A clean room refers to a space with good airtightness that controls air cleanliness, temperature, humidity, pressure, noise and other parameters as needed
According to the flow state of airflow
According to the flow state of the airflow, there are mainly the following three types of clean rooms with airflow distribution 
(1) Non-unidirectional flow clean room: It is often called a turbulent clean room before, and the airflow in the room does not all flow in a single direction. Non-unidirectional flow clean rooms have several common characteristics: the terminal filter (high efficiency or sub-efficiency) is as close as possible to the clean room, it can be the air supply port or directly connected to the air supply port, or it can be connected to the air supply static plenum in the room. ; The return air outlets are located in the lower part of the clean room, in order to avoid the phenomenon of "ashing". There are eddy currents in non-unidirectional flow clean rooms, which are not suitable for clean rooms with high cleanliness, but should be used in clean rooms of class 6 to 9.
(2) One-way flow clean room: The air flow of one-way flow clean room is characterized by parallel streamlines, flowing in a single direction, and uniform wind speed on the cross section. There are vertical one-way clean rooms, quasi-vertical one-way flow, and horizontal one-way flow. Convective clean room, etc.
(3) Vector clean room: air is supplied at the upper corner of the room, using a fan-shaped high-efficiency filter, or an ordinary high-efficiency filter with a fan-shaped air outlet, and a return air outlet in the lower part of the other side, the height of the room is higher than normal It is appropriate to be between 0.5 and 1. This clean room can also achieve Class 5 (Class 100) cleanliness.
The flow pattern of the clean room is basically the above three types, but many forms can be evolved in practical applications. The clean room can be a mixed flow pattern combining unidirectional flow and non-unidirectional flow to achieve a high level of clean room in a localized area (unidirectional flow section). For example, a "tunnel" (one side is open) with horizontal unidirectional flow is set up in the clean room, and the rest of the clean room is a unidirectional flow pattern of eddy current, so that the "tunnel" part can achieve a cleanliness level of 5 or higher, and the workbench Right in the "tunnel".
By properties of controlled particles
(1) Industrial clean room: a clean room in which the controlled particles are non-biological particles such as dust.
(2) Biological clean room: a clean room in which the controlled particles are biological particles.