnel.