The Role and Difference of Positive and Negative Pressures in Cleanroom Airflow

In the construction and operation of cleanrooms, the control of positive and negative pressures in the airflow is a crucial factor. It has a vital impact on the cleanliness of the workshop, product quality, and the safety of personnel and the environment. As a professional manufacturer of purification equipment, Guangzhou Cleanroom Construction Co., Ltd. will discuss in detail the role and difference of positive and negative pressures in cleanroom airflow with you today.

Maintaining a positive pressure in the cleanroom means that the air pressure inside the workshop is higher than that of the external environment. In this way, at the openings such as doors and windows of the workshop, the air will flow from the inside to the outside. It's like an invisible "air barrier" formed around the workshop, effectively preventing external dust, bacteria, harmful gases and other contaminants from entering the workshop. For example, in the cleanrooms for electronic chip manufacturing, positive pressure can prevent tiny particles in the air from adhering to the chips, affecting the performance and quality of the chips.

Positive pressure helps to maintain the orderly flow of air inside the workshop, continuously refreshing the air in the workshop. When a small amount of contaminants are generated inside the workshop, the airflow in the positive - pressure environment will promptly carry these contaminants away from key areas. After being filtered by the air purification system, the air is discharged from the workshop, ensuring that the entire workshop is always in a good clean state.

In some workshops that generate harmful gases, dust, or bio - aerosols, such as chemical laboratories and some areas of biopharmaceutical workshops, a negative - pressure design is adopted. Negative pressure makes the air pressure inside the workshop lower than that of the external environment, and the air will flow from the outside to the inside of the workshop. In this way, it can ensure that the harmful substances generated inside the workshop will not leak to the outside but are confined within the workshop. They are then discharged after being treated by a special exhaust system, avoiding harm to the surrounding environment and personnel.

For some cleanrooms involving high - risk operations, such as infectious disease research laboratories, the negative - pressure environment can effectively protect the safety of personnel outside the laboratory. Even if an accident occurs during the operation, such as the rupture of a container resulting in the leakage of harmful substances, the negative pressure can prevent the harmful substances from escaping from the workshop, reducing the risk of personnel exposure to dangerous environments.

The airflow direction in a positive - pressure workshop is from the inside to the outside of the workshop, while the airflow direction in a negative - pressure workshop is from the outside to the inside of the workshop. This difference in airflow direction directly determines their different functions in preventing contaminants from entering and controlling the diffusion of harmful substances.

Positive pressure is suitable for places that need to strictly protect the internal environment from external pollution, such as cleanrooms in the food processing and precision electronics manufacturing industries. Negative pressure is mainly applied to scenarios where harmful substances are generated and need to be prevented from leaking to the outside, such as chemical production and biosafety laboratories.

To achieve positive pressure, a cleanroom needs to be equipped with a suitable fresh - air system and air - supply equipment to ensure that the amount of air supplied to the workshop is greater than the amount of air discharged. A negative - pressure workshop, on the other hand, requires a more powerful exhaust system to ensure that the air in the workshop can be discharged in a timely manner. At the same time, the amount of fresh air entering needs to be strictly controlled to maintain a negative - pressure state.

The requirement for pressure control accuracy in a positive - pressure workshop is relatively low. Generally, it only needs to ensure that the pressure inside the workshop is slightly higher than that outside. In order to effectively control the diffusion of harmful substances, a negative - pressure workshop has a high requirement for pressure control accuracy. It is necessary to precisely adjust the air supply and exhaust volumes to ensure that the negative - pressure value remains stable within an appropriate range.

Guangzhou Cleanroom Construction Co., Ltd. has rich experience and a professional technical team. We can provide you with accurate solutions for positive and negative pressures in cleanrooms according to the different needs of customers. Whether it is the configuration of purification equipment for positive - pressure workshops or the system design, installation, and commissioning of negative - pressure workshops, we can provide you with one - stop services. If you encounter problems related to positive and negative pressure control during the construction or operation of cleanrooms, please feel free to contact us. Let's work together to create a safe, efficient, and clean production and working environment.